Retrofitting Air Source Heat Pumps Overcoming the Hurdles

Air Source Heat Pumps (ASHPs) often struggle to perform efficiently when fitted retrospectively to older properties due to several key factors. First, many older homes have inadequate insulation, which allows heat to escape quickly, forcing the Air Source Heat Pump to work harder to maintain a comfortable temperature. This increases energy consumption and reduces efficiency. Additionally, older properties tend to have single-glazed windows or outdated double glazing, which further exacerbates heat loss and makes it difficult for the heat pump to effectively retain warmth.

Another challenge is the existing heating system. Older homes typically have high-temperature radiators or boilers that are designed for conventional systems. ASHPs, however, work most efficiently with low-temperature heating systems, such as underfloor heating or larger, lower-temperature radiators. Incompatibility between the existing pipework and the low-temperature output of an ASHP means the system may not be able to provide adequate heat, forcing it to run longer or at higher energy levels, reducing overall efficiency.

Lastly, the thermal mass of older buildings, which stores heat, can interfere with the way ASHPs operate. Combined, these issues lead to higher running costs and less effective heating, making ASHPs less suitable for older properties without significant upgrades.