Exhaust Air Heat Pumps: Beware The Differences

Exhaust air heat pumps (EAHPs) differ widely in how they work, how they perform and where they are suitable. Here are some key performance requirements to consider when specifying:

• Energy usage / EPC ratings: As the efficiency of the products varies significantly, so does the resultant resident energy cost and EPC rating. You should be ensuring that the product achieves your minimum EPC rating (often ‘B’).
• Overheating compliance: Where there are acoustic &/or security constraints, an element of cooling will be required – not all products provide this, so make sure to understand your kW cooling requirements.
• Heat/cooling delivery medium: if you need cooling, then standard radiators or underfloor heating will not work. Some EAHPs use a forced-air system. Others will require fan coil units or convecting radiators. Make sure to consider the capital and operational costs of these.
• Air supply: Some have ducted supplies from outside (higher cost, but less susceptible to incorrect resident usage), whereas others rely on open vents through the wall, which, if closed, will cause the system to malfunction, increasing energy usage and reducing energy supply.
• Product support: Consider which suppliers can provide suitable support to residents during and after warranty periods. Currently this area is generally far behind the support available for other heating strategies.