Air source heat pumps can be used in many applications for heating water, be it domestic (tap) water or the water used in for space heating.

The first part of the decision process of whether I should consider using an air source heat pump to heat my house starts with – "why I am doing this?".

Heating System

There are of course a multitude of reasons one might consider a heat pump: your existing heating system is on its last legs; you want your next heating system to be more environmentally friendly; or you currently use a heating system where fuel cost are prohibitive and so you are on a quest to find a cheaper running cost option.

Running costs

If you are looking to replace a modern condensing gas boiler then the payback period will probably not encourage you to make the switch to a heat pump. If, however, it is any other fuel type, (with the exception of free biomass of course!) there may be considerable running cost savings to be made.

The most obvious savings can be seen when comparing heat pumps to direct electric heating or storage heaters where the 3 to 1 coefficient of Performance (COP) provides the obvious economies (see my previous blog, An introduction to air source heat pumps).

It is, however, probably fair to say that compared with all other traditional fuel heating technologies (with the exception of mains gas and free biomass) considerable running cost savings can be made. This is in addition to the ease and convenience of use of heat pumps.

Air source heat pumps can be controlled like a gas fired heating system with programmable timers and room thermostats or thermostatic radiator valves. It beats having to stoke up the fire or having to store heat the previous day because it was cold and then having to allow it to escape by opening the windows the following day in this wonderful changeable climate we have in the UK.

Carbon savings

If the reason you’re looking to replace your existing heating system is to reduce your carbon footprint to help protect your grandchildren’s future environment, then heat pumps stack up well against most traditional heating technologies. Savings of over 1 tonne of CO2 per dwelling per year can be made even against mains gas systems, perhaps the cleanest of all of the traditional fuel technologies. As our national grid becomes cleaner then this figure will only improve.

Caveat

Life is never simple of course. There are some issues that prevent an air source heat pump being your best option even if you are not in a mains gas area and I will discuss these in my next blog “Where you can use air source heat pumps".

Picture by Andrew Magill

About the author: John Lightfoot is director at Thermal Energy Ventures Ltd.

If you have a question about anything in the above blog, please ask it in the comments section below.