I was wondering if someone could give me some ideas on a science fair experhyment I could do in geothermal heating and cooling. Thank you. Basically … Some ideas not prove accurate heating and cooling a small scale. Make students aware of closed loop systems, water or antifreeze solution is circulated through plastic pipes buried beneath the surface of the earth. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses to cool the building by pulling heat, taking it through the system and place it on the floor building. Why use a geothermal heating and cooling? To help prevent environmental pollution from fossil fuels such as heating oil, coal and wood. 5 gallon aquarium 1 inch ID pump aquarium sand polyvinyl tube Reptile Heating Mat You will need to form a "V" on both sides using the disposable aluminum cookie loose on the outside of the tank leaves stone. The "V" is the formation of the outer Earth. Step 1a. Reptile Heating Mat Set inside the tank bottom. Step 1b. Place the tubes directly on the vinyl mat close to another to be visible. Step 1c. Put 2 "of dark sand (8 cups) in 5 gallon tank. Step 2. Place 1 five-pound bag of aquarium gravel in this layer of sand (mix the two together.) Step 3. Put 2" of white sand (8 cups) in the top of the previous layer. Step 4. Place 2 "dark sand on top of the sand layer to play. Step 5. Put 1 bag of five pounds aquarium gravel in this layer. Step 6. Now have a total of five alternating layers of sand from light to dark .