MVHR – Mechanical Ventilation Heat Recovery – what is it and why do I need it? MVHR is one of the first things that I see as an absolute must for my new home. In simple terms, it filters the outside air, bringing it inside and expels the stale, damp air from inside therefore creating a healthier environment. In the grand scheme of things, the benefits of it far outweigh the cost and in the long term, when paired with an air tight building, it can actually save on heating costs.
How does MVHR work?
MVHR constantly pumps in fresh, filtered air. It’s pretty quiet, certainly less noisy than a regular bathroom extractor. It will draw in external air, filter it and pump it around the house. At the same time, it will extract moist, warm air from places such as the kitchen and bathrooms and push that outside of the house. Before it expels it though, it takes heat from it and uses it to warm the air that’s brought in. In the summer, you can have a summer bypass so that hot air is expelled.
Benefits of MVHR
Better air quality – The ventilation unit filters the incoming air to remove pollutants and insects and provides constant clean, warm, fresh filtered air throughout the home.
Lower humidity and no condensation – Moist, stale air is extracted from rooms such as bathrooms, kitchens and utility rooms and clean fresh air is drawn in therefore far reducing the risk of mould! Read here about how toxic mould can be!
Lower heating costs – The heat from the extracted air is transferred to the fresh incoming air via a heat exchanger within the ventilation unit. As a result, the air coming into the home has already been partially warmed and can off-set heating costs and fuel bills.
No extractor fans needed – Instead, there are vents in rooms. Some people say they notice the noise but I think this is something you get used to, I don’t really notice it when I visit homes with MVHR – it’s so quiet!
MVHR can be retrofitted although it’s definitely easier earlier on in a project. If you’re unable to have MVHR, please don’t ever turn off your extractor fans in bathrooms! I’ve seen the mould that has built up by people doing this…it’s not for smells, it’s for damp! See more about Mould Testing here.