Alternative Energy Forums

I've been researching the process of geothermal heating, but have a few questions I haven't been able to find good answers to. The fluid coming out of the ground will be about 50 degrees, how do you raise that to comfortable temperatures for home heating? Does it need a compressor? I thought it only used a heat pump. What exactly does the heat pump do? Does it only pump the fluid or does it also compress it? Any help here would be greatly appreciated.

bocata

Bocata

I heat pump moves energy from one place to another. This is why a heat pump works in Arizona in the summer. The outside is definitely hotter than what you want in the inside.

The temperature 6 feet down in most soils is around 50 to 55 degrees anywheres in the world. Even in the desert. The energy in the soil at 50 degrees is greater than the outside in a northern winter that is at zero degrees. The heat pump extracts the heat energy from the soil and the accumulative results will add energy to the inside of a home.

The heat pump is a compressor that will compress a gas to a liquid at one part of the cycle and than it is allowed to expand at the other side of the cycle and become a gas. There is a switch that changes where this happens depending on whether you are cooling or heating. It requires heat to cause the liquid to become a gas and it requires cooling to aide in the gas becoming a liquid. There are heat exchangers at each end of the cycle.

The heat exchanger outside is nothing more than a hundred or so feet of tubing buried in your back yard six feet down. The heat exchanger inside is a radiator that air passes through and has piping in the radiator where either the liquid becomes a gas or the gas becomes a liquid. Valving in the line will determine which processes is working. Sizing the system will determine the length required of the tubing.

Water or glycol(radiator liquid) is usually pumped through the tubing in the ground to a holding tank that contains the radiator with the air conditioning gas that is connected to piping in the house.

In winter the liquid becomes a gas outside gains energy and transports this energy to the house where cooler air must be extracted from the house to make the gas into a liquid. The gas is compressed and the air passing over the radiator cools the gas and it becomes a liquid. To become a liquid we must extract heat energy from the gas and this heat is added to our house. Keep in mind this is not temperature but an accumulative amount of heat that increases temperature.

The compressors will work harder when there is not enough heat or cooling available and compress the gas to a higher pressure so the gas will liquify. This will produce even more heat.

Hope this helps.

EcoOptions