MVHR, or Mechanical Ventilation with Heat Recovery, is a system which provides fresh and filtered air for a building, such as a home or commercial property, whilst retaining virtually all the energy that has already been burned to heat the building up in the first place. MVHR is by far the best solution for highly energy efficient buildings.
When an MVHR unit is properly fitted into a house or commercial property, it provides a steady and constant supply of fresh and filtered air which maintains air quality without it being impractical. Simply put, MVHR works by taking air from polluted areas such as a kitchen or utility room and then provides fresh air to other living rooms such as bedrooms and studies.
The air taken from these polluted rooms is sent through a heat exchanger and back out into the living rooms.
#1: When Does MVHR Become Worthwhile?
An MVHR isn’t suitable for all buildings. Although they can be easily installed anywhere, there is a general rule that their use isn’t going to be worth it unless a building has a certain level of air tightness already. Although an MVHR is designed for energy efficiency, buildings should already have a degree of energy efficiency in order for their use to be worthwhile.
If a building has poor insulation, for example, then an MVHR is going to be unsuitable. Similarly, if there is no temperature gradient between the inside and outside of a building, then there is no way the unit can recover energy.
Finding out whether your building is suitable is the logical first step.
#2: How to Choose an MVHR Unit
There’s a lot when it comes to choosing an MVHR and it requires careful thought. Not only do you need to consider its performance, output and size, but you need to think about how controllable a unit is, and the type of heat exchanger which is going to be used.
It’s not possible for one manufacturer or provider of MVHR units to have a solution for all buildings. There are many different ones available and you should always be consulting an expert before making a buying decision.
#3: Look for a Good Energy Performance Rating
One factor which can help you in determining whether an MVHR is going to be any good is its energy performance rating, and since the start of 2018, all MVHR units have these displayed on them. It is always recommended that you go for an MVHR which has an A rating (bright green) as these have the best performance in terms of efficiency.
It’s quite rare that you will see an MVHR with a rating below a B, and those should always be avoided. Energy efficiency ratings are awarded by independent bodies, so you don’t need to worry about any bias; the same formula is applied to all products.
An MVHR unit is a great choice for anybody who wants to make further savings to an already energy efficient building.