STEP 1 : UNDERSTANDING HOW A GEOTHERMAL HEAT PUMP WORKS
This project goes over the build of a Geothermal heat pump that takes the hot air in your garage and cools it down by transferring that heat. The cold water is pulled out of the ground through a shallow hand-dug well and sent to a heat exchanger inside the garage. A fan attached to the heat exchanger blows out the cold air into the garage. The heat exchanger absorbs the existing heat inside the garage. The warmed-up water is then removed through an exhaust pipe.
STEP 2 : DIGGING A WELL USING A POST AUGER
Just a few feet down the earth is a consistent 55 degrees, summer or winter. Water at that depth is about the same temperature. To harness the cold water down below, we dig a shallow well. To do this we use a post auger and a 3-foot long well point that is attached to a 10-foot three-quarter inch pipe using a drive coupling. We start by digging a hole using the post auger till the water table is reached and then start driving using the good point for an additional two to three feet until it is submerged under the water table.
STEP 3 : DIGGING THE TRENCH AND CONNECTING THE WELL PIPE
A two to three-foot trench is dug from where the well is installed to the garage. A one-inch poly pipe is connected to the well pipe using a barbed coupling and is buried inside the two-foot trench all the way to a well jet pump. The trench is dug down at least two feet until you hit some hardpan clay which is about where the temperatures begin to be more constant. This keeps the pipe cool under the earth.
STEP 4 : CONNECTING THE JET PUMP
The other end of the poly pipe coming out from the trench is connected to a 1/2 HP Flotec Shallow well jet pump. The pump can be powered by a solar panel. The pump is kept outside the garage as it generates a lot of heat. If it is kept inside the garage, the cooling effect from the water will be undone by the heat generated by the pump.
STEP 5 : INSTALLING A WATER PRESSURE TANK
The output of the pump is connected to a three-quarter-inch copper pipe inside the garage. It is then further connected to a water pressure tank with the help of a brass tee and a union. A relief valve is also attached to the tee to empty the water tank if the pressure gets too high. A water pressure tank is used to prevent the pump from failure.It also acts as a buffer storage.
STEP 6 : CONNECTING THE HEAT EXCHANGER
The other end of the brass tee is connected to two pipes. One pipe goes outside the garage to a faucet and the other pipe is connected to a radiator that acts as a finned tube heat exchanger.
The heat exchanger captures the hot air surrounding the garage and stores the heat into the finned coils within the radiator. The heat is transferred to the water flowing through them. An exhaust line from the radiator carries this hot water outside the garage.
Two flexible hose pipes connect the input of the heat exchanger to the water tank and the output to an exhaust pipe. A box fan is placed in the front of the radiator to blow the cool air. The fan can be powered by Solar panels. Once the water starts running through the radiator, we start the fan
Image Credits : Historic House DIY