Geothermal to Heat a Greenhouse

Q: I have a dry water well borehole that I’d like to use for geothermal / geoexchange to heat my greenhouse.

A: Your borehole can heat and cool a greenhouse of 1,000 to 2,000 sq ft depending on what temperatures you want to maintain. With the geothermal / geoexchange system you can keep the greenhouse mostly “closed”, meaning when it’s sunny, instead of opening the vents and dumping the precious heat, you will cool the plant zone instead and move the heat into the borehole. That night when you want to heat, the warmed borehole will return the day’s heat into the greenhouse. This is where you save lots of money because you’re using the day’s earlier solar gain instead of buying the heat energy from your favourite utility.
This system can be taken a giant step forward yet by changing the typical outdated heating methods to heating the plant zone instead of the whole space. You’ll need an air handler (a box with a fan and some coils in it) and some plastic ducting that will blow the conditioned air into the plant zone instead of the ceiling space. This will give you much improved plant yields and further energy savings. In essence you are abandoning the upper area of the greenhouse that is normally heated (uselessly) and you’re only heating/cooling/(de)humidifying the place that matters: the plant zone.

We can design and build the geothermal / geoexchange system for greenhouse heating in-house and we have partners who specialize in this new air handling technology.

Hoping this sheds some “warmth” on the subject!