The complete guide to MVHR (Mechanical Ventilation with Heat Recovery) Systems

Thanks to stricter standards for insulation, buildings are becoming more energy-efficient than ever before. This is great for both you and the planet because you use less energy, your utility bills are lowered, and your carbon footprint is reduced. However, this has also led to an increased demand for Mechanical Ventilation with Heat Recovery systems, also known as MVHR systems. Why? Let us explain.

As buildings become more airtight, the more pronounced ventilation issues become; this can lead to a wealth of problems, such as condensation mould, and mildew. Ventilation methods like trickle vents and open windows can be used to address this, but these can compromise the energy efficiency of your building by letting heat escape.

MVHR systems are designed to combat this problem. So, what is an MVHR system? Meridian Cooling is the South’s climate control expert, specialising in air conditioning, refrigeration, and ventilation. In this guide, we explain everything you need to know about MVHR systems, from what they are to how they work and whether it’s worth investing in one.

What is a MVHR System?

Put simply, there are two types of ventilation: ‘natural’ and ‘mechanical’.

Natural ventilation involves utilising pressure differences from one part of the building to another, such as opening vents and windows. Mechanical ventilation uses fans to exchange outdoor air with indoor air.

But this doesn’t completely explain what MVHR systems are.

As the name suggests, MVHR systems are a mechanical method of ventilation. An MVHR unit is installed inside the building, usually within the loft or in a cupboard, along with ducting and grilles leading to select rooms. When switched on, these systems will extract stale, contaminated air and supply fresh air in its place.

What do MVHR systems do?

The main purpose of MVHR systems is to ventilate your property while retaining as much heat as possible. Ventilation systems, such as the MVHR ones, are important for a number of reasons, including:

• Removing contaminants like dust, bacteria, and smoke that could cause health problems when breathed in
• Eliminating bad odours
• Extracting excess moisture that could lead to damp and mould in your walls, ceiling, floor, or furniture
• Regulating temperature

MVHRs perform all of these functions without removing heat alongside moisture and contaminants. This means you can use an MVHR system in the winter without worrying about losing the heat in your building.

How do MVHR systems work?

While it might sound a bit complicated, the process used by these systems is actually quite simple.

Here’s how MVHR systems work, step-by-step:

• The unit draws in fresh air from outside the building and filters out dirt, pollutants, and insects.
• Stale or humid air is drawn out from moisture-dense rooms like bathrooms and kitchens.
• The two airflows pass through a heat exchanger.
• Heat is transferred from the extracted air from the room to the filtered air from outside, preventing the heat from being ventilated along with the stale air.
• Living areas within the building are supplied with warm, clean air.