Ground-coupled Heat Exchanger - Water To Earth

Water To Earth

An alternative to the earth-to-air heat exchanger is the "water" to earth heat exchanger. This is typically similar to a geothermal heat pump tubing embedded horizontally in the soil (or could be a vertical sonde) to a similar depth of the earth-air heat exchanger. It uses approximately double the length of pipe of 35 mm diameter, e.g., around 80 m compared to an EAHX of 40 m. A heat exchanger coil is placed before the air inlet of the heat recovery ventilator. Typically a brine liquid (heavily salted water) is used as the heat exchanger fluid.

Many European installations are now using this setup due to the ease of installation. No fall or drainage point is required and it is safe because of the reduced risk from mold.