How Heat Pumps Work

Basic Functioning

A heat pump is essentially a refrigerator working in reverse. The refrigerator extracts heat from within the unit and dumps the heat to the outside. The heat pump on the other hand works with the pseudo purpose of cooling the outside environment and transferring the heat inside the building.

A heat pump is a highly efficient use of energy for heating. It is far more efficient than using gas, oil or electricity.

An additional advantage is that during the summer, the heat pump operation mode can be reversed to provide cooling for the property.

Types of Heat Pumps

There are two basic types of heat pumps:

• one extracting heat from the outside air
• one extracting heat from the ground normally from coils buried underground

The Air-to-Air Heat Pump

This type of heat pump works by extracting heat from the outside air and circulating that heat within the building. This type of heat pump is relatively easy to install. It functions well with the minimum winter temperatures of southern coastal British Columbia.

The Geothermal Heat Pump

This type of heat pump works by extracting heat from under the ground (sometimes under water) using buried loops. For the ground loops, one can use either vertical loops or horizontal loops.

Horizontal Coils

The vertical loops are prepared by drilling a series of holes into the earth to a depth of 30 or more metres. The number of holes and depth depends on the size of the building being serviced and the lowest wintertime temperatures. The horizontal loops are prepared by removing the upper layers of soil on the property, laying the loops and then returning the soil. The depth must be below the frost line (on the Prairies, typically 2 to 2.5 metres down).

The advantage of this type of operation is that the earth's temperatures below the frost line remain reasonably constant throughout the year and the efficiency of the heat pump likewise remains reasonably constant.

The disadvantage is of course the higher installation costs.

Which Type of Heat Pump ?

In deciding which type of heat pump to choose, you must first consider your location and the lowest wintertime temperatures. Then if the air-to-air heat pump is still an option, you must weigh the additional installation costs of the geothermal heat pump against the higher operating costs of the air-to-air heat pump.

Please contact us to discuss the pros and cons for your location.