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Mould in your home can become a danger to your health, and is often a sign that there is a damp problem that needs to be resolved before it causes severe damage to both you and your property.

Essentially, mould is a type of fungus which grows and spreads through microscopic spores that are then released into the air (which means if mould is in your home, then you’re breathing it in!). These spores can travel over long distances until they find somewhere to grow - typically in areas of poor airflow such as windows. 

Beware, it only takes a few spores to settle for mould to form - and it will continue to develop until it’s completely cleaned and removed.

Where will mould typically form?

Most commonly, you’ll find mould in the dampest places within your home - such as bathrooms. This is due to water vapour being released into the air when we have a bath or shower. If the room isn’t ventilated enough, the vapour will condense and eventually form damp patches.

Condensation is one of the most common causes of damp in the home - and it is this damp that unfortunately provides the perfect breeding ground for mould.

Condensation on a window

Without proper ventilation, mould will grow due to the build-up of condensation. This typically will occur from regular daily activities, such as drying clothes indoors, showering and cooking - all of which adds moisture into the air.

Another common cause of mould is humidity, and this is the reason that mould is primarily found in kitchens and bathrooms where steam is produced from cooking and showering. This steam then causes more humid conditions in these areas of the home in comparison to other rooms.

If you already have mould in your home, it can spread quickly so you need to act fast! At first, it can be hard to see, but within three weeks, it’ll have spread to a point where you can clearly see these patches on your walls.

Toxic black mould can be harmful - keep your eyes peeled!

As we mentioned at the start of this blog, mould can be very damaging to your health - so please don’t ignore it! Some species, known as ‘toxic black mould’ can be particularly hazardous, releasing chemicals - known as mycotoxins - and need to be removed by a professional.

Those who have conditions such as asthma, and individuals with weaker immune systems, can be greatly affected by mould - so if anyone in your household fits this criteria, it’s even more important to be vigilant.

Mould in the home

Typical symptoms as a result of mould includes wheezing, coughing, allergic reactions, sneezing, worsening asthma, respiratory infections and even depression as a result. If you have eczema, it can also make your skin significantly worse.

Mould can be cleaned from surfaces using products found in a supermarket - such as diluted bleach for example - but it will grow back quickly if you don’t alter your living conditions. As long as it is not a toxic black mould, it can be usually wiped off walls with a cloth (don’t forget to wear safety equipment such as gloves and glasses!).

If your mould is particularly stubborn, you may need to use toothbrushes, scrubbing brushes and paint scrapers to help remove it fully. Make sure that you get into the tight spaces too - which is where a toothbrush will come in particularly handy!

Don’t forget to throw away any materials that you’ve done your cleaning with so that the mould doesn’t spread even further throughout the home.

How do I reduce my chances of mould growing?

Firstly, if you do have mould, you’ll need to completely get rid of it before thinking about investing in a longer-term solution. Once the mould is completely gone, you can then look into increasing the amount of ventilation within your home.

The best way to reduce your chances of mould within your home is to increase ventilation to reduce the moisture in the air. The most effective way to do this would be to invest in a ventilation system - which will draw in fresh, filtered air from the outside and displace all of that mould-causing moist air.

MHVR units work by extracting the moist and stale air from more polluted sources - such as the kitchen, bathrooms and toilets - and supplies clean air (that is also heated from the warmth of the extracted air) into the home.

Get in touch with our team today for more information or if you have any queries - we’re happy to help!

Hay fever sufferers often dread spring and summer seasons due to the increased pollen count - which can summon an onset of nasty symptoms such as sneezing, blocked noses, itchy eyes and throat, coughs and headaches. 

When you’re outside, it can feel like there’s nowhere to escape pollen so going indoors, with the windows shut can offer welcome relief from symptoms.

However, without ventilation, homes and offices can become hot, stuffy and uncomfortable, with colds and viruses spreading very easily - but there is a solution!

What causes hay fever?

Hay fever is a seasonal allergy - often flaring up during the months from May through until September - and is caused by an immune system response to the inhalation of pollen, which is released by plants. 

There are typically two main peaks in the months of June and July, the warmest and sunniest months of the year, when grasses and other plants are most likely to release their pollen into the air.

Individuals can either be allergic to a specific type of pollen or may suffer a general immune reaction to all types (making it much harder to avoid). 

The biggest, most common cause of hay fever is grass pollen - simply due to the amount of grass that can be found when you’re out and about. Large fields of grass will release their pollen at a similar time, which elevates the pollen count within the air. 

It’s significantly worse on hot and breezy days too - as the wind will carry the pollen into your face, where it is either inhaled or comes in contact with your eyes.

Being airborne, pollen can easily be carried through open windows, as well as sticking to clothing, hair and animals.

The key to being symptom-free - keep pollen out

You’ll be happy to hear however, that there ARE actually ways that you can help to ventilate your home, whilst keeping your hay fever under control and your house nice and fresh!

The key to keeping your symptoms at bay is to reduce the amount of pollen that’s in your home at once. To do this, you’ll need to keep your windows and doors shut wherever you can - as this is one of the most common ways that pollen is brought into the house. 

Whilst you’ll struggle to prevent pollen from entering the home via the usual traffic in and out of your house, a Heat Recovery Ventilation Unit will allow this dirty air to be constantly circulated out of the home - with new, filtered air coming in.

The best solution, therefore, is to invest in a ventilation system which will do the hard work on your behalf. 

Ventilation systems - the most effective solution

A mechanical ventilation heat-recovery system is the most effective solution to your indoor hay fever woes. These energy-efficient systems will draw fresh air into the home through HEPA filters that remove pollen whilst dispersing clean air indoors. 

These systems often have two vents; one bringing filtered air in from outside, the other extracting it, creating a gentle flow of air through the home. As air is extracted, pollen, dust and other airborne particles are whisked away, preventing them from building up and keeping the air fresher, and more pure.

The system will also reduce the ingress of air through gaps around windows and doors by creating a higher air pressure in the building than outside, meaning that most of the air that enters the home will have been filtered by the ventilation system. 

If your ventilation system is efficient, then the levels of pollen within your home should not be able to build up to a point where it’ll trigger those pesky allergies - meaning that you’ll remain symptom-free in a cleaner, fresher, more comfortable home.


Contact us today to find out which ventilation system is right for you!

A study by the Royal College of Physicians, UK, titled 'Every breath we take: the lifelong impact of air pollution,' acknowledges that people spend approximately 90% of their time indoors. Given this, indoor air quality (IAQ) has a significant influence on our overall health and well-being. Despite being an area of increasing concern, awareness about indoor air pollution and its effects remains relatively low. This article aims to shine a light on the symptoms of poor air quality in a home, using UK-centric information where possible.

Physical Symptoms and Health Effects

Poor air quality indoors can lead to a range of health issues. The symptoms may be immediate, manifesting shortly after exposure, or long-term, appearing after prolonged or repeated periods of exposure.

Allergic Reactions

Poor IAQ is often linked to increased allergic reactions. UK's National Health Service (NHS) states that common allergens such as dust mites, mould, and pet dander can be present in significant amounts in households with poor air quality. Symptoms may include sneezing, a runny or blocked nose, itchy or watering eyes, wheezing, and coughing.

Respiratory Problems

One of the most telling signs of poor indoor air quality is a persistent cough, difficulty breathing, or other respiratory problems. High levels of pollutants such as volatile organic compounds (VOCs), tobacco smoke, radon, and carbon monoxide can trigger these symptoms. According to Public Health England, exposure to such pollutants can lead to chronic respiratory diseases over time.

Headaches, Dizziness, and Fatigue

Indoor air pollution can lead to general malaise, characterised by persistent headaches, dizziness, and unexplained fatigue. If you find relief from these symptoms when you spend time outside the home, it could be an indicator of poor indoor air quality.

Skin Issues

Dry or itchy skin can be another symptom of poor air quality. The presence of excessive pollutants or low humidity levels can irritate the skin, leading to dryness, itching, or rashes.

Subtle Indicators of Poor Indoor Air Quality

Besides the overt health effects, there are more subtle signs that can hint at poor indoor air quality.

Frequent HVAC System Issues

If your heating, ventilation, and air conditioning (HVAC) system requires frequent repairs or isn't controlling humidity levels efficiently, it might suggest poor indoor air quality. A well-functioning HVAC system plays a crucial role in maintaining a healthy indoor environment by managing humidity levels and filtering out pollutants.

Bad Odours

Persistent unpleasant odours can be a sign of indoor air pollution. These odours can arise from sources such as mould and mildew growth, which thrive in poorly ventilated areas with high humidity.

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Mould and Mildew

Visible signs of mould or mildew on walls, ceilings, or other surfaces in your home can indicate high moisture levels and poor ventilation, contributing to poor air quality.

High Dust Levels

If you notice dust accumulating quickly after cleaning or dust on your air vents, it may suggest that your home's air is not being filtered properly, leading to poor IAQ.

Improving Indoor Air Quality

Understanding the symptoms of poor indoor air quality is the first step towards healthier living spaces. Once you've identified a potential problem, steps can be taken to improve your home's air quality. This could include actions like ensuring your home is well-ventilated, maintaining your HVAC system, controlling humidity levels, or using air purifiers.

A report from the UK's Royal College of Paediatrics and Child Health (RCPCH) and the Royal College of Physicians (RCP) emphasises that air pollution indoors is a significant contributor to respiratory problems among children. Therefore, it's crucial not only to recognise the signs of poor indoor air quality but also to address them promptly to safeguard our health and that of future generations.

The Role of MVHR in Improving Indoor Air Quality

Mechanical Ventilation with Heat Recovery (MVHR) systems can play a significant role in enhancing indoor air quality and thus contribute to healthier living environments. MVHR is a controlled ventilation method that offers a systematic approach to maintaining optimal indoor air quality. It works by continually extracting stale, damp, and polluted air from inside the home and replacing it with fresh, filtered air from outside, while efficiently recovering the heat from the outgoing air to warm the incoming air.

Diagram of heat ventilation

Here's a more detailed look at how MVHR can improve indoor air quality:

Regulating Humidity Levels

By continuously extracting moist, stale air from rooms like kitchens and bathrooms, MVHR systems help to regulate humidity levels. This aids in preventing the growth of mould and mildew, organisms that thrive in damp conditions and can significantly impair indoor air quality.

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Eliminating Pollutants

MVHR systems filter the incoming air, thereby reducing the levels of pollutants such as dust, pollen, and external fumes. This is particularly beneficial for people with allergies or respiratory conditions, as it minimises their exposure to potential allergens.

Learn how to clean your filters in our article How Do You Clean MVHR Filters?

Reducing Condensation

By maintaining a balance between the air coming in and going out, MVHR systems reduce the likelihood of condensation, which can lead to dampness, mould growth, and ultimately, degradation in indoor air quality.

Learn more about condensation in our article What Causes Condensation?

Mitigating VOC Concentration

Volatile Organic Compounds (VOCs) are a significant concern in many homes and can emanate from various sources, including cleaning products, paints, and furnishings. MVHR systems help dilute the concentration of these compounds by ensuring a constant flow of fresh air.

Promoting Energy Efficiency

While this may not directly relate to indoor air quality, it's worth noting that MVHR systems recover heat from the outgoing air to warm the incoming fresh air. This process conserves energy, contributing to a more sustainable home environment without compromising air quality.

In summary, MVHR systems can make a significant difference in the indoor air quality of homes by ensuring a constant supply of fresh, filtered air and effectively managing humidity levels. However, it's crucial that these systems are properly installed and maintained to function efficiently. Regular cleaning or replacement of filters and a thorough check of the system by a qualified technician can ensure your MVHR system continues to support a healthy indoor environment.

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You probably assume that by cleaning your home every week - dusting, hoovering, mopping etc - you can make it a healthy environment. Unfortunately, this isn’t necessarily the case!

There are a number of habits and activities that we do (many of them without realising) that will contribute to a build-up of germs and unhealthy airborne particles within your home. This can lead to an array of nasty side effects, including asthma, headaches and other unpleasant skin conditions.

With summer coming up soon, it’s the perfect time to make the air in your home just as clean as that spotless toilet you’ve been bleaching.

  1. Limit the number of houseplants you own

Yes, houseplants might look lovely but they can also be lowering the air quality in your home.

Mould thrives in a wet, warm environment - meaning that the soil from your house plant is the perfect place for it to develop and grow.

Lots of people assume that plants make the air in a room better because they produce oxygen and take in carbon dioxide. There is a grain of truth in this, but it happens on such a small scale that it makes next to no difference in your home.

Mould and mildew spread through airborne spores, so if you do have plants, make sure you have good ventilation so these can be whisked away before they settle (or get inhaled).

If you really do love your indoor plants, we’d recommend having a couple of smaller plants, or one larger one, per room as a maximum - and make sure you keep your home ventilated.

  1. Dust

Dust mites are gross. They eat the skin cells you’ll shed as dust throughout the day and they’re attracted to dark, humid areas… like your bed.

People may feel constantly ill due to ‘hayfever’ or a recurring cold- when really, it’s just due to a high number of dust mites within your house.

dusting
Beautiful young woman makes cleaning the house. Girl rubs dust. Woman in protective gloves is smiling and wiping dust using a duster while cleaning her house.

Dust mites require a level of humidity to live so, as well as removing dust from your home by vacuuming and dusting regularly, you should also keep it well-ventilated to keep humidity levels low.

Good ventilation will also reduce the amount of dust in your home overall because it whisks it away before it can settle.

  1. Shut the lid when you flush

This one is gross.

When you flush the toilet with the lid open, a plume of tiny aerosol droplets which can contain bacteria and viruses are launched up to six feet away.

Pathogens such as E.coli, norovirus and even coronaviruses can be spread in this way, and the tiny droplets can remain airborne for hours.

If you think about what’s within six feet of your toilet, it’s probably enough to make you change your flushing habits.

However, 55% of UK adults don’t bother closing the lid when they flush so it’s a habit that’s hard to break.

This is why it’s important to make sure the air can be efficiently extracted from a bathroom through a window or with an extractor fan so that moisture doesn’t linger and airborne particles are sucked away.

  1. Clean and cover your bin

Nobody likes a disgusting ‘bin smell’ so make sure to regularly deep clean your household bin(s) with a strong disinfectant. The best way to do this is usually by placing it in the bath or shower and rinsing it with chemicals - just remember to clean your bath or shower afterwards too - or get the garden hose on it and wash the waste water down the drain.

It’s also essential that your bin has a well-fitting lid because as food waste rots, it produces mould and bacteria which can become airborne and produce bad smells. They also prevent flies from getting to your rubbish.

But some lids are better than others; if your bin has a lid that flips up when you press a pedal, the air current produced by opening can pump germs into the air.

So, as well as good bin hygiene, you should also ensure the air can change regularly with good ventilation.

  1. Increase your in-home ventilation

You may have noticed a recurring theme in the tips we’ve listed above. This is because a house can’t remain totally clean and hygienic without good ventilation.

Explained simply, ventilation is the introduction of outdoor air into an indoor space, controlling air quality by displacing indoor pollutants. By ventilating your home, you’re effectively stopping indoor air pollutants from damaging your health.

Always turn on your bathroom and kitchen fans before use and try to open windows for at least a short period of time (although this definitely isn’t easy to do in the middle of winter!). 

That being said, we’d recommend investing in one of our MVHR systems - which will circulate fresh air around your home without also sucking out heat. Fresh air from outside will be filtered and displaced throughout the house, which in turn filters out pollutants such as pollen, bacteria and dust mites.

You can find out more about our full range here, or get in touch today - we’ll be happy to help and offer our advice!

With energy prices soaring and the windows firmly shut to save energy this winter, most people have probably never been so aware of condensation. Worse than that, you’ve probably also noticed a few horrible, black splodges of mould.

Trying to avoid using gas or electric heating, many of us will have improved household insulation or spent time plugging draughts, unaware of the potentially dangerous consequences which must be considered.

Because, the more you insulate a house and prevent draughts, the more you need to ventilate.

Understanding mould

Mould and mildew develop within just 24-48 hours of water exposure and it will continue to grow until the moisture is eliminated. It can grow on just about any surface and it spreads through microscopic spores which float through the air and can cause serious health problems.

As soon as it’s spotted, it’s important that mould is cleaned away and that you prevent moisture from building in future - and this generally requires ventilation.

Ventilation, in its most basic sense, is easy; you just open a window or switch on an extractor fan. The problem is that this can make your home much colder in an instant.

So how can you ensure good ventilation without undoing all the good work you’ve done insulating or making your home more energy efficient?

Change the air, keep the heat

Mechanical ventilation heat recovery (MVHR) ventilation is a relatively new technology that’s more commonly used throughout continental Europe.

Whereas a basic extractor fan uses a fan to propel air from a room to the outside, an MVHR system replaces the extracted air with filtered fresh air which gets warmed by the air that’s being removed.

Using no more power than a typical extractor fan at just 40-60W (about the same as a non-LED lightbulb), this can save you a fortune on keeping your home warm while also keeping the air in your home fresh, clean and well-ventilated because 90% of the heat is retained.

It also has the added benefit of preventing the build-up of airborne germs so that viruses are less likely to spread within a household, and it can also remove airborne dust and other particles. Better still, it also prevents pollutants and allergens such as pollen from entering the home because the air is filtered as it comes in.

Easily installed and non-invasive

MVHR ventilation can be fitted to any kind of property. Typically, we install an inlet and an outlet into separate rooms so the air can flow through a home efficiently.

Outlets are normally installed in either the kitchen or bathroom, where the air is most likely to be humid, and inlets might be fitted in the bedroom or living room, while the MCHR unit itself is best installed in the loft or on an exterior wall.

With the main unit tucked away outside of the living areas, this means that the system is, to all intents and purposes, silent so the only indication that it’s on is the quality of the air and improved heat retention.

Airflow expertise

As a family-owned team that’s been supplying MVHR systems for ten years, we know ventilation inside out.

We offer cost-effective, high-performing systems that can make the air in any home safer, cleaner and more comfortable while also improving energy efficiency.


To find out more, please contact us today.

With the pollen count soaring as we head into summer, you might find you start to suffer from sore throats, streaming eyes and blocked noses on a daily basis.

Even if you spend the majority of your time indoors, this doesn’t guarantee that you’ll become symptom-free. We’ll explain why, and also what you can do to help…

What ACTUALLY causes hay fever?

Hay fever essentially is an allergic reaction to pollen - when it is inhaled or touches the nose/eyes, it triggers an immune response. The severity of response will vary greatly - with some being allergic to all plants, and others only some. 

Learn more about this in this article by AllergyUK

A woman blowing seeds off of a dandelion

The worst period for hayfever sufferers tends to be from May till the end of June (grass pollen) and August to September, when other plants release their pollen later on in the season. The windier the day, the worse your symptoms are likely to be, as the pollen is carried within the air.

How come it doesn’t help when I go inside?

Unfortunately for us, pollen grains are so small and lightweight that they can easily be picked up by slight gusts of wind and they can enter your home through most gaps.

Although you’re more likely to experience a reaction whilst you’re out and about, pollen particles are tiny and can travel far. Therefore, if you’re outside, you’re likely going to bring them back into the house on your clothes, footwear, hair and skin.

We’d recommend that any severe hay fever sufferers have a shower and wash their hair before sleeping. We’d also suggest getting changed away from your bedroom to avoid bringing the pollen into there. 

Pets are also notorious pollen spreaders as it sticks to their fur to be brought indoors.

Although you may think that keeping your windows shut is the best option to reduce the risk of pollen entering, it will also stop pollen from exiting - meaning that it can build up to high levels indoors as a result. 

Of course, shutting the windows can also mean your house gets uncomfortably hot on a warm, sunny day.

So, how can I help myself?

There are a few different methods to reducing your pollen count indoors - including washing your household items such as towels, bed sheets, sofa covers and cushions as much as possible. This will help to remove dust and pollen particles that may have settled there. Bedding is particularly vital to keep clean, as particles can attach themselves to you overnight, meaning that you’re likely to wake up with some nasty symptoms. Vacuuming can also help reduce pollen indoors.

Try to avoid getting pollen into your bedroom

Another suggestion is to ensure you take medication regularly whilst your symptoms are bad. There are many anti-allergy items on the market such as tablets, nose sprays, balms and eye drops that can help to make you feel better (but bear in mind, this won’t address the core problem of reducing pollen particles within your home!). 

The best way to reduce your pollen count indoors (and therefore your hay fever symptoms) is through good, constant air flow, provided that the air is filtered before entering your home. Ventilation systems like MVHR will draw the air into the building through HEPA filters - which are small enough to remove pollen - and disperse this fresh, clean air through the home. As the fresh air enters the house, the air that’s already indoors can be pushed or sucked back outside - taking dust and pollen along with it!

If you have an efficient ventilation system in place, the levels of pollen in your home should not build up to a point to trigger any allergies.


If you’d like to find out more, please contact us today for free, no-obligation advice.

Doing Your Research Is Important

Mechanical Ventilation with Heat Recovery (MVHR) is a popular ventilation solution for homes and buildings, providing a way to regulate indoor air quality, control temperature and humidity, reduce energy consumption, and meet Building Regulations. However, like any technology, MVHR systems have their own set of disadvantages that homeowners and building managers should be aware of before making a decision. In this article, we'll explore some of the disadvantages of MVHR systems.

High Upfront Cost

One of the main disadvantages of MVHR systems is their high upfront cost. Compared to other types of ventilation systems, such as natural ventilation or mechanical extract ventilation, MVHR systems can be significantly more expensive to install. The cost can vary depending on the size of the property, the complexity of the installation, and the specific MVHR system chosen. For homeowners on a tight budget, the high cost of MVHR systems may be a significant barrier to adoption.

Compare MVHR to Natural Ventilation in our article MVHR vs Natural Ventilation

Maintenance Requirements

Another potential disadvantage of MVHR systems is their maintenance requirements. Like any mechanical system, MVHR systems require regular maintenance to operate efficiently and effectively. This includes cleaning and replacing filters, inspecting ductwork and grilles, and checking for any signs of wear or damage. Failure to properly maintain an MVHR system can result in reduced performance, increased energy consumption, and potential health risks from poor indoor air quality.

Learn how to clean your MVHR Filters in our article How Do You Clean MVHR Filters?

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Noisy MVHR

MVHR systems can produce noise, which may be a disadvantage for some homeowners. The sound can be especially noticeable if the MVHR unit is located near living areas, such as bedrooms or living rooms. While some manufacturers have made efforts to reduce the noise produced by their systems, it's important to consider the noise levels when choosing an MVHR system.

Space Requirements

MVHR systems require space for ductwork, grilles, and the MVHR unit itself. Depending on the size of the property and the layout, this may be a challenge. For example, in smaller properties with limited attic or basement space, an MVHR system may be difficult to install.

Diagram Showing MVHR Unit in Loft Space

Climate Considerations

MVHR systems are designed to recover heat from exhaust air, which is advantageous in cooler climates where heating is required for most of the year. However, in warmer climates, the use of an MVHR system may be less effective. The system may require additional cooling to maintain comfortable indoor temperatures, which can increase energy consumption.

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The Truth

We only sell MVHR! So you might be asking yourself why we wrote this article. We believe it's important for you to have all of the information you need to make an informed decision, even if that means you learn that MVHR is not for you. MVHR systems offer many advantages, they are not without their drawbacks. The high upfront cost, maintenance requirements, potential noise, space requirements, and climate considerations should all be taken into account when considering an MVHR system. Homeowners and building managers should weigh the benefits against the disadvantages and consider their specific needs before making a decision.

MVHR In Summer

As summer approaches and temperatures rise, many homeowners use Mechanical Ventilation with Heat Recovery (MVHR) systems to keep their homes cool and comfortable. But how exactly does an MVHR system work in the summer months? Let's take a closer look.

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How MVHR Works

MVHR systems work by extracting stale, humid air from inside a building and replacing it with fresh, filtered air from outside. In the summer, this fresh air can be cooler than the air inside the building, providing a natural and energy-efficient way to cool the home.

The MVHR system achieves this using a heat exchanger, which captures the heat from the outgoing stale air and transfers it to the incoming fresh air. This process, known as heat recovery, ensures the home remains comfortable while minimising energy consumption.

Read more about how MVHR works in our article How Does MVHR Work?

How MVHR Works

When the outdoor temperature is cooler than the indoor temperature, the MVHR system essentially works in reverse. In this mode, the system extracts the warm air from the building and sends it outside, while bringing in cool air from outside. The heat exchanger transfers the heat from the outgoing warm air to the incoming cool air, ensuring that the home remains at a comfortable temperature without the need for air conditioning.

MVHR In Summer

MVHR systems can also help to regulate humidity levels in the summer. By extracting humid air from inside the home and replacing it with fresh, dry air from outside, the system can help to reduce the risk of mould growth and improve indoor air quality.

However, it's important to note that the effectiveness of an MVHR system in the summer will depend on a variety of factors, including the climate in your area, the size and layout of your home, and the efficiency of your system. In areas with high humidity levels, for example, the system may need to work harder to remove excess moisture from the air.

Learn more about condensation caused by excess moisture in our article What Causes Condensation?

MVHR Reduces Condensation In Summer & Winter

Keep It Maintained For Efficiency

To ensure that your MVHR system is working efficiently in the summer, it's important to keep up with regular maintenance, including cleaning the filters and ensuring that the ductwork is free of obstructions. You may also want to consider adjusting the settings on your system to optimise performance in the warmer months.

Learn how to clean your MVHR filters in our article How Do You Clean MVHR Filters?

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Conclusion: Does MVHR Work In Summer?

In conclusion, an MVHR system can be an effective and energy-efficient way to keep your home cool and comfortable in the summer months. By using a heat exchanger to transfer heat from the outgoing stale air to the incoming fresh air, the system can help to regulate temperature and humidity levels while minimising energy consumption. Just be sure to keep up with regular maintenance to ensure optimal performance.

Don't forget MVHR can help you meet Part F of Building Regulations

How Do You Clean MVHR Filters?

Mechanical Ventilation with Heat Recovery (MVHR) systems have become increasingly popular in recent years due to their ability to provide a constant supply of fresh, filtered air while recovering the heat from the outgoing stale air. These systems have filters that need to be cleaned regularly to maintain their efficiency and prevent the build-up of pollutants. So let's talk about how to clean MVHR Filters.

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Here are some tips for cleaning MVHR filters:

1. Understand the filter type:

Before cleaning the filter, it is important to understand the type of filter you have. Most MVHR systems have either a washable or a replaceable filter. Washable filters are made of a fine mesh that can be cleaned and reused, while replaceable filters are made of paper or other disposable materials and must be replaced periodically.

2. Turn off the system:

To clean the filter, turn off the MVHR system to prevent the fan from pushing dirt and debris deeper into the system.

3. Remove the filter:

Remove the filter from the MVHR system. This may require unscrewing a cover or removing a panel. Be sure to handle the filter carefully to avoid damaging it.

4. Clean the filter:

Washable filters can be cleaned with warm soapy water or a mild detergent. Rinse the filter thoroughly and let it dry completely before reinstalling. Replaceable filters should be replaced according to the manufacturer's recommendations.

5. Vacuum the system:

While the filter is out, use a vacuum cleaner to clean the interior of the MVHR system. Be sure to remove any visible dust or debris. Pay close attention to the fan blades and the heat exchanger, which are areas where dirt and debris can accumulate.

6. Reinstall the filter:

Once the filter is clean and the MVHR system is vacuumed, reinstall the filter. Make sure it is installed correctly and securely to prevent air leaks.

7. Turn on the system:

Turn the MVHR system back on and allow it to run for a few minutes to ensure proper airflow.

8. Regular maintenance:

Regular maintenance is crucial for the proper functioning of your MVHR system. Clean washable filters every 3-6 months, depending on usage, and replace disposable filters according to the manufacturer's recommendations.

In summary, cleaning the filters of your MVHR system is an essential part of its maintenance. Understanding the type of filter you have and following the manufacturer's recommendations for cleaning and replacing filters is crucial for the efficiency and longevity of your system.

Read more about how MVHR works, by reading our article What is MVHR?

In addition to the filters inside the MVHR unit, some systems also have in-line filters that are located in the ductwork. These filters may be more difficult to access and clean, but they are just as important for maintaining the air quality in your home. Here are some tips for cleaning in-line filters:

Identify the location of the filter:

The first step is to identify the location of the in-line filter. This may require a visual inspection of the ductwork or refer to the system's manual. In-line filters are typically located near the air intake or near the MVHR unit.

Turn off the system:

As with the filters inside the MVHR unit, turn off the system to prevent the fan from pushing dirt and debris further into the system.

Remove the filter:

In-line filters may be located in a filter box or a filter grille. Remove the filter box cover or the grille cover to access the filter. Be careful not to damage the filter or the ductwork.

Clean the filter:

In-line filters may be washable or replaceable. If the filter is washable, use warm soapy water or a mild detergent to clean it. Rinse the filter thoroughly and let it dry completely before reinstalling. If the filter is replaceable, replace it according to the manufacturer's recommendations.

Vacuum the ductwork:

While the filter is out, use a vacuum cleaner to clean the ductwork around the filter. Be sure to remove any visible dust or debris. Pay close attention to the area around the filter and the air intake, which are areas where dirt and debris can accumulate.

Reinstall the filter:

Once the filter is clean and the ductwork is vacuumed, reinstall the filter. Make sure it is installed correctly and securely to prevent air leaks.

Turn on the system:

Turn the system back on and allow it to run for a few minutes to ensure proper airflow.

Regular maintenance:

As with the filters inside the MVHR unit, regular maintenance is crucial for the proper functioning of in-line filters. Clean washable filters every 3-6 months, depending on usage, and replace disposable filters according to the manufacturer's recommendations.

In summary, cleaning in-line filters requires additional effort but is crucial for maintaining the air quality in your home. Identifying the location of the filter, turning off the system, removing the filter, cleaning the filter and ductwork, reinstalling the filter, and turning on the system are the key steps to follow. Regular maintenance is also important for the longevity and efficiency of the system.

MVHR can help your build meet building regulations part F.

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Does MVHR Alleviate Hayfever Symptoms?
Pollen blowing from a flower

What is MVHR?

MVHR is a ventilation system. The design extracts stale air from a building and replaces it with fresh air from outside. MVHR uses heat recovery technology to capture the heat from the extracted air. Then it transfers it to the incoming fresh air, which helps to reduce energy consumption and lower heating costs. Continue reading to find out if MVHR can actually alleviate hayfever symptoms!

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How does MVHR work?

MVHR uses a network of ducts throughout a building. These ducts connect to individual rooms and extract stale air from them. The air it extracts then passes through a heat exchanger, which transfers heat to incoming fresh air. The fresh air is then distributed throughout the building, providing a constant supply of clean air.

One of the key benefits of MVHR is that it helps to reduce the amount of pollen in indoor air. Pollen is a common allergen that can cause respiratory problems, particularly in people with asthma or allergies. During the hay fever season (March to September in the UK) the concentration of pollen in the air is higher. This can exacerbate hay fever symptoms. MVHR works by extracting the stale air that contains pollen and replacing it with fresh air from the outside. This helps to dilute the concentration of pollen in the air and reduce the risk of allergic reactions.

Does MVHR Alleviate Hayfever Symptoms?

Building Regulations and MVHR

Building regulations require that all new buildings are designed and constructed to meet certain standards of energy efficiency and ventilation. MVHR is one of the most effective ways to meet these standards. It provides a constant supply of fresh air while reducing energy consumption and heating costs.

The Building Regulations for England and Wales require that all new buildings have a minimum level of ventilation, which is measured in terms of the air changes per hour (ACH). The current minimum requirement is 5 ACH, which means that the entire volume of air in a building should be replaced five times every hour. However, this requirement can be difficult to achieve without the use of a ventilation system, particularly in modern buildings that are designed to be airtight.

MVHR is an effective way to meet the ventilation requirements of building regulations, as it provides a constant supply of fresh air while reducing energy consumption and heating costs. The system also helps to reduce the amount of pollen in indoor air, which can be beneficial during the hay fever season.

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Hay fever season in the UK

Hay fever is a common condition that affects around 20% of the population in the UK. The symptoms of hay fever, which include sneezing, runny nose, and itchy eyes, may worsen with poor indoor air quality. During the hay fever season, which usually runs from March to September, the concentration of pollen in the air is higher, which can make the symptoms of hay fever worse.

MVHR can help to alleviate hayfever syptoms by reducing the amount of pollen in indoor air. By extracting stale air that contains pollen and other pollutants and replacing it with fresh air from the outside, MVHR can help to dilute the concentration of pollen in the air and reduce the risk of allergic reactions.

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So, can MVHR Alleviate Hayfever Symptoms?

MVHR can help to improve the quality of indoor air by extracting stale air and replacing it with fresh air. One of the key benefits of MVHR is it can help to reduce the amount of pollen in indoor air.

Does MVHR Alleviate Hayfever Symptoms?
Pollen in a flower

Conclusion

In addition to its benefits for hay fever sufferers, MVHR also plays an important role in meeting building regulations. All new buildings in the UK must meet certain standards of energy efficiency and ventilation. MVHR is one of the most effective ways to achieve these standards. By providing a constant supply of fresh air while reducing energy consumption and heating costs, MVHR is an excellent investment for homeowners and building managers who are looking to improve the quality of indoor air and meet the requirements of building regulations.

Read about how MVHR also reduces condensation in our article What Causes Condensation?

In conclusion, MVHR is an effective ventilation system that can help to reduce the amount of pollen in indoor air, thus MVHR can alleviate hayfever symptoms. By providing a constant supply of fresh air while reducing energy consumption and heating costs, MVHR is an excellent investment for homeowners and building managers who are looking to improve the quality of indoor air and meet the requirements of building regulations. If you are a hay fever sufferer or if you are concerned about the quality of indoor air in your building, consider installing an MVHR system to enjoy the benefits of fresh, clean air.

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Open Windows

When it comes to indoor air quality and building regulations, ventilation is a critical component. Proper ventilation helps to ensure that occupants are breathing clean air while also reducing the risk of condensation and mould growth. However, there are two primary methods of ventilation: natural ventilation and Mechanical Ventilation with Heat Recovery (MVHR). In this article, MVHR vs Nautral Ventilation we will compare the two methods and explore the pros and cons of each.

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Natural Ventilation

Natural ventilation is a passive ventilation system that relies on natural air movement through open windows, doors, and other openings. This method does not require any mechanical components, which makes it a low-cost option. Natural ventilation also allows for fresh air to flow into the building, which can improve indoor air quality.

One of the biggest drawbacks of natural ventilation is that it is not as effective as MVHR. It can be difficult to control the flow of air, which can lead to issues with temperature regulation and condensation. Additionally, natural ventilation is not always feasible in urban areas where outdoor pollution levels may be high. Finally, natural ventilation may not always comply with building regulations, which require a certain level of ventilation to be maintained in order to prevent issues such as mould growth.

MVHR vs Natural Ventilation
Condensation on a window

Mechanical Ventilation with Heat Recovery (MVHR)

MVHR is a mechanical ventilation system that uses a heat exchanger to recover heat from the outgoing air and transfer it to the incoming air. This helps to reduce energy consumption while also improving indoor air quality. Unlike natural ventilation, MVHR systems are capable of controlling the flow of air, which can help to regulate temperature and prevent issues with condensation.

One of the main benefits of MVHR vs Natural Ventilation is that it can be more effective at reducing indoor pollutants and allergens. This is because the air is filtered as it is circulated through the system, which can help to remove dust, pollen, and other particles from the air. Additionally, MVHR systems are generally more efficient at maintaining a comfortable temperature throughout the building.

However, MVHR systems can be more expensive to install and maintain than natural ventilation. Additionally, they may require more complex controls and monitoring systems to ensure that they are operating correctly. Finally, MVHR systems must comply with building regulations, which require a certain level of ventilation to be maintained in order to prevent issues such as mould growth.

Read our article about condensation and the issues it can cause: What Causes Condensation?

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Condensation and Air Quality

One of the primary concerns when it comes to ventilation is condensation. Condensation occurs when warm air comes into contact with a cold surface, such as a window or wall. This can lead to issues with mould growth and can also contribute to poor indoor air quality.

Both natural ventilation and MVHR can help to prevent condensation by regulating the flow of air and maintaining a comfortable temperature throughout the building. However, MVHR systems are generally more effective at preventing condensation due to their ability to control the flow of air and regulate temperature.

MVHR vs Natural Ventilation
Installation diagram for MVHR

So, MVHR vs Natural Ventilation, Which Comes Out on Top?

When it comes to ventilation, there is no one-size-fits-all solution. The decision between natural ventilation and MVHR will depend on a variety of factors, including building design, location, and budget. While natural ventilation may be a more cost-effective option, it may not always comply with building regulations or be effective at preventing condensation. MVHR systems are generally more effective at regulating temperature and improving indoor air quality, but they can be more expensive to install and maintain.

Ultimately, the decision between natural ventilation and MVHR will depend on the specific needs and requirements of your building. By understanding the benefits and drawbacks of each system, you can make an informed decision that will help to ensure the comfort and safety of building occupants.

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Is MVHR Sustainable?
Is MVHR Sustainable?

Buildings are notorious energy consumers, with a substantial portion of their energy usage allocated to heating and cooling, approximately 40% of the total consumption. Consequently, there has been an escalating need for building systems that prioritise sustainability and energy efficiency. Enter mechanical ventilation with heat recovery (MVHR), an innovative system with widespread acclaim due to its exceptional energy-saving attributes. In this captivating blog, we will delve into the intricacies of MVHR, unravelling its inner workings, remarkable energy efficiency, and undeniable sustainability. Embark on this enlightening journey with us to determine the sustainability prowess of MVHR!

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What is MVHR?

Mechanical ventilation with heat recovery (MVHR) is a type of system that uses mechanical fans to circulate fresh air into a building while simultaneously extracting stale air. The system works by passing the incoming and outgoing air streams through a heat exchanger, which transfers heat from the outgoing air to the incoming air, preheating the incoming air during colder months and precooling it during warmer months.

MVHR is sustainable

How does MVHR work?

MVHR systems are designed to provide a constant supply of fresh air into the building while removing stale air. The system uses a heat exchanger to transfer heat between the incoming and outgoing air streams, thereby reducing the energy needed to heat or cool the incoming air.

The heat recovery process works as follows: the fresh air is drawn into the building through an intake vent and passed through a filter to remove any particulate matter. The stale air is simultaneously extracted from the building through an exhaust vent. The incoming and outgoing air streams pass through a heat exchanger, transferring the heat from the outgoing air to the incoming air. The preheated or precooled air is then circulated throughout the building using mechanical fans.

Read about how MVHR reduces condensation in our article What Causes Condensation?

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Energy Efficiency of MVHR:

MVHR systems are highly energy efficient as they use the heat recovered from the outgoing air to preheat the incoming air. This means that the system requires less energy to heat or cool the incoming air, which in turn reduces the overall energy consumption of the building. In fact, MVHR systems can reduce energy consumption by up to 90% compared to traditional ventilation systems.

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Sustainability of MVHR:

MVHR systems are sustainable as they reduce energy consumption and greenhouse gas emissions. The systems can be powered by renewable energy sources such as solar, wind, or geothermal, further reducing their environmental impact. Additionally, the constant supply of fresh air provided by the system can improve indoor air quality, which is beneficial for the health and well-being of building occupants.

Is MVHR Sustainable?
A typical home that could use MVHR

Conclusion:

MVHR is a sustainable and clever system that not only helps buildings reduce energy usage but also promotes cleaner and healthier indoor air. It works by using a heat exchanger to transfer heat from the outgoing air to the incoming air, preheating or precooling the incoming air. This reduces the energy needed to heat or cool the incoming air and results in significant energy savings. Additionally, the system can be powered by renewable energy sources, further reducing its environmental impact. MVHR systems are an excellent choice for sustainable building systems, providing a comfortable and healthy indoor environment while reducing energy consumption and greenhouse gas emissions.

MVHR is also a good way to meet Building Regulations for ventilation.

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How Does MVHR work?

How Does MVHR Work?

Breathing in clean air is essential for our health and well-being, but what about the air inside our homes and buildings? Mechanical Ventilation with Heat Recovery (MVHR) is a system that ensures proper air circulation. It does this while maintaining air quality, and reducing energy consumption. In this article, we'll first take a closer look at how this sustainable and energy-efficient system works Then we will discuss its benefits, and why it's crucial in modern-day architecture. So, let's dive in and discover how MVHR can improve the air quality in your home or building, reduce heating costs, and promote sustainability; How does MVHR Work?

Mechanical Ventilation with Heat Recovery (MVHR) is an energy-efficient and sustainable method of ensuring proper air circulation within homes and buildings. In fact, it is a system that allows fresh air to circulate in and stale air to circulate out. This process not only maintains air quality but also promotes energy efficiency and sustainability.

MVHR is a relatively simple system that operates by recovering the heat from the extracted air and using it to heat the fresh air being circulated into the building. In this article, we will delve deeper into the workings of the MVHR system, its benefits, and why it is crucial in modern-day architecture.

Read more about this in our article What is MVHR?

A Diagram that shows how MVHR Works
Diagram of how MVHR works

The Basic Principle of MVHR

How does MVHR work? The MVHR system extracts stale, moist air from the interior spaces of a building, such as kitchens, bathrooms, and utility rooms, and replaces it with clean, fresh air from the outside through a duct network that runs through the entire building.

The ducts pull in fresh air from the outside and pass it through a heat exchanger, while the system uses the extracted stale air to heat the fresh air. The heat transfer occurs between the stale air and the fresh air, which is then circulated back into the building. This process warms the incoming air and prevents heat loss to the outside environment.

The system expels the extracted stale air from the building, and the central unit automatically controls and monitors the air quality to adjust the system accordingly, ensuring a continuous process.

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The Benefits of MVHR

The MVHR system has numerous benefits that make it an ideal choice for modern-day architecture. Some of these benefits include:

  1. Improved Air Quality: MVHR systems ensure that the air inside the building is of high quality. The system filters out dust, pollen, and other pollutants, ensuring that occupants breathe clean air.
  2. Energy Efficiency: The MVHR system recovers heat from the extracted stale air and uses it to heat the fresh air being circulated into the building. This process ensures that energy is not wasted, and heating costs are reduced.
  3. Reduced Moisture Levels: Moisture is a common problem in buildings, and it can lead to mould growth, which can be harmful to health. The MVHR system extracts moisture-laden air from the building, reducing moisture levels and preventing mould growth.
    Read more about condensation in our article What causes condensation?
  4. Noise Reduction: The MVHR system operates quietly, reducing noise levels in the building.
  5. Enhanced Comfort: The MVHR system maintains a constant temperature throughout the building, ensuring that occupants are comfortable at all times.
  6. Sustainability: The MVHR system is a sustainable solution that promotes energy efficiency and reduces carbon emissions. It is an excellent choice for eco-friendly buildings.
MVHR Reduces Condensation
Condensation on a window

Why MVHR is Crucial in Modern-Day Architecture

Modern-day architecture places a strong emphasis on energy efficiency, sustainability, and comfort. The MVHR system is an ideal solution that meets all these requirements. It is a simple, yet effective system that ensures proper air circulation maintains air quality and reduces energy consumption.

In addition, the MVHR system is easy to install and maintain, making it a cost-effective solution for modern buildings. It is an excellent choice for residential buildings, commercial buildings, and public spaces such as schools and hospitals.

Not to mention the need to meet building regulations.

Conclusion

In answer to the question, how does MVHR work? the MVHR system is an energy-efficient and sustainable solution that promotes proper air circulation maintains air quality and reduces energy consumption. It is an ideal choice for modern-day architecture, where energy efficiency, sustainability, and comfort are essential. The system is easy to install and maintain and has numerous benefits that make it a cost-effective solution for residential, commercial, and public buildings. If you are considering building a modern, eco-friendly building, the MVHR system should be at the top of your list

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style="color: #25a244"

Mechanical Ventilation with Heat Recovery (MVHR) systems are popular for their ability to improve indoor air quality and energy efficiency. However, many people are still unsure about whether or not MVHR systems can heat or cool a house. In this article, we explore the functions of MVHR systems and how they can affect the temperature in a building.

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What is an MVHR system?

MVHR is a ventilation system that uses a heat exchanger to recover heat from the outgoing air. The MVHR system then transfers this heat to the incoming air. This results in a more efficient ventilation process, as the system can maintain a constant flow of fresh air into the building without the need for additional heating or cooling.

These ventilation systems will help you meet building regulations for ventilation.

How does an MVHR system work?

An MVHR system works by extracting stale air from inside the building through a series of ducts and filters. The stale air is then passed through a heat exchanger, where the heat is transferred to the incoming fresh air. The fresh air is then distributed throughout the building, while the stale air is expelled outside.

The heat exchanger in an MVHR system can recover up to 95% of the heat from the outgoing air. This can significantly reduce the amount of energy needed to heat the building. Additionally, the system can also extract moisture from the incoming air. Reducing this moisture can help to control humidity levels and prevent the growth of mould and other harmful bacteria.

To learn more about this read our article What is MVHR?

Can MVHR Heat or Cool a Property?
The layout of an MVHR system

Can an MVHR system heat a house?

While an MVHR system is primarily designed for ventilation purposes, it can also help to heat a house. By recovering heat from the outgoing air, the system can reduce the energy needed to heat the incoming fresh air. This means that the temperature inside the building can be maintained without the need for additional heating.

However, it is essential to note that an MVHR system is not a heating system in itself. It can only help to supplement the heating system in the building. It does this by reducing the amount of energy needed to maintain a comfortable temperature.

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Can an MVHR system cool a house?

The design of MVHR is not meant to cool a house in the same way as an air conditioning system However, the system can help to reduce the temperature inside the building by providing a constant flow of fresh air.

During the summer months, the incoming fresh air can be cooled using a mechanical cooling system or a natural ventilation strategy, such as opening windows at night to allow cool air in. The cooled air is then passed through the heat exchanger in the MVHR system, where the heat is transferred to the outgoing stale air.

While an MVHR system cannot provide the same level of cooling as an air conditioning system, it can help to reduce the need for additional cooling and improve the overall comfort of the building.

Can MVHR Heat or Cool a Property?
Condensation on a window in a house with inadequate ventilation

What are the benefits of an MVHR system?

There are several benefits to installing an MVHR system in a building, including:

Improved indoor air quality: An MVHR system can help to remove pollutants, allergens, and other harmful particles from the air, resulting in improved indoor air quality and better health for occupants.

Energy efficiency: By recovering heat from the outgoing air, an MVHR system can significantly reduce the amount of energy needed to heat a building, resulting in lower energy bills and reduced carbon emissions.

Comfort: An MVHR system can help to maintain a constant temperature and humidity level inside the building, resulting in improved comfort for occupants.

Noise reduction: An MVHR system can help to reduce noise levels inside the building by providing a constant flow of fresh air, which can help to mask external noises.

Reduced condensation: By extracting moisture from the incoming air, an MVHR system can help to reduce condensation inside the building, which can help to prevent mould growth and other moisture-related problems.

Learn more about the issue caused by condensation in our previous article What Causes Condensation?

So, Can MVHR Heat or Cool a Property?

In conclusion, an MVHR system can help to heat or cool a house, but it is not a standalone heating or cooling system. MVHR supplements the existing heating or cooling system in the building by improving ventilation and reducing the amount of energy needed to maintain a comfortable temperature. The system can recover up to 95% of the heat from the outgoing air, which can significantly reduce the amount of energy needed to heat the building. Additionally, the system can also help to reduce the temperature inside the building by providing a constant flow of fresh air. Natural ventilation or mechanical cooling can help to cool this air.

Overall, an MVHR system is an excellent investment for those looking to improve indoor air quality. Additionally, it can help improve energy efficiency, and comfort levels in their homes or buildings. MVHR cannot replace a heating or cooling system, however, it can certainly help to supplement it and reduce energy costs. With correct installation and maintenance, MVHR can provide reliable service for years. MVHR also contributes to a healthier, more comfortable living environment.

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MVHR vs HVAC, what's the difference?
Ventilation Grilles on a rooftop

When it comes to heating, ventilation, and air conditioning (HVAC) systems, there are a few different options. One increasingly popular choice is mechanical ventilation with heat recovery (MVHR). But what exactly is MVHR, and how does it differ from traditional HVAC systems? MVHR vs HVAC, what's the difference? Let's take a closer look.

What is HVAC?

First, let's start with the basics: what is HVAC? HVAC refers to a building's heating, ventilation, and air conditioning systems. These systems work together to maintain a comfortable and healthy indoor environment.

Heating: The heating system is responsible for keeping the indoor temperature warm. Done usually by heating air or water and distributing it throughout the building.

Ventilation: The ventilation system is responsible for bringing fresh air into the building and removing stale air. This is important for maintaining indoor air quality and preventing the buildup of pollutants and allergens.

Air conditioning: The air conditioning system is responsible for cooling the indoor temperature. This is done by removing heat from the air and releasing it outside.

In traditional HVAC systems, these three functions are often under the control of a thermostat. The system may use a central air handler to circulate air throughout the building. However, it may use individual units in each room.

MVHR vs HVAC, what's the difference?
How MVHR works

What is MVHR?

Mechanical ventilation with heat recovery (MVHR) is a type of ventilation system. The design intention is to be more energy efficient than traditional HVAC systems. MVHR works by using a heat exchanger to recover heat from the air it vents out of the building. MVHR then uses this air to warm up the fresh air it brings in.

In an MVHR system, there are two separate air streams: one that brings fresh air into the building, and one that removes stale air. The two streams are separated by a heat exchanger, which allows heat to be transferred from the outgoing air to the incoming air.

Because the incoming air is pre-warmed, less energy is required to heat it up to the desired temperature. This makes MVHR systems more energy-efficient than traditional HVAC systems, which simply vent out warm air and replace it with cold air.

Read more about this in a previous article What is MVHR?

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What are the differences between MVHR and HVAC?

Now that we understand what both MVHR and HVAC systems are, let's take a closer look at some of the key differences between the two.

Energy efficiency: One of the main differences between MVHR and traditional HVAC systems is energy efficiency. MVHR systems use a more energy-efficient design than traditional HVAC systems, as they use a heat exchanger to recover heat from the outgoing air.

Indoor air quality: Another important difference between MVHR and HVAC systems is their impact on indoor air quality. MVHR systems provide a constant supply of fresh air, which can help to reduce the buildup of pollutants and allergens. HVAC systems, on the other hand, may not provide as much fresh air and may be less effective at removing pollutants from the air.

Read about the risks of condensation in our previous article What Causes Condensation?

Cost: MVHR systems can be more expensive to install than traditional HVAC systems, due to the need for a heat exchanger and other specialized components. However, they may be more cost-effective in the long run due to their energy efficiency.

Maintenance: Both MVHR and HVAC systems require regular maintenance to ensure that they are functioning properly. However, MVHR systems may require more specialised maintenance due to the complexity of the heat exchanger and other components.

Noise: HVAC systems can be quite noisy, particularly if they use central air handlers that are located in the building. MVHR systems are typically quieter, as the air flows through ducts and is distributed through individual vents.

MVHR vs HVAC, what's the difference?

Conclusion

In summary, HVAC systems provide heating, ventilation, and air conditioning to buildings. While MVHR systems can regulate the air temperature while providing fresh air to the building and removing stale air. However, MVHR systems use a more energy-efficient design than traditional HVAC.

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Positive Input Ventilation

Ventilation is ventilation, right? Well, no. Different types of ventilation, while achieving similar results, work in different ways which may better suit your needs. Consequently, you really need to look at all types - MVHR, PIV etc. - to understand the differences. This article discusses Positive input ventilation: Pros and cons.

Ventilation Megastore manufactures, and sells, only Mechanical Ventilation with Heat Recovery (MVHR), but we think it is important for you to have all of the information you need to make the correct, educated choice for you.

In some circumstances, PIV will be the way you need to go, or you may simply prefer how it works for your property.

Now, Let's look at what PIV is, and how it works.

Positive Input Ventilation
An example of a Positive Input Ventilation unit from Vent Axia

What is Positive Input ventilation (PIV)?

Positive Input Ventilation (PIV) is a type of ventilation system that works by drawing fresh air from outside and subsequently circulating it throughout the property. Installation in new and existing properties is an effective solution for improving air quality, reducing condensation, and preventing mould growth.

Looking to improve your home's air quality? Consider positive input ventilation! In this article, we'll explore the pros and cons of PIV systems, helping you make an informed decision about whether they're right for your home.

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Pros of PIV

Improves indoor air quality

PIV works by constantly circulating fresh air throughout the property. This helps to remove pollutants, allergens, and other harmful substances from the air, improving indoor air quality. This is particularly important for people who suffer from allergies or respiratory issues.

Reduces condensation and prevents mould growth

Condensation is a common problem in many properties, especially in colder months. PIV can help to reduce the amount of moisture in the air, preventing condensation from forming on windows, walls, and ceilings. This, in turn, helps to prevent mould growth, which can cause serious health problems.

Read more about the problems caused by condensation in our previous article What Causes Condensation?

Energy-efficient

PIV is an energy-efficient solution for ventilation. It uses a low-wattage fan to circulate air, which is much more efficient than other forms of ventilation, such as extractor fans. This can help to reduce energy bills and lower carbon emissions.

Easy to install

It is relatively easy to install PIV without major disruption to the home. You can fit PIV to existing ducting, or install a new system, depending on the needs of the property. This means that homeowners can enjoy the benefits of PIV without having to undergo major construction work.

Low maintenance

PIV requires very little maintenance, making it a hassle-free solution for homeowners. The filters need to be changed regularly, but this is a simple task that can be done by the homeowner.

Positive Input Ventilation

Cons of PIV

Noise

One of the most common complaints about PIV is that it can be noisy. The low-wattage fan used in the system can produce a humming noise, which can be disturbing to some people. However, newer models are much quieter than older ones, so this is becoming less of an issue.

Initial cost

In addition, the initial cost of installing a PIV system can be quite high. However, this cost can be offset by the energy savings that are achieved by using the system. In addition, many manufacturers offer financing options or payment plans to make the cost more manageable.

Not suitable for all properties

PIV is not suitable for all properties. It works best in properties that have a high level of air leakage, as it relies on the flow of air to circulate throughout the property. In properties with very low air leakage, such as modern, airtight homes built to building regulations, it may not be as effective. In addition, PIV may not be suitable for properties located in areas with high levels of pollution or allergens.

Potential for drafts

PIV can cause drafts in some properties. This is because the fresh air is circulated throughout the property, which can create a flow of air that can be felt by occupants. This is not a major issue, but some people may find it uncomfortable.

May not be effective in all climates

PIV may not be as effective in all climates. In cold climates, it may not be as effective at reducing condensation, as the air that is brought in from outside will be cold and may increase the risk of condensation. In very hot climates, it may not be as effective at reducing indoor temperatures, as the air that is brought in from outside will be hot.

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Conclusion:

PIV is an effective solution for improving air quality and, in addition, reducing condensation in the home. It is energy-efficient, easy to install, and low maintenance, making it a popular choice among homeowners. However, it is important to consider the potential drawbacks, such as noise, initial cost, and the potential for drafts, before making a decision.

If you are considering installing a PIV system in your home, it is important to consult with a professional to determine if it is the best solution for your specific needs. They can evaluate your property and climate to determine if PIV is suitable and recommend any other types of ventilation that may be more effective.

Overall, PIV is a great solution for improving indoor air quality and reducing condensation in the home. It has many benefits, including energy efficiency, ease of installation, and low maintenance. However, it is important to carefully weigh the pros and cons before making a decision.

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Can You Retrofit MVHR?
A typical home that could use MVHR

Can you retrofit MVHR?

Can you retrofit MVHR? Perhaps the question should really be, Can I Add MVHR to My Property? The answer will really depend on the fabric of the property, or the layout. 

What is MVHR?

Mechanical Ventilation with Heat Recovery (MVHR) is a whole home ventilation system. It works by extracting the stale, moist, and polluted air from the inside of your home or other property. It then resupplies with fresh, filtered air. 

At the same time, the air travels through a heat exchanger. This then transfers a large percentage of the heat energy from the extracted air to the incoming air, resulting in a more energy-efficient building when installed correctly.

This creates a more comfortable, condensation and mould-free environment year-round.

Read more about this in our previous article! What is MVHR?

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Build with MVHR In Mind

In an ideal situation, you would want to build a property with MVHR in mind, planning for ducting work, electrical cables and the site of the Unit at the very least. Even better, MVHR would be installed as you build. 

Read more about why in our previous article, When in the Building Process Should I Design My MVHR System?

Retrofitting does come with its drawbacks, especially in some older properties with no wall/ceiling cavities, as this would make it difficult or impossible to hide the ductwork.

This does not make it impossible though, to install MVHR in such a property.

A typical building site

Retrofitting MVHR into Older Buildings

Older buildings are often quite leaky, but ventilation in old buildings is still important. This may seem odd as usually, we try to make older buildings more airtight, sealing holes and gaps. While this is important to stop cold air from getting in, airtight buildings have no air circulation which can create condensation and mould. This is why mechanical ventilation is important.

It is often said that older buildings do not benefit from MVHR, however, this is not the case. It may not be as efficient as it is in newer buildings but there are still benefits, such as:

Read more about this, and installing MVHR in new builds in our article, Is MVHR Suitable for My Property?

There will be occurrences where not all rooms in an older property can have MVHR ducting run directly to them due to their construction. However, it will be possible to install it on the top floor, allowing for bedrooms and bathrooms to be condensation and mould-free.

Read more about it in our previous article Are MVHR Systems Worth It?

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How Airtight Should a Property Be For MVHR?

The more airtight a property starts before MVHR, the better. However, this does not mean that MVHR does not benefit “leakier” properties. 

MVHR will still improve indoor air quality in a leakier property for example.

The efficiency however is much greater with an actual airtightness level of 3 m3/(hr.m2) or lower.

Generally speaking, newer, building regulation-meeting properties will be more airtight, and older buildings will be “leakier”. Renovated buildings have their own level of regulations to meet, and will generally be quite airtight. 

Read more about MVHR efficiency in our previous article How Efficient are MVHR Systems?

Can You Retrofit MVHR?
A village road full of older homes

If you Insulate, you must Ventilate

In the days before loft insulation, wall insulation, or even double glazing, this vapour-filled, humid, stale air would have escaped through background ventilation. Ill-fitting doors and windows for example would have allowed this air out, and replaced it with fresher, colder air. If you have ever felt a draught, you’ve experienced this process.

In new builds or renovations that meet building regulations, however, this air cannot escape so easily. With the addition of energy-saving measures such as double glazing, cavity wall insulation and draught-proofing, there is little to no natural ventilation. This leads to a build-up of vapour-filled air being trapped in the property without the addition of proper ventilation.

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Daily Tasks that Cause Condensation

We all bathe or shower regularly, but other things we do regularly also cause condensation. Some examples are:

The average family of 4 will contribute around 4 pints of water per person each day just by doing these tasks, which equals around 100 pints of water vapour every week!  With poor ventilation, this vapour will likely turn into condensation.

Read more about the problems condensation can cause, in our article What Causes Condensation?

Condensation on a window

What Is The Lifespan of MVHR?

On average, the lifespan of an MVHR unit will be around 15 years. This does not however mean that the whole unit will need replacing after 15 years. Many individual part defects can be solved by replacing that part. 

People sometimes choose to replace their unit much sooner than that 15-year time frame. This is simply because newer units are often more energy efficient than older units, and provide better performance

So, Can You Retrofit MVHR?

Hopefully, by now you understand a few more of the ins and outs surrounding this question.

MVHR is suitable for retrofit, but as always you should work with an expert to make sure it is the right choice for you.

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Why Do I Need MVHR?

Why do I Need MVHR?

Why do I Need MVHR? You may be asking yourself. We've written this article to clear up that question, and more! So kick back, relax and tuck into a healthy dose of information, to help you decide whether or not you need MVHR, and why!

What is MVHR?

Mechanical Ventilation with Heat Recovery (MVHR) is a whole home ventilation system. It works by extracting the stale, moist, and polluted air from the inside of your home or other property. It then resupplies with fresh, filtered air. 

At the same time, the air travels through a heat exchanger. This then transfers a large percentage of the heat energy from the extracted air to the incoming air, resulting in a more energy-efficient building when installed correctly.

This creates a more comfortable, condensation and mould-free environment year-round.

Read more about this in our previous article! What is MVHR?

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Building Regulations and MVHR

MVHR meets Building Regulations for new properties and retrofits under System Four of Building Regulations Part F.

Moreover, when you build a new property or retrofit an existing property, it is important you comply with building regulations. 

Part F of the Building Regulations, covers installation, inspection, testing, commissioning, and the provision of information pertaining to and installing fixed ventilation systems in your home or other property. 

Approved documents provide you with all the guidance you need on how to accurately meet these regulations.

Why Do I Need MVHR?
A Building site

The most important approved document for MVHR is Approved Document F (Part F). This document gives you guidance on how you must meet building regulations that apply directly to ventilation.

Part F states that you must provide adequate ventilation to prevent excess condensation buildup. This buildup could damage the structure of the property. It also ensures that airflow throughout your property maintains adequate levels of indoor air quality.

Every room in a property should have adequate ventilation for health reasons. Each type of room has its own ventilation requirements.

MVHR is listed as a key method of ventilating a property in Part F. Heat recovery provides fresh, filtered, clean air, while extracting stale, moist air out of the wet rooms of a home in an energy-efficient manner.

Wet rooms include kitchens, bathrooms, and utility rooms.

Trickle vents or background ventilation is not required with an MVHR system.

Why Do I Need MVHR?
A window covered in condensation

Maybe The Real Question Should Be, Why Do I Want MVHR?

New homes are becoming more airtight due to a variety of efficiency measures, like insulation, draught-proofing, and double glazing. This lack of natural ventilation allows moisture from day-to-day activities (cooking, cleaning, breathing, etc.) to build up with no means of escape. This moisture collects on cold surfaces, like windows and external walls, causing condensation which creates dampness, and mould growth which contributes to poor IAQ (Indoor Air Quality), and in addition potential damage to your property.

To summarise, MVHR systems come with many benefits, such as:

Read more about the problems caused by condensation in a previous article!

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Save Energy With MVHR

Using an MVHR heat recovery system can recover up to 90%+ of otherwise wasted heat energy. Furthermore, this recovered energy can reduce your heating requirements by up to ~25% with a well-installed system. 

Depending on where you buy, your initial investment could pay for itself within 5 years. Factors like air tightness do however come into the equation, causing this efficiency to drop, and, generally, the leakier the property the less efficient. 

An office building using a heat exchanger above 80% efficiency can save around 30% on heating bills. The cost of running a heat recovery system is usually less than 10p per day.

How Efficient Are MVHR Systems?

MVHR systems are highly efficient systems, that recycle thermal energy used in your home, reducing your carbon footprint and saving money on your bills. 

What's more, how much depends on your property and how airtight it is, the more airtight the more efficient your system will be.

Generally speaking, an older property is going to be less airtight than a newer one.

Read more about this in a previous article.

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Are There Disadvantages To Having MVHR?

Of course, as with everything, there are some disadvantages to an MVHR system, some of which are:

How Efficient Are MVHR Systems?

How Efficient Are MVHR Systems?

How efficient are Mechanical Ventilation with Heat Recovery (MVHR) systems? It is a question that seems easy to answer but has many caveats. This article should leave you with a better understanding of the relationship between airtightness and ventilation, and how improving airtightness increases the efficiency of MVHR.

How Efficient Are MVHR Systems?
How MVHR works!

What is MVHR?

MVHR is a whole home ventilation system. It works by extracting the stale, moist, and polluted air from the inside of your home or other property. It then resupplies it with fresh, filtered air. 

At the same time, the air travels through a heat exchanger. This transfers a large percentage of the heat energy from the extracted air to the incoming air, resulting in a more energy-efficient building when installed correctly.

This creates a more comfortable, condensation and mould-free environment year-round.

Read more about this in our previous article! What is MVHR?

Ready to build your system?

How airtight does a home need to be for MVHR?

The more airtight a property starts before MVHR, the better. However, this does not mean that MVHR does not benefit “leakier” properties. 

MVHR will still improve indoor air quality in a leakier property for example.

The efficiency however is much greater with an actual airtightness level of 3 m3/(hr.m2) or lower.

Generally speaking, newer, building regulation-meeting properties will be more airtight, and older buildings will be “leakier”. Renovated buildings have their own level of regulations to meet, and will generally be quite airtight.

How Efficient Are MVHR Systems?
MVHR systems can help save energy

Lowering Your Heating Bills with MVHR systems

In a previous article, we spoke about whether or not MVHR systems are worth it. In that article, we spoke a little about cost-effectiveness.

Using an MVHR heat recovery system can recover up to 90%+ of otherwise wasted heat energy. This recovered energy can reduce your heating requirements by up to ~25% with a well-installed system. 

Depending on where you buy, your initial investment could pay for itself within 5 years. Factors like air tightness do however come into the equation, causing this efficiency to drop. The leakier the property the less efficient. 

An office building using a heat exchanger above 80% efficiency can save around 30% on heating bills. The cost of running a heat recovery system is usually less than 10p per day.

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Installing MVHR in Older Buildings

Older buildings are often quite leaky, but ventilation in old buildings is still important. This may seem odd as usually, we try to make older buildings more airtight, sealing holes and gaps. While this is important to stop cold air from getting in, airtight buildings have no air circulation which can create condensation and mould. This is why mechanical ventilation is important.

It is often said that older buildings do not benefit from MVHR, however, this is not the case. It may not be as efficient as it is in newer buildings but there are still benefits, such as:

Read more about this, and installing MVHR in new builds in a previous article!

How Efficient Are MVHR Systems?
Design and Install the MVHR system early

Design and Install Early for the Best Efficiency

Whether renovating or building anew, the answer is almost always: As early as possible.

Ideally, as soon as the project receives planning permission is the best time to design the MVHR system.

Once built, a new energy-efficient build can be difficult to modify with an MVHR system. It is important to work closely with your engineer/architects to overcome issues during the design stage.

In a renovation project, always plan the renovation around the MVHR system to avoid problems with installation later.

Planning right from the start can ensure:

Read more about this in a previous article!

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Does MVHR require much maintenance?

Generally, MVHR requires little maintenance. It spends most of its life running unnoticed in the background! You won’t even touch the control very often unless you take a lot of showers, and even then you will just briefly boost the fan speed. 

The only maintenance you will need to do on most MVHR systems is a little bit of upkeep. Changing filters once a year may be required, though often you can vacuum these, and reuse them for quite some time. 

It can also be worth checking the heat exchanger for damage, which on most units will simply slide out for inspection.

So, How Efficient Are MVHR Systems?

MVHR systems are highly efficient systems, that recycle thermal energy used in your home, reducing your carbon footprint and saving money on your bills. 

How much depends on your property and how airtight it is, the more airtight the more efficient your system will be.

If you find yourself in need of a bit more guidance regarding how this applies to your property, please feel free to call and speak to one of our experts at 01636639900!

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What Causes Condensation?

What Causes Condensation?

Condensation is caused whenever warm air collides with cold surfaces, or when your home is too humid. The warm, moisture-packed air cools quickly once it comes into contact with a cold surface and releases the water, resulting in liquid droplets.

Daily Tasks that Cause Condensation

We all bathe or shower regularly, but other things we do regularly also cause condensation. Some examples are:

The average family of 4 will contribute around 4 pints of water per person each day just by doing these tasks, which equals around 100 pints of water vapour every week!  With poor ventilation, this vapour will likely turn into condensation.

Ready to build your system?

If you Insulate, you must Ventilate

In the days before loft insulation, wall insulation, or even double glazing, this vapour-filled, humid, stale air would have escaped through background ventilation. Ill-fitting doors and windows for example would have allowed this air out, and replaced it with fresher, colder air. If you have ever felt a draught, you’ve experienced this process.

In new builds or renovations that meet building regulations, however, this air cannot escape so easily. With the addition of energy-saving measures such as double glazing, cavity wall insulation and draught-proofing, there is little to no natural ventilation. This leads to a build-up of vapour-filled air being trapped in the property without the addition of proper ventilation.

What Causes Condensation?
A window showing condensation build-up

When does vapour become condensation?

Once the build-up of vapour in the air surpasses the dew point. What is a dew point I hear you ask? According to the Met Office, the dew point is the temperature at which condensation occurs. This depends on the humidity and pressure of the air. At the dew point, the amount of water vapour being condensed equals the amount of water vapour being evaporated.

Condensation occurs when excess moisture in the air exceeds the dew point. This can happen in a number of ways:

Condensation is more likely to occur when there is more moisture in the air. It is likely that you will notice this condensation first on a window, as warm humid air contact the colder surface of the window and causes water droplets to form.

Ways to Remove Condensation

Adequate ventilation is the only way of preventing condensation. 

To reduce condensation you need to reduce excess moisture in the property. 

You can of course help to prevent what causes condensation in your home in other ways, such as:

These methods will likely slow down the build-up of water vapour in the air, however, they will not remove the problem entirely. If you lead a busy lifestyle, you are likely to forget to do these things sometimes, and the British Climate makes this even more difficult.

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Problems Caused by Condensation

When this air is trapped inside, with poor ventilation, we get condensation. While this may not seem like a major problem at first glance, condensation can cause various issues.

Condensation can:

When a property becomes damp, and condensation is allowed to continue, this invites black mould. 

Black mould can cause a whole host of health problems, such as unexplained headaches, fatigue, sneezing, skin rashes and more. You may have just thought yourself prone to these things, without realising black mould had started to take hold in a damp condensation-filled corner.

Condensation can also cause visual deterioration both indoors and out, like visibly damp and mould patches on your walls, carpets and furniture.

Moisture trapped in the structure of your walls can result in corrosion of the plaster, timber rot, cladding rot and other issues, which result in costly repairs.

Finally, due to the impact of condensation on your property, your heating has to work harder to combat these issues, resulting in a higher energy bill. 

How to Prevent Condensation

As we said before Adequate ventilation is the only way of preventing condensation. 

We often overlook ventilation while insulating our homes to make them as warm as possible. However, the ever-increasing airtightness level of new homes and renovations removes the natural ventilation sources.

That is why current building regulations require you to meet certain ventilation standards.

Some ventilation types (like Mechanical Ventilation with Heat Recovery or MVHR) can even save energy by recycling usually lost heat energy back into the fresh air intake.

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When in the building process should I design my MVHR system?

When in the Building Process Should I Design My MVHR System?

When in the building process should I design my MVHR system? It is important to start designing your Mechanical Ventilation with Heat Recovery (MVHR) system at the right stage of the build process. But, at what stage of the building process should you be designing the MVHR system for your building?

What is MVHR?

MVHR is a whole home ventilation system. It works by extracting the stale, moist, and polluted air from the inside of your home or other property. It then resupplies it with fresh, filtered air. 

At the same time, the air travels through a heat exchanger. This transfers a large percentage of the heat energy from the extracted air to the incoming air, resulting in a more energy-efficient building when installed correctly.

This creates a more comfortable, condensation and mould-free environment year-round.

Read more about this in our previous article! What is MVHR?

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Is MVHR Suitable for My Property?

In a previous blog, we discussed whether or not MVHR was suitable for your property. 

Whether your property is old or new, retrofit, renovation or new build, MVHR can bring benefits. Such benefits include:

Older buildings tend to be leakier, which can reduce the heat exchanger's effectiveness. New builds are designed from the ground up to be more airtight, with high levels of insulation and little to no natural/background ventilation. The rule of thumb for MVHR is usually that the air permeability of the thermal envelope should be at 3 m3.hr/m2 @50Pa. 

When in the building process should I design my MVHR system?

At What Stage In The Building Process Should The MVHR System Be Designed For My Building?

Whether renovating or building anew, the answer is almost always: As early as possible.

Ideally, as soon as the project receives planning permission is the best time to design the MVHR system.

Once built, a new energy-efficient build can be difficult to modify with an MVHR system. It is important to work closely with your engineer/architects to overcome issues during the design stage.

In a renovation project, always plan the renovation around the MVHR system to avoid problems with installation later.

Planning right from the start can ensure:

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At what stage in the building process should the MVHR system be installed?

Again, we recommend the earlier the better. Ideally, the fabric of the building would be built with ducting in place, ready to install the unit once the building is watertight. 

Depending on the insulation types used in the build, it could be difficult to install ducting later, compromising the thermal envelope. 

Similarly, different types of ducting can allow more or less flexibility. You should install rigid ducting during the build phase. This avoids having to chop it into segments and using connectors, which involves more time, parts and effort. Semi-rigid ducting is more malleable, and could be easily installed during a build or later in a renovation. 

When in the building process should I design my MVHR system?

Work With an MVHR Expert From The Offset

Whether designing a system to retrofit into an old home or building a new office building, we recommend you always work with an MVHR expert from the offset.

You could just get help checking over your plans, and if you feel confident then why not? We however recommend that you have an expert work with you on our design. This will ensure the design doesn’t run into any issues later, like clashes with joists, or pipe work. 

They can also ensure your build meets building regulations.

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Is MVHR Suitable for My Property?

Is MVHR Suitable for My Property?

Is MVHR suitable for my property? It is common in the Mechanical Ventilation with Heat Recovery (MVHR) industry to assume that an MVHR system wouldn't benefit a “draughty” property. Draughty here means the build has an actual fabric airtightness of 3 m3/(hr.m2) or higher.

This has led to MVHR systems only being considered in more airtight new builds or retrofits.

Research undertaken by the Passivhaus Trust now shows us that this is not necessarily correct. It proves that any property with a reasonable level of fabric air permeability will benefit from MVHR. Even in a draughty home, MVHR will significantly lower CO2 emissions. So is MVHR suitable for my property?

What is MVHR?

MVHR is a whole home ventilation system. It works by extracting the stale, moist, and polluted air from the inside of your home or other property. It then resupplies it with fresh, filtered air. 

At the same time, the air travels through a heat exchanger. This transfers a large percentage of the heat energy from the extracted air to the incoming air, resulting in a more energy-efficient building when installed correctly.

This creates a more comfortable, condensation and mould-free environment year-round.

Read more about this in our previous article! What is MVHR?

Ready to build your system?

Installing MVHR in Older Buildings

Ventilation in old buildings is important. This may seem odd as usually, we try to make older buildings more airtight, sealing holes and gaps. While this is important to stop cold air from getting in, airtight buildings have no air circulation which can create condensation and mould. This is why mechanical ventilation is important.

It is often said that older buildings do not benefit from MVHR, however, this is not the case. It may not be as efficient as it is in newer buildings but there are still benefits, such as:

Improved indoor air quality (IAQ)

In areas where air quality is a problem (pollen, air pollution), an MVHR system with adequate filtering can provide cleaner air to the property. The positioning of the air intake can also matter in this case.

Lower humidity

MVHR will contribute to the reduction of humidity and condensation by providing constant ventilation. MVHR systems actively aid in dehumidification when the outside air is colder than the inside.

No need for bathroom fans or window vents

With the use of MVHR heat recovery systems, there will be no need for draughty window vents or loud bathroom fans.

Reduced noise and dust

If a property suffers from noise well installed MVHR systems with adequate insulation and silencing can provide a solution. Less opening of windows results in less noise ingress.

MVHR allows you to meet the EnerPHit standard for renovations/retrofits.

Other Factors

There are other factors to consider when renovating or retrofitting your property and installing MVHR. 

Building fabric is one of these factors. Many old buildings will have trouble hiding ducting, and in some cases trouble running ducting to downstairs rooms at all. 

Such properties can still benefit from MVHR, by removing air from upstairs wetrooms and adding fresh clean air to the living areas upstairs. 

Installing MVHR in New Builds

To meet the building regulations for new ventilation in new builds it is important to combine an airtight envelope with a high level of heating efficiency. Heat Recovery is key to achieving this goal.

MVHR is key to keeping a home healthy and comes with many benefits such as:

MVHR allows you to meet the Passivhaus standard for new builds.

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How airtight does a home need to be for MVHR?

The more airtight a property starts before MVHR, the better. However, this does not mean that MVHR does not benefit “leakier” properties. 

MVHR will still improve indoor air quality in a leakier property for example.

The efficiency however is much greater with an actual airtightness level of 3 m3/(hr.m2) or lower.

What is MHVR like to live with?

MVHR has all the benefits previously outlined, but what does that mean practically? What is MVHR like when we actually live with it?

Improved air quality means that your MVHR system filters out pollutants and particles in the air, meaning you breathe in less of the general city pollution or dust from living in the country. The lower dust level also means less housework, and no loud bathroom fans that activate whenever you switch on the lights at night.

So, Is MVHR Suitable for My Property?

Regardless of your property, the chances are MVHR will improve the energy efficiency of your property. Whether it is old or new, airtight or draughty, you could save money and have a healthier home by using MVHR.

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are mvhr systems worth it

Are MVHR Heat Recovery Systems Worth it?

Are Mechanical Ventilation with Heat Recovery (MVHR) systems worth it? It can be a tricky question. While the answer to this can vary from property to property, generally speaking, Yes! A well-installed MVHR (Mechanical Ventilation with Heat Recovery) system will offer substantial savings on your heating bills when compared to the use of normal bathroom fans and ventilating by opening windows. 

Another important thing to consider is Indoor Air Quality (IAQ). This can be dramatically improved using MVHR, improving the health and well-being of residents of, or visitors to, a property. 

What is MVHR?

MVHR is a whole home ventilation system. It works by extracting the stale, moist, and polluted air from the inside of your home or other property. It then resupplies it with fresh, filtered air. 

At the same time, the air travels through a heat exchanger. This transfers a large percentage of the heat energy from the extracted air to the incoming air, resulting in a more energy-efficient building when installed correctly.

This creates a more comfortable, condensation and mould-free environment year-round.

Read more about this in our previous article! What is MVHR?

Lowering Your Heating Bills with MVHR systems

Using an MVHR heat recovery system can recover up to 90%+ of otherwise wasted heat energy. This recovered energy can reduce your heating requirements by up to ~25% with a well-installed system. 

Depending on where you buy, your initial investment could pay for itself within 5 years. Factors like air tightness do however come into the equation, causing this efficiency to drop. The leakier the property the less efficient. 

An office building using a heat exchanger above 80% efficiency can save around 30% on heating bills. The cost of running a heat recovery system is usually less than 10p per day.

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Improving Indoor Air Quality (IAQ) Makes MVHR Systems Worth It

Over the past decade, the demand for well-insulated buildings has risen significantly. Houses that are well insulated but not also well ventilated can find themselves with poor indoor air quality.

A lack of fresh air can result in condensation, damp, mould and a build-up of dust in a property. Side effects of this include unpleasant smells and a build-up of toxic gases which can lead to health problems such as asthma and other respiratory problems.

Installing an MVHR system in your new build, or retrofit will allow you to have a constant supply of fresh air. This air will be filtered, reducing mould and condensation, while recovering otherwise lost heat energy from the extracted air.

are mvhr systems worth it

Benefits of Home Ventilation Systems (MVHR)

MVHR systems come with many benefits, such as:

are mvhr systems worth it

Things To Consider

There are many aspects to take into consideration when planning an MVHR system for your property. Some of these include:

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Installing MVHR in Old Properties

For old properties retrofitting is a possibility, however, it comes with its difficulties. Older houses are generally less airtight than newer builds, and to get the largest benefits from an MVHR heat recovery system, you need a property to be as airtight as possible. 

Older buildings are often leaky, with various background ventilation systems built in, causing them to not be particularly airtight. Many of these buildings get heavily insulated and have double glazing installed, reducing draughts and increasing air tightness. While great, this creates its own issues, such as damp, mould and condensation.

MVHR systems can help reduce or eliminate these issues.

There will be occurrences where not all rooms in an older property can have MVHR ducting run directly to them due to their construction. However, it will be possible to install it on the top floor, allowing for bedrooms and bathrooms to be condensation and mould-free.

Installing MVHR in New Houses

Installing MVHR into a new build is much simpler, and is a great investment. It will improve indoor air quality, lower your heating costs and reduce condensation. 

This will also futureproof the value of your home, as it meets Building Regulations. Yet another reason that MVHR systems are worth it.

are mvhr systems worth it

What Is The Lifespan of MVHR?

On average, the lifespan of an MVHR unit will be around 15 years. This does not however mean that the whole unit will need replacing after 15 years. Many individual part defects can be solved by replacing that part. 

People sometimes choose to replace their unit much sooner than that 15-year time frame. This is simply because newer units are often more energy efficient than older units, and provide better performance.

So after all of that, Is MVHR worth it?

Hopefully, this article has helped you decide that for yourself. We think the benefits of MVHR speak for themselves, but we don’t know your project!

In summary, for older homes, MVHR can increase efficiency greatly even if they are a little “leaky”. In new builds, MVHR will be a necessity to lower condensation and improve indoor air quality in a more air-tight environment.

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An example of a building where MVHR could be used

Rising insulation and air tightness standards are making modern homes and properties increasingly comfortable, but at a cost - the quality of indoor air is compromised. However, there is a solution: MVHR.

As buildings limit the flow of fresh air by becoming more air-tight, the need for ventilation becomes pressing. Although opening windows may seem like a quick fix, it's not always the most efficient or healthy solution. That's where MVHR comes in - a cutting-edge technology that enhances energy efficiency and provides superior air quality. But, what exactly is MVHR?

How Do MVHR Systems Work?

First, what does MVHR stand for? Mechanical Ventilation with Heat Recovery is a system that provides ventilation to your home or other property. It operates by extracting stale, humid, and polluted air from the inside and replacing it with fresh and filtered air.

MVHR systems also incorporate a heat exchanger. Heat exchangers transfer heat energy from the extracted air to the incoming fresh air resulting in a more energy-efficient property.

With MVHR, you can enjoy a comfortable indoor environment year-round. Free from issues such as condensation and mould, while improving indoor air quality. It's a practical solution to the challenge of balancing energy efficiency and air quality in modern, airtight buildings.

A diagram showing how MVHR works
A diagram showing how an MVHR unit works

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Does MVHR Comply With the UK’s Government Building Regulations?

Ensure your property meets building regulations for ventilation with the advanced technology of Mechanical Ventilation with Heat Recovery, or MVHR. Whether building from scratch or retrofitting an existing property, compliance with regulations is essential.

Building Regulations Part F covers the installation, inspection, testing, commissioning, and provision of information for fixed ventilation systems in your property. Fortunately, Approved Document F (Part F) provides clear guidance on how to comply with these regulations accurately.

According to Part F, adequate ventilation is crucial to prevent excess condensation build-up that can damage the structure of your property. It also ensures proper airflow, which helps maintain optimal indoor air quality in every room of your home.

Read more about the detrimental effects of condensation in our article What Causes Condensation?

MVHR is a key method of ventilation listed in Part F, specifically for wet rooms such as kitchens, bathrooms, and utility rooms. It provides fresh, filtered, and clean air while extracting stale and moist air in an energy-efficient manner. Best of all, with an MVHR system, there is no need for trickle vents or background ventilation, giving you peace of mind and cost savings.

MVHR is highly efficient at filtering incoming air, and with inline filters, you can rest assured that outdoor particulates like pollen will not come into your home.

Read more on this topic in our Article Does MVHR Alleviate Hayfever Symptoms?

By incorporating MVHR into your property, you can rest easy knowing that your home is not only compliant with building regulations but also equipped with cutting-edge technology that enhances your living experience.

A Diagram showing the concept of an MVHR installation
The layout of a basic MVHR install

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Why Choose MVHR?


As homeowners increasingly adopt energy-efficient measures like insulation, draught-proofing, and double-glazing, their homes become more airtight, resulting in a lack of natural ventilation. This means that moisture from daily activities such as cooking, cleaning, and breathing can build up with no way to escape.

The accumulated moisture can then settle on cold surfaces such as windows and external walls, causing condensation, dampness, mould growth, and poor indoor air quality (IAQ), which can even lead to property damage.

However, MVHR units offer a practical solution to these issues. MVHR units provide a practical solution to the issues caused by airtight homes. Unlike traditional ventilation systems, they operate continuously and remove excess moisture, reducing the risk of structural and cosmetic damage from mould and condensation.

Additionally, they recover a significant amount of heat energy that would otherwise be lost through a heat exchanger, making them a more energy-efficient option for improving IAQ and reducing associated costs.

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MVHR systems offer several advantages over background ventilation systems, such as consistent ventilation that isn't affected by factors like wind speed, obstructions, or temperature changes. This ensures that indoor air quality is optimal, unlike background ventilation systems which can be inconsistent.

Moreover, MVHR is suitable for properties with varying levels of airtightness, according to Part F of the building regulations. However, older, leakier properties may not benefit as much from MVHR's capabilities.

To ensure that airtightness levels are appropriate for your new build or retrofit project, it's advisable to consult with an architect or consultant before commencing the project. With MVHR, you can enjoy peace of mind, knowing that your property is protected against moisture damage, mould growth, and poor IAQ, while also being energy-efficient and comfortable.

Read more on this in our article Why Do I Need MVHR?

A person opening a trickle vent
Is your trickle vent open?

Additional Benefits


Opening windows may not always be practical or desirable for ventilation and indoor air quality, especially in noisy or polluted areas. To address these challenges, MVHR systems offer a solution that can reduce noise, filter incoming air, lower humidity levels, and prevent pest intrusion.

If you live in a noisy area, you may not be able to open your windows due to the noise levels. In such cases, MVHR systems with silencers can provide a practical solution by allowing for ventilation without compromising noise reduction.

In areas with poor air quality, opening windows may not be ideal for ventilation. MVHR systems can filter incoming air, removing pollutants and providing a constant flow of fresh, clean air.

MVHR systems also help to reduce humidity levels in the property. When the outside air is colder than the inside air, the system can actively dehumidify, removing excess moisture and reducing the risk of dampness and mould growth.

In areas with high levels of small insects, opening windows can lead to unwanted pests entering the property. MVHR systems with tightly fitted filters can prevent pest intrusion while providing proper ventilation.

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Sustainability and MVHR

Moreover, MVHR systems are a sustainable solution for improving indoor air quality and reducing energy consumption. By recycling heat energy that would otherwise be lost, MVHR can significantly lower heating costs and associated carbon emissions. In addition, using a ventilation system reduces the need for opening windows, which can result in energy loss and higher heating or cooling costs. MVHR is an environmentally responsible choice for modern homes and buildings, providing energy-efficient design and sustainable benefits.

Read more on this topic in our article Is MVHR Sustainable?

Disadvantages

As with everything, there are some disadvantages to an MVHR system, some of which are:

Such a system can have a high upfront cost to install, though this is somewhat offset by a reduction in heating bills in the long run.

MVHR systems rely on ducting, and as such may be difficult to hide in a retrofit or a new build with limited space.

Heat recovery systems also need maintenance, though this primarily consists of cleaning filters and heat exchangers.

Learn how to clean your filters in our article How Do You Clean MVHR Filters?

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