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Ventilation is vital

A constant supply of fresh air in the homes and buildings in which we spend more that 70% of our time is vital to our health. Energy conservation demands have meant that both new and refurbished buildings have become increasingly air tight, thereby making the provision of effective ventilation an essential element for today’s homes. Zehnder Comfosystems comfort ventilation ensures the perfect level of ventilation is achieved and that the air which we breathe whilst indoors is continuously replaced.

How a whole house heat recovery ventilation system works

1. Fresh outside air is drawn into the system via one of two methods

a. Through an external wall grille

b. After being pre-cooled or pretempered by the earth via a ground source heat exchanger

2. The Zehnder Comfosystems ComfoAir unit is continuously extracting moist and stale air from the dwelling’s wet rooms (kitchen and bathrooms). This extract air is passed over the unit’s heat exchanger where up to 90% of the heat which would otherwise have been exhausted to the atmosphere is recovered. The recovered heat is then used to pre-temper incoming, fresh outside air which can be additionally humidified, dehumidified, heated or cooled depending on the options chosen.

3. Fresh outside air is then delivered as supply air to habitable rooms around the house via an air distribution network. The volume of extract and supply air is adjusted on a room by room basis to conform to Building Regulations and to create a balanced system.


  •  Constant supply or fresh, tempered air

  • Energy savings against traditional ventilation with heat recovery

  • Promotes good indoor air quality for occupants

  • Reduces risk of mould and mildew formation

  • Requires only two holes in the fabric of the building (one for exhaust of extract air and one for incoming supply air), thus reducing noise ingress

How heat recovery works

The ComfoAir heat recovery ventilation system works to extract air from wet rooms (kitchens and bathrooms) around the clock.

It extracts the heat energy which would otherwise have been lost during the extract process and transfers this to the fresh, filtered supply air which is being drawn in from the outside.

This is done using efficient counter flow heat exchangers and can recover up to 90% of heat which would otherwise have been exhausted to atmosphere.

The right solution

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How the system works

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