Exhaust air heat pumps are a very efficient way of providing heating and hot water in new build properties. They use a specialised heat pump to extract energy from the warm air inside the property, then transfer this energy to either the ventilation system or domestic hot water supply. This makes them particularly well suited to high density housing such as apartment buildings or commercial office space.

The e-VEN 3.5kW and 5kW exhaust air heat pump from Unitherm are very efficient units that can handle ventilation through their duct connection as well as provide domestic hot water and space heating. With a COP of over 500%, they save a huge amount of energy compared with traditional central heating systems and gas boilers.

They can also help meet Code For Sustainable Homes renewable energy and building regulations ventilation requirements. They can even be used to satisfy local authority fuel poverty regulations.

A key aspect to a good heat pump performance is the efficiency of the heat exchanger. Unitherm’s e-VEN uses a patented innovative technology that reduces the energy penalty of the heat pump by increasing the condensation temperature of the refrigerant, which in turn increases the COP of the heat pump. This enables the EAHP to operate at a much lower overall power consumption than a standard outdoor air heat pump (OAHP), while delivering similar heating and cooling performance.

Another key area that is improved by the EAHP is advanced air distribution, which can further increase the COP of the unit by up to 36%. This is achieved by reusing the heat from the ventilation system to reduce the condensation temperature of the evaporator, and by preheating the ventilation system service water.

An example of this is a project in which a heat recovery ventilator was combined with an EAHP to provide a high level of energy savings for the residents of a block of apartments. The OAHP and EAHP were combined to provide cooling, hot water, and ventilation, with the EAHP supplying a large proportion of the domestic hot water load, at a COP of 4.2.

To take advantage of the benefits of an EAHP, it is important to choose an MCS approved installer. This will ensure that the equipment meets quality standards and that the installers you choose are competent and safe. We recommend that you request quotes from at least three installers, and compare prices and levels of experience before making a decision. A reliable MCS installer will also be able to advise you on the most suitable energy solution for your home. If you require further information on a particular product or would like a free, no obligation survey of your property, please contact us.