Why do I need Mechanical Ventilation with Heat Recovery (MVHR)?
We added MVHR to our list of services several years ago because it is very complementary to the other carbon saving and energy efficient technologies we install. These systems are very beneficial in ‘eco’ new build projects. If you are building to keep heat losses to a minimum it is important to allow fresh air into the building – but in a controlled way.
We found that many self-build customers understood the ‘sealing up’ side of their project but had not considered ventilation – they risked problems with condensation, mould, overheating and a stuffy environment. The opposite of what you want when you are creating your dream house!
This is another area where our in-house Design Department comes into its own. We can design an MVHR system alongside your heating system to optimally meet the demands for air changes in your property.
If you are not sure if Mechanical Ventilation Heat Recovery is right for your project – simply ask us the question!
Frequently asked questions about Mechanical Ventilation Heat Recovery
How does MVHR work?
MVHR works by extracting stale, moisture-laden air from rooms like kitchens, bathrooms, and utility spaces, and then passing it through a heat exchanger. At the same time, fresh air is drawn in from outside and is also passed through the heat exchanger. The heat exchanger transfers the heat from the outgoing air to the incoming fresh air, which helps to pre-warm the incoming air during colder months. In warmer months, the process can be reversed, where the incoming air is pre-cooled by the outgoing air.
How much does MVHR cost to run?
It costs approximately £30 – £55 per year in electricity to run a large MVHR system constantly, but you save a lot more than that on heating bills because it is recovering the heat that would normally be exhausted by traditional extractor fans and draughts from trickle vent windows etc.
Can I retrofit MVHR?
Fitting MVHR systems into existing properties is challenging, for a couple of reasons: –
The fabric of the building needs to be virtually airtight – hence windows often must be replaced/upgraded, trickle vents removed.
You will need to route 75 or 90mm ducting to every room of the property back to the location of the main unit.
Having said that if you’re determined it can be done. It is easier to retrofit MVHR into a bungalow. We can advise you as to whether it is possible to retrofit your property.
Where is the MVHR unit and system installed?
The MVHR unit can be installed in a large cupboard or possibly the loft space. From the unit there will be 75mm and 90mm ductwork travelling to all the rooms in the property.
There are also 2 larger 160-180mm pipes that need to go outside through a wall or roof vent, providing incoming and outgoing air.
Is a MVHR system noisy?
A properly designed MVHR system should be very quiet in its operation with air flows calculated to move the correct volume of air for each room without causing a whistling or noises pertaining to the movement of the air.
What makes of MVHR do you supply and install?
We offer both Zehnder and Vent Axia products. Both manufacturers are leading MVHR suppliers that each have their own qualities and warranties.