Geothermal

GEOTHERMAL HEATING AND COOLING

Geothermal heat pumps, also known as the ground source heat pumps, are high efficient heating and/ or air conditioning unit, which is becoming more popular with both residential and commercial buildings. Geothermal heat pumps have the ability to heat, cool, and even heat your water without using any fossil fuels, all for a fraction of the cost.

The geothermal system operates based on the fact that underneath the earth’s surface is a constant temperature of 55° F though out the year. During the heating season a special fluid circulates through the pipe where heat energy is transferred from the ground to the fluid and then to the heat pump unit located in the home or building, providing a source of heat. Inside the building, the heat can be distributed through out by either a forced air duct system or hot water radiant heat.

To provide air conditioning, the process is reversed. Heat is removed from the home and transferred to the loop fluid. As the warm fluid travels through, the pipe in the earth serves as a “heat sink”—a place to deposit the heat removed from the home.

HOW THE HEAT PUMP WORKS

Geothermal heat pumps basically works the same way as your air source heat pump do. An air source heat pump will extract heat from outdoor air and pump into your house or building. The only difference with geothermal is that instead of extracting heat from the air it extracts heat from the earth where the temperature is constant and doesn’t vary like air temperatures.

After the fluid has passed through the ground and into the house that’s when the heating process begins. The fluid comes into the house at a low heat temperature. A substance called a refrigerant carries the heat from one area to another.

The compressor in your outdoor unit will change the gaseous refrigerant into a high temperature, high-pressure gas. As that gas flows through the outdoor coil, it loses heat. That makes the refrigerant condense into a high temperature, high pressure liquid that flows through copper tubing into the evaporator coil located in your fan coil unit or attached to your furnace.

At that point, the liquid refrigerant is allowed to expand, turning the liquid refrigerant into a low temperature, low pressure gas. The gas then absorbs heat from the air circulating in your home's ductwork, leaving it full of cooler air to be distributed throughout the house. Meanwhile, the low temperature, low-pressure refrigerant gas returns to the compressor to begin the cycle all over again.

While your heat pump cools the air, it also dehumidifies it. That's because warm air passing over the indoor evaporator coil cannot hold as much moisture as it carried at a higher temperature, before it was cooled. The extra moisture condenses on the outside of the coils and is carried away through a drain. The process is similar to what happens on a hot, humid day, when condensed moisture beads up on the outside of a glass of cold lemonade.

The same process works in reverse in a heat pump during the winter. The heat pump takes heat out of the ground and it moves that heat inside, where it is transferred from the evaporator coil to the air circulating through your home.

That's not a typographical error, by the way- the heat pump moves heat from outside to warm your home, even on a cold day. That's because "cold" is a relative term. Air as cold as 30 degrees still contains a great deal of heat - the temperature at which air no longer carries any heat is well below -200 degrees Fahrenheit. A heat pump's heat exchanger can squeeze heat out of cold temperatures, then transfer that heat into your home with the help of a fan, which circulates the warm air through your ducts.

Heat pumps are often installed with back-up electric resistance heat or a furnace to handle heating requirements when more heat is needed than the heat pump can efficiently extract from the ground.

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We understand that this might be a hard concept to grasp, but we can help. Give us a call at (973) 762-4141 or email us at info@rghdevelopment.com.