Why is everyone talking about heat pumps and are they the future? - 91

With the planet warming and the consequences of climate change evident across the globe, governments are at last taking more definite action to reduce fossil fuel emissions in an effort to restrict global warming to a minimum of 1.5 degrees. But what has this got to do with heat pumps? The answer is that this technology  is a key component in making buildings, and dwellings in particular, more environmentally sustainable.

The effort against climate change is growing. A large proportion of the general public are perhaps now aware that the burning of fossil fuels, be it gas, oil or coal, to heat our houses are very bad in terms of Co2 emissions (especially coal) and it is government policy to have their use phased out. The move to electric cars is an example of this happening in the transport industry.

The good news when it comes to heat pumps the appliance may be powered  by energy from carbon neutral sources such as solar panels, wind, hydroelectricity and even nuclear power generation.

But perhaps best of all, heat pumps offer what some may consider  a magical property -  one big reason behind their popularity - when we put one unit of energy in, we get at least 2.5 units of energy out in the form of heat. This makes the use of electricity as a primary heating source almost as competitive as gas or oil. If governments were to put a small carbon tax upon oil or gas then it would be cheaper and greener to use a heat pump to heat your home. Furthermore, an air-source heat pump is a tried and tested technology which is relatively easy to install. Our architectural practice have been installing air-source heat pumps for many years in ultralow energy Passivhaus standard homes. The feedback from our clients has been very positive, one mentioning they had not touched their heating controls in two years and were very happy with the size of their energy bill, which was solely electric.

These are all the up-sides of heat pumps. But before you rush out and scrap your old oil burner you must know that, like all things, there are caveats as to when this technology is appropriate.

The first issue to bear in mind is that heat pumps are more efficient at lower temperatures like  40 degrees centigrade. This is an ideal temperature for underfloor heating and heating water for washing, etc. It is not the temperature generated by gas or oil burners, which typically run at 60 degrees or more. This means that you cannot easily replace an oil/gas burner with a heat pump, (known as retrofitting), without making modifications – so switching to this green technology can sometimes be more tricky .

The second potential issue with heat pump technology relates to  the size of the house and the actual electricity supply needed for a large heat pump appliance. In some instances, a costly infrastructure upgrade may be needed.

However, if we build energy efficient homes to a high standard, then our experience tells us that heat pumps work extremely well as a heating source, and if you are fortunate enough to be able to combine this with your own green sources of energy, such as Solar Photovoltaic  panels, you can reduce you homes carbon footprint to almost nothing.

Paul McAlister is the Managing Director of Paul McAlister Architects & Energy Consultants, based in Portadown. Visit pmarchitects.com.