What is Geo-Exchange?

Geo-exchange systems (also commonly known as geothermal or ground-source heat pump systems) use heat pumps (based on vapour compression refrigeration technology) to move heat from one location to another. The relatively stable temperature of the earth can provide an efficient source (heating mode) or sink (cooling mode) for these systems. Heat exchange with the earth can occur with a closed loop of piping installed horizontally or vertically in the ground, or if there is adequate groundwater available an open loop system may be used.

Although geo-exchange systems use electricity to drive the heat pumps, well-designed and carefully constructed systems typically operate at a coefficient of performance (COP) between 3 and 4, meaning the heat pumps deliver 3 to 4 times as much energy as the compressor draws (with a result that 67% to 75% of the delivered energy is renewable energy transferred from the earth).

Geo-exchange systems can also be used to recover waste heat from one location or process and move it to another location where the heat may be used productively. In many cases, the ground can also be used to store waste heat between the time it is produced and the time it is needed.

Why Geo-Exchange?

Geo-exchange systems can have benefits, such as:

• By using renewable heat from the earth or capturing waste heat from other operations, geo-exchange systems can often reduce annual heating and cooling costs significantly.
• Geo-exchange systems operating on low carbon sources of electricity - like we have available in BC - can significantly reduce greenhouse gas emissions from burning fossil fuels for heat.