Exothermic Installations Ltd providing professional installation and maintenance of air source and ground source heat pumps in the Swindon, Newbury and surrounding areas
What types of heat pump are there?
There are basically 3 types of Heat Pump; Ground source, Air source and Water source. Their name denotes where the energy to provide the heat comes from. The two most common are the air and ground source units, with air being the most common.
A heat pump uses the same tried and tested technology as your household fridge, only the principle is reversed. Where a fridge takes relative heat from inside the fridge, thus cooling it and dispels the heat via fins at the rear of the fridge. If you reversed the cycle, ice would form on the fins as the air is cooled as its relative heat is extracted. It would then warm the space inside of the fridge. This is exactly how an Air Source heat pump works to heat a house, where the heat produced is circulated via conventional pipework to heat the hot water and heating - either radiators or underfloor heating.
How efficient is a Heat pump?
All heat pumps are incredibly efficient heat producers, for every 1 kilowatt of electrical energy used to power the compressor, they can provide 3 to 4 kilowatts of heat. This makes them 300 - 400% efficient. This is described as their co-efficient of performance or COP. The COP or efficiency varies with heat energy input to the Heat pump and the energy output required to be produced by the heat pump - input versus output - which will vary with the seasons for all heat pumps. The required heat emitter flow temperature and the available Input temperature will effect the COP of the heat pump.
Put simply - If the free Air or ground temperature (input energy) drops so does the output energy. But this would mean your house would get colder, so the heat pump compressor has to work harder (using more electrical energy), therefore it is less efficient - or its COP is reduced. Conversely if you increase the free Air or ground temperature (input energy) you decrease the compressor workload making it more efficient - or you increase its COP. Without trying to sound confusing - if you kept the free input energy constant, but increase or decrease the output flow temperature to the heat emitters, this also effects the units efficiency or COP. But what if you vary both? Thats best explained by the chart below.
What about low temperature heating?
It is for this reason that its critical that heat pumps are correctly sized to match the heat load requirement at the minimum input temperature. For best design purposes they must be able to provide 100% heating load for 99% of the season, without additional back up input (usually provided by an internal immersion heater). They must also be designed in conjunction with the MCS heat emitter guide which gives a 6 star rating methodology, with 6 stars (lowest temperature) being the best. A 6 star system will ensure the best Seasonal performance/SCOP of the Heat pump. If they are not designed and installed correctly there will be expensive problems, such as - large and unnecessary running costs, insufficient heating of hot water or the property. Ground heave, caused by excessive cooling of earth surrounding the collector pipework on ground source units to name a few.
What do they cost to install?
The average domestic air source retrofit installation when replacing a traditional oil boiler installation costs approximately £8,000 - £16,000 installed. Costs are affected by type and size of heat pump chosen, location of equipment and the condition of the existing plumbing, heating and electrical system - which is the biggest variable. Ground source units will cost an additional £5000 + depending upon the ground works required or the bore hole drilling as well as the additional labour and materials for the ground collector pipework. Ground source units tend to have higher seasonal COPs as the input temperature from the ground is more constant .
Heat pumps will provide all of the households heat and hot water requirement reducing CO2 emissions by about 50% compared to Oil. This reduces household fuel costs and cuts carbon emissions, saving money and the environment. It can give a property a higher score on its energy performance rating and help achieve a higher level on the code for sustainable homes usually scoring level 3 on new build properties. Please note, that while you have permitted development rights, you may still require planning permission. Contact your local Authority for more advise.
Fully Qualified and Experienced Heat Pump Installers
Heat Pump systems are deemed a "a controlled service" in the building regulations (law) and as such can only be legally fitted by those who are legally competent and registered to be able to certify and notify the installation. For more information on this please visit our Competency page
Call us today to find out more about how we can help you with your heat pump installation or maintenance.