STEP 1: Understanding the Functionality of a Geothermal Heat Pump
This project outlines the development of an innovative geothermal heat exchanger aimed at efficiently cooling a garage environment. The core concept involves extracting cool water from a shallow well and channeling it through an internal heat exchanger installed within the garage. A fan mounted on the heat exchanger then disperses cooled air into the space, while the system simultaneously absorbs heat from the garage interior. The heated water is expelled via an exhaust pipe, completing the cycle. This setup leverages the stable underground temperature a few feet below the surface, which remains relatively constant year-round. Installation begins with digging a shallow well using a post auger, followed by connecting a water pump and pressure tank to the well pipe. A one-inch polyethylene pipe is laid within a trench to connect the well to the garage, facilitating the transport of chilled water efficiently.
STEP 2: Excavating a Well Using a Post Auger
The shallow well serves as a vital component of the geothermal cooling system, granting access to the Earth’s naturally cool subsurface temperature, which is unaffected by seasonal fluctuations. To tap into this resource, a post auger is employed to drill until reaching the water table. A three-foot long well point is affixed to a ten-foot, three-quarter inch pipe through a drive coupling, enabling water extraction. The auger is driven into the ground until it contacts the water table, at which point the well point is attached and driven an additional two to three feet deeper, ensuring it is submerged below the water level. This setup guarantees a steady supply of cool water for the system, harnessed directly from the earth’s natural thermal reservoir.
STEP 3: Excavating the Trench and Connecting the Well Pipe
To facilitate the movement of chilled water from the well to the garage, a trench approximately two to three feet deep is excavated, with the length determined by the property layout. Once the trench is prepared, a one-inch polyethylene pipe is connected to the well pipe with a barbed coupling, creating a sealed pathway for the cold water. This pipe is then buried within the trench, which helps maintain a low temperature for the water as it travels underground. To optimize thermal stability, it is recommended to dig the trench to a depth of at least two feet, reaching the hardpan clay layer, where the temperature remains more constant, thereby ensuring the pipe remains cool and the water temperature consistent.
STEP 4: Installing the Jet Pump for Water Circulation
The other end of the polyethylene pipe extends to a 1/2 HP Flotec shallow well jet pump, which is essential for circulating water through the system. Notably, this pump is designed to operate efficiently with a solar power source, reducing energy consumption and promoting sustainability. For optimal performance, the pump should be installed outside the garage in a shaded area, as it generates significant heat during operation. Placing it outdoors prevents unnecessary warming of the water, maintaining the system’s cooling efficiency. Proper installation ensures reliable water flow from the well to the heat exchanger, forming the backbone of the geothermal cooling process.
STEP 5: Installing a Water Pressure Tank for System Stability
The output from the jet pump is connected to a three-quarter-inch copper pipe running inside the garage. To regulate water flow and protect the pump from potential failure, a water pressure tank is integrated into the system, connected via a brass tee and union. A relief valve is also installed at this junction to safely release excess pressure and prevent damage. The pressure tank acts as a buffer, storing water and smoothing out fluctuations in flow, which extends the lifespan of the pump and enhances overall efficiency. This setup ensures a steady, reliable supply of chilled water, vital for effective cooling performance inside the garage.
STEP 6: Connecting the Heat Exchanger and Distributing Cool Air
The brass tee’s opposite outlet directs water to two separate pathways. One leads to an external faucet, providing a versatile source of cold water for other uses, while the other directs water into a radiator that functions as a finned tube heat exchanger. The radiator captures and transfers heat from the surrounding hot air into the flowing cold water. This process involves finned coils that store the heat absorbed from the garage environment. Two flexible hoses connect the heat exchanger’s inlet and outlet to the water pressure tank and an exhaust pipe, ensuring a continuous flow of water through the system. A high-efficiency box fan is positioned in front of the radiator to blow cooled air into the garage, creating a comfortable environment. Powered by solar panels, the fan operates sustainably, circulating the cooled air effectively. Once water begins circulating through the radiator, the fan is activated, producing a steady flow of cool air that maintains a pleasant indoor temperature while minimizing energy consumption and environmental impact.
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