There is obviously a capital cost to install a heat pump system, but the energy source (from under ground, under water or the air) is free of charge and carbon.
Some electricity is required to pump the heat and to transform a large volume of low temperature heat into a smaller amount of heat at a higher temperature. From an economic perspective, the efficiency of a heat pump, known as the Coefficient of Performance (CoP) is key.
A CoP of 4 is a reasonable rule of thumb for a ground source heat pump to make financial sense. This means that, for every 1 unit of electricity required to operate the system at the desired temperature, the output will be 4 units of heat ...or cooling. The CoP reduces as the desired delivery temperature increases, so the economics of heat pumps favour low temperature distribution systems, eg underfloor or warm air heating.
Whilst the CoPs of water and air sourced pump systems are lower than ground sourced, the capital costs of the system are also lower. Ground source systems require trenches or boreholes for the pipes which are needed for the heat extraction. These pipes can just be laid in water, and no pipes at all are needed for air sourced systems.
Which system is most appropriate for a building depends on a number of factors that vary considerably from site to site and according to heating needs.
However, the most critical factor in all projects is accurate sizing of the system. This cannot be overstated to ensure the most efficient and cost effective installation.
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If you would like to know more about heat pumps (ground, water or air sourced) or would like to see how we could assist you, please email us at solutions@watt-knots.co.uk with your name and 'phone number and we'll be in touch.
