Heat Exchangers/Geothermal

Heat Exchangers.

Heat exchangers provide mechanical ventilation for the home. Also referred to as (H.R.V.) Heat Recovery Ventilation the principle is to continuously change the air in the house and use the recovered heat to warm the incoming air. Points for extracting air are from wet locations such as bathrooms, kitchen, utility and W.C's. The heat from the extracting air is effectively transferred by the heat exchanger to the incoming air. The incoming air is then supplied to other areas of the house such as living rooms, bedrooms and study. The advantages being that the heat kept within the home reduces the need for continuous space heating.

Electrically operated, the unit is usually placed in the loft/attic therefore any noise should be hidden.

To operate most efficiently in our opinion a heat exchanger should only be used in a sealed home. Efficiency will vary from unit to unit but should operate at 90% plus levels.

Heat Pumps.

Heat pumps effectively extract heat from one source and transfers it to heat the home via radiators or more effectively by underfloor heating. There are two types of heat pump:-

1. Geothermal

2. Air to water

Geothermal Pump.

Geothermal pumps extract the heat from the ground. This is done by either

a) laying pipes around the garden beneath the surface or

b)) boring a hole into the ground

A number of factors need to be taken into account including soil conditions, size of garden area when laying the pipes and future proposals regarding possible extensions and landscaping.

In confined spaces a bore hole is a better method although it is the more expensive route.

Air to Water Heat Pump

An air to water heat pump system extracts the ambient heat from the air transferring it through the heat pump to the heating system.

All heat pumps are ideally suited for underfloor heating as such systems operate at a lower temperature than radiator heating. All heat pumps are available with good management systems for separate zoning and controls. All heat pumps use electricity to raise the temperature of the liquid within the heating system above that gained from its source to the required temperature. During extremely cold spells, particularly in the case of air to water heat pump the efficiency of the system will reduce. If this can be supplemented with photovoltaic panels cost effectiveness is improved.

Although not necessary, in order to reduce the energy needs to heat water in such circumstances we would recommend combining heat pump system with a solar thermal panel for the hot water. This would however depend upon the property, life stye and hot water useage of the occupiers.