Heat Pumps

A Heat Pump uses the same technology as your domestic fridge, in fact, a fridge is a type of heat pump. If you look behind your fridge you will notice the back of the fridge feels warm, this heat is a by-product of the refrigeration process. A heat pump used for generating thermal energy to heat a building basically uses this heat rather than wasting it like a fridge. In terms of a domestic fridge, the fridge compartment would be the energy source, equivalent to the air or ground, and the heat at the back of the fridge would be your heating system. A heat pump takes a low-grade temperature source and compresses it, which achieves the temperature required for heating our properties.

An ASHP relies on the ambient air temperature to provide the energy we need for our properties. The ambient air temperature is an ever changing source of natural energy as the air temperature changes throughout the year being at its coldest when the heat pump is most required in the winter. The air temperature has an impact on the electrical consumption of a heat pump as it uses less energy in milder weather due to the fact that the air temperature is nearer to the heat output temperature generated for heating compared to mid-winter.

ASHP’s can work in air temperatures as low as -20 degrees ASHP’s do not require the cost and disruption of excavating land or bore hole drilling works associated with ground source heat pumps; therefore they are often the favoured unit, especially when considering retro fit installations offering the most economical installation.

Horizontal ground loops

Horizontal ground loops require a large area of excavation to a depth of approximately 1.5m below ground level for installing ground loops. The size of excavation will depend on the size of the property being heated and the size of the heat pump.

Bore Hole ground Loops

A bore hole installation will require drilling a bore hole to a depth of between 50-150m into the ground and lowering two pipes connected with a U bend at the bottom all the way down to the bottom of the bore hole. These pipes are piped back to the heat pump. The depth and number of bore holes will depend on the size of the property and the size of the heat pump.

Ground Source Heat Pump

Ground source heat pumps (GSHP) A GSHP extracts its heat from the ground which has absorbed its energy from the sun. Unlike ambient air temperature the ground temperature remains reasonably consistent throughout the year, typically at 8-12 degrees depending on how deep you go into the ground. The deeper you go the less the seasonal ambient temperature will affect the ground temperature. Due to the consistent temperature of the ground, a GSHP’s electrical consumption remains reasonably consistent and easy to predict. Unlike an ASHP a GSHP is generally installed within the property with pipe lines extending from the unit to the ground, these are called ground loops and contain an anti-freeze water solution called brine.