Heat Recovery Ventilation (MVHR)

A heat recovery ventilation system works by extracting moist and stale air from wet rooms in your home, it recovers the usually lost heat from the extracted air. It also supplies clean, filtered fresh air that is heated from the recovered warmth of the extracted heat.

Heat recovery ventilation, also known as mechanical ventilation heat recovery, is an energy recovery ventilation system which works between two sources at different temperatures. Heat recovery is a method which is increasingly used to reduce the heating and cooling demands of buildings.

A Mechanical Heat Recovery Ventilation (MVHR) is a system that works to extract excess moisture in the air yet also recovers the heat, meaning that it provides your home with ventilated air but doesn't take out any necessary warmth. 

A MVHR unit can make your home more energy efficient when installed correctly, extracting moisture caused by condensation which can be especially prevalent in wet rooms like bathrooms and kitchens. All of our MVHR products are manufactured here in the UK and offer a wide range of innovative benefits in addition to exceptional performance and low maintenance. 

It can be difficult to know which is the best heat recovery ventilation system for your property which is why we offer a free home survey, to asses your ventilation needs and advise on the best option. 

MVHR or Mechanical Ventilation with Heat Recovery, recovers heat at ceiling level from the wet rooms (bathroom, ensuite, kitchen, utility room) and stores it in a high-efficiency heat exchange cell. It then re-distributes this filtered and tempered air into the habitable rooms, however it should not be used as a source of heating the home.

MVHR recovers heat at ceiling level from wet rooms, stores this heat and re-distributes to habitable rooms such as living rooms and bedrooms. 

When this recovered heat is not needed ie in the summer, the supply air will be diverted around the heat cell. 

MVHR offers a completely balanced system, providing both extract and supply ventilation. It extracts heat and moisture from wet rooms/kitchens and supplies fresh, filtered air, including recovered heat, to habitable rooms. MEV is also a whole house ventilation system but provides just extract ventilation from wet rooms and kitchens.

Both MEV and MVHR systems are most suitable for new properties rather than retrofit, but MVHR systems do require a more airtight property where virtually all of the air flow can pass through the heat exchanger, if they are to perform efficiently.

With inner cities obviously having higher pollution levels, MVHR systems are seen as more suitable because of the filter element, but in apartment blocks it’s often the case that only the first four floors are fitted with MVHR and the remaining with MEV as polluted air is heavier and therefore stays closer to the ground.

Put simply, a heat exchanger is a device which transfers heat from one medium to another. 

MVHR Systems provide controlled ventilation with slow but constant air movements. In contrast, natural ventilation through background ventilators (trickle vents) is a form of uncontrolled ventilation, which fluctuates with wind speeds, temperatures, internal obstructions, such as the opening or closure of internal doors, trickle vents, blinds and curtains. Therefore it is recommended to install such systems only in properties with relatively good air tightness. We recommend an airtightness of at least 5 m3/(m2*h) at the pressure test (q50), ideally below 3 m3/(m2*h). Air tightness targets should always be set for new built and refurbishment properties.