Air Source Heat Pumps are quickly becoming the go-to heating and hot water solution for domestic homeowners, landlords and housing associations throughout the nation, but are they suitable for every property? 

We are often asked the same questions about Air Source Heat Pumps:- Does my house have to be super insulated before I install a heat pump? Are Air Source Heat Pumps only compatible with underfloor heating or can they be used with radiators? Will an Air Source Heat Pump increase my energy bills if I switch from oil, coal or electric heaters?

Having installed hundreds upon hundreds of Air Source Heat Pumps throughout the Western Isles since 2010, it would be untrue for us to say that every house was super insulated, because of course in truth the answer to that question is no, not every house was super insulated. Did it matter? No, it didn’t. The Air Source Heat Pump still worked and still worked very efficiently compared to previous heating systems. Why? Because the system was designed and set up correctly. Systems must be sized correctly with specific parameters considered for different types of houses, with respect given to the levels of insulation present, the size of each room and the occupancy.

We would never recommend installing an Air Source Heat Pump in a house with no insulation at all, because in such a case the radiators and heat pump would have to be disproportionately large resulting in a system that would be expensive to run. That said, if this was the case, we would not be recommending any other type of heating system either, because any other type of heating system would be subject to the same abominable running costs that are tied to an uninsulated property. Insulation is therefore crucial in modern day housing no matter what age the house is and regardless of the type of heating system. The key elements of insulation that matter for an Air Source Heat Pump are loft/roof insulation, wall insulation, windows and external doors. It is not common for us to see underfloor insulation, and most Air Source Heat Pumps will be retro fitted in older housing that does not have underfloor insulation because of the difficulties and challenges associated with insulating floors. So long as a house has at least 200mm of loft insulation, 50-100mm insulation in the walls and double glazed windows & doors then we will usually have no hesitation in recommending Air Source Heat Pumps. If you have a double block cavity build house, then cavity insulation is a bonus that is not always necessary. We have fitted Air Source Heat Pumps in houses with double block open cavities on many occasions with no issues, because we have taken these parameters into account when sizing the heat pump and radiators.

Let’s face it, Air Source Heat Pumps nowadays are 350% efficient so you are getting an extra 250% of renewable energy for free for every 100% of energy you are spending. There is no solution that rivals an Air Source Heat Pump for affordability, feasibility and efficiency. Those who say they don’t work with radiators are completely misled. The vast majority of Air Source heating and hot water systems are installed with radiators because underfloor heating is more expensive to install. Radiators can be run with a 45, 50 or 55 degree flow temperature depending on the circumstances of the property. Obviously the lower the flow temperature the cheaper it will be to run and the larger the radiators will be, so careful consideration should be given to every aspect of a proposed installation at the design stage. 

But will it really be cheaper than my current oil boiler, electric heaters, or solid fuel coal back boiler? The short answer is yes. The long term answer is an inevitable yes. Do you want to get ahead of the game and act now or wait until fluctuating energy prices put you on the back foot again? There are interest free loans with cash back grants available for domestic home owners from Home Energy Scotland. Other fully funded avenues are available for people claiming benefits including Child Benefit, Universal Credit, Income Credits and the Pension Credit. Get in touch with us if you would like to discuss anything further.

Steven Murray
Director