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Originally Posted On: https://www.renewableheatingwales.co.uk/2023/04/24/what-is-mvhr/
MHVR, or mechanical ventilation with heat recovery, is a contemporary building ventilation system that can be used to improve airflow and ventilation throughout a property. In the wake of the Covid-19 pandemic, the benefits of improved ventilation are well-known, and MHVR may offer a solution to commercial and residential property owners for whom ‘opening doors and windows’ isn’t enough.
Not only is MHVR better at ventilating a property than traditional methods like this, but it’s also more efficient and less wasteful.
What is MVHR?
MVHR stands for mechanical ventilation with heat recovery. It’s a type of ventilation system that not only ventilates your home or building but also keeps the air at a comfortable temperature. Without MVHR, the only way most property owners can ventilate their properties is by opening doors and windows. Not only is this not actually a very efficient way to ventilate a property, but it also leads to rapid heat loss, especially in cooler temperatures.
Switching to MVHR ventilation systems can help property owners to manage all aspects of the air quality within a building using a single system. An effective MVHR system can help you to control air tightness, moisture levels, temperature, humidity and ventilation simultaneously. It’s a highly efficient system that can also save you money on your energy bills and reduce your carbon footprint when compared to using a combination of other methods – like traditional heating and opening windows – to achieve similar outcomes.
How MVHR works
MVHR systems work by extracting moist, stale and polluted air from wet rooms within a property like bathrooms, kitchens, and laundry rooms. This stale air then passes over a heat exchange cell to recover the heat from the air. The MVHR then transfers this heat to fresh, filtered air that is supplied into areas around the home including bedrooms, living rooms, and hallways. Effectively, an MVHR filters the air around your home without causing heat loss to keep your air clean and your home at a comfortable temperature.
An MVHR installation
As well as cleaning the air around your home, the additional heat recovery work of an MVHR system reduces the heating and cooling requirements of your home or commercial building and maximises heating and cooling efficiency. Because MVHR systems constantly work to ventilate a property and heat fresh air, they don’t allow enough time for the moisture to settle on surfaces and cause damage or encourage mould growth inside a property. They are an incredibly effective way to ventilate a property with minimal energy waste.
Pros and cons of MVHR
There are advantages and disadvantages to installing an MVHR system in your home or commercial property. These systems are effective at what they do, but they’re not suitable for everyone due to the cost of installation as well as space requirements that most MVHR systems have. Let’s take a look at some of the pros and cons of mechanical ventilation with heat recovery systems.
Pros
An efficient way to improve air quality
Provides a constant supply of fresh, filtered air
Can be installed in new and older properties
Reduces heating costs
Lowers humidity and condensation
Energy-efficient
Recovers normally lost heat
Cons
Requires small amounts of maintenance, such as changing the filter every 6-12 months
May include upfront costs for the installation
Must be appropriately installed around log burners and stoves
Requires enough space for the installation of the unit and ducting runs
Overall, if you can afford the upfront costs and you have the space for an MVHR, they offer many benefits that could save you money in the long run while improving comfort levels throughout your home.
Types of MVHR
If you’re considering installing an MVHR system in your home, it’s important to understand the difference between two of the most common types of MVHR on the market: whole-house heat recovery and single-room heat recovery MVHR.
Whole house heat recovery systems: A whole house heat recovery system is usually installed within a loft space with ducts providing filtered, heated air to rooms throughout the property.
Single room heat recovery systems: Single room heat recovery systems are installed through outside walls, and they supply filtered air from outside into each room from which they extract stale air. Single-room systems are efficient and superior alternatives to inefficient extractor fans.
Whole-house systems are often more efficient to install if you want to ventilate an entire house, but single-room systems can achieve the same effect as whole-house systems if they’re installed in multiple rooms throughout the property.
When to use MVHR
MHVR is a great option for property owners who want to reduce their energy bills and improve indoor air quality at the same time. This results in a healthier and more comfortable living space all year round without accruing significant running costs to the owner of the building. MVHR is most appropriate for:
Brand new properties that can be designed to accommodate MVHR systems easily
Properties in noisy areas where opening windows for ventilation isn’t practical
Homes with sufficient airtightness to ensure that an MVHR system is effective, usually at least 5m³/hr/m²
Enough ceiling height and space to install the unit and the ventilation ducts
Making sure that your property is suitable for an MVHR system before you book an installation is key. Professional MVHR installers should be able to advise you on the suitability of your property for an MVHR system as well as any potential complications that could arise during installation.
A summary of MVHR systems
In summary, MVHR systems are efficient and effective contemporary systems that can help property owners to ventilate their properties, manage air quality, and prevent heat loss.
However, before committing to an MVHR system, property owners should check that they have the space and budget to install an MVHR. It’s likely that MVHR systems will become more commonplace in homes throughout the UK over the coming years as people look to switch to more energy-efficient methods to manage heating and air quality in their homes.
