Case Study
Air Source Heat Pump Installation Lifton, Devon
Architect Fred Reeve fully understands the need to design buildings to ensure that they can be run efficiently. Having spent some two years designing his new home in Lifton, Devon, he wanted this build to incorporate features that would reduce the cost and use of fossil fuels.
The house, a three bedroomed detached bungalow, has a floor space exceeding 200 sq metres, the construction is of traditional methods and walls have been built with a 200mm cavity, instead of the usual 100mm using wool insulation as a filling. The loft is also heavily insulated with 400mm thick material.
In regard to heating this new build Fred had limited choices. As there is no gas in the village where he lives, he decided that the choice of LPG or Oil were too expensive and likely to increase in cost each year. This left electric heating as Fred is of the opinion that anything with a flue would introduce heat losses to the building because it would need to have vents.
The choice of using a heat pump had always been high on the priority list, however the initial choice of using a ground source heat pump was excluded due to the lack of outside space for installing a collector and the expense of having a borehole drilled. He therefore decided that an Air Source Heat Pump was the way forward.
The heating system for the property includes both underfloor heating and a heat recovery system, ensuring an efficient and reliable installation. The underfloor heating system is part of a heavily insulated slab incorporating some 300mm of insulation, increasing the efficiency of the system. The pipework is split into six sectors, each connected to a thermostat, controlling the heating output.
A Ecotec 15kW Air Source Heat Pump was chosen following discussions with several manufacturers for the following reasons. The Ecotec device is the quietest heat pump on the market at 47dB @ 1m. The unit is neat and compact and easy to install. Support from the Ecotec team also ensured that the installation was smooth.
The heat pump has been set up to feed a 300 litre hot water cylinder at 60°C to ensure that there is no chance of Legionella bacteria getting into the system. (See Legionnaires Disease - Domestic Hot Water Systems datasheet on the Useful Information page). This tank is heated overnight to reduce costs as well as feeding water to the underfloor heating system at 45°C, providing a constant room temperature of 21°C.
So were there any problems with the installation? According to Fred it went very smoothly. The heat pump was turned on in December 2009, just as the worst winter for 30 years started to bite. Initially the room temperature was struggling to get to its target of 21°C, however this was put down to the building structure being so cold. As the thermal mass of the structure has warmed the internal temperature has become more than acceptable and will only improve as the final insulation is installed into the building.
As far cost savings, Fred used to own an identical house next door to the house he is currently building and reckons that he has seen an estimated 30% saving on electricity costs over the winter quarter. Again this will improve even more as the building is completed and the structures thermal mass stabilises.
Overall Fred is very impressed with the Air Source Heat Pump from Ecotec and would not hesitate in recommending them to anyone thinking of using one to heat their property.