Viability and economics

The most common heating systems to date have been gas or oil boilers with radiator systems. These have been economic to both install and operate – hence their popularity.

Heat pumps are one option for potentially reducing the carbon footprint of a building. However, there has been a learning-curve relating to the successful deployment of this technology. The energy-efficiency of a heat pump system can vary greatly, and is affected by the many parts of the entire system. Thankfully, the vast majority of installations now do meet up to their performance expectation.

Do heat pumps work?

This may seem an odd question, but there is no shortage of misinformation and distorted claims, so it may be no wonder that this question might be posed.

Rest assured that there are hundreds of thousands of heat pump systems operating very successfully. However, some of the earlier installations delivered poor results due to unfamiliarity with the particular requirements of heat pumps,

Historically, the conventional way of heating buildings has always involved the burning of a solid fuel (wood or coal). During the last century oil, gas and electricity have also played their part. It was not until the oil crisis of the ’70s that we started to think of ways of reducing our reliance and over-consumption of energy, as it was realised that fossil fuels were not an infinite resource. Another issue that has currently become a major concern is the fact that the burning of these fuels on such a vast scale is almost certainly affecting the global climate. Whilst there are differing views on the causes of climate change, it is universally agreed that the increased CO2 levels that are being recorded are a bad thing.

There has been a very slow adoption of renewables from solar, wind etc. but these technologies have only relatively recently become more developed and hence more affordable.

Heat pumps are not a true renewable as they require an energy input, this seldom comes from a truly renewable source since heat pumps are usually powered by a mains electricity supply. However, the total heat energy output is several times that of the power input, so a large proportion of the available heat is derived from the renewable source outside. Even when the inefficiencies of power stations are considered, the overall picture can be advantageous. Therefore they are often referred to as renewable and have become a major player in the quest to reduce CO2 emissions.

I do not assume here that if you sign up for a renewable electricty supply, that you are carbon-neutral.  It would be impossible for us all to do this, so while you might have ‘green’ electricty, you are relying on your neighbours being signed up to a normal tariff.  That said, it must surely be worth using a ‘green’ tariff if possible. e.g. Ecotricity or GoodEnergy

To assess the viability of a heat pump system we need to evaluate the actual efficiency of the heat pump system (which can vary greatly) and compare it to the running costs of heating with other fuels. We then need to evaluate this against the capital cost of the system. It should be noted that a heat pump’s working lifetime should significantly exceed that of a boiler, this is due to its inherent internal cleanliness, and low working temperatures.   There should also be a saving over servicing costs compared to boiler systems.