Drilling a 4" or 6" diameter hole into a garage floor and installing a PVC pipe to a depth of 10 feet will not effectively warm the garage without proper air circulation. It is recommended to create two holes joined at the bottom to facilitate air movement. Heat pumps are a more efficient alternative for heating, particularly if they can draw energy from a large underground reservoir. However, the effectiveness of heat pumps depends on the insulation of the garage and the local energy grid's emissions profile.
PREREQUISITESHomeowners considering heating solutions for garages, HVAC professionals, and anyone interested in energy-efficient heating technologies.
10 inches or 10 feet?KeithS said:and install a PVC pipe to a depth of 10"
Thank you for the catch! 10 Feetberkeman said:10 inches or 10 feet?
Thank you, I was hoping to just take the bite out of the air, but it sounds a little more involved than my wishful thinking! :)Andrew Mason said:Not unless you have air circulating down into the hole. Better to drill two holes joined at the bottom and circulate air down one and up the other. But unless you have the right kind of soil such that heat flow will occur continually from surrounding warmer parts to the parts around the hole, all you will be doing is allowing the ground 7-10 feet down around the hole to freeze.
Heat pumps would be a better option, but these will not be effective unless you can draw energy from a large underground reservoir. This can be done by an array of pipes running through the ground. They are expensive and don't really save ghgs unless you are using renewable source electricity.
AM
Modern heat pumps actually save GHGs even if powered by a pure natural gas generator. On a typical US grid mix, they are substantially lower emission than even a 97% ultra high efficiency gas furnace. If your local grid is almost entirely coal, you're probably better off with the furnace, but otherwise the heat pump is the way to go (even air source heat pumps, though ground source as you describe are more efficient). The heat pump also has the benefit that its emissions drop as the grid gets cleaner, so assuming you think the grid will continue trending in that direction, the lifecycle emissions will be even better than the current comparison would indicate (while a gas furnace will, of course, always be burning gas).Andrew Mason said:Not unless you have air circulating down into the hole. Better to drill two holes joined at the bottom and circulate air down one and up the other. But unless you have the right kind of soil such that heat flow will occur continually from surrounding warmer parts to the parts around the hole, all you will be doing is allowing the ground 7-10 feet down around the hole to freeze.
Heat pumps would be a better option, but these will not be effective unless you can draw energy from a large underground reservoir. This can be done by an array of pipes running through the ground. They are expensive and don't really save ghgs unless you are using renewable source electricity.
AM
Unless your garage is well insulated you won't likely to notice the difference.KeithS said:would the geothermal heat keep my garage warmer?
If the waste heat from the 25% efficient natural gas generator was used to heat the garage and the electricity generated was used to run a properly installed heat pump, then you will be saving energy and ghgs over a gas heater, regardless of temperature difference. I'm not sure about cost effectiveness, though.cjl said:Modern heat pumps actually save GHGs even if powered by a pure natural gas generator.