Geothermal Heating & Cooling

The main reason for the high installation cost of ground-source heat pumps is the long run of tubing required to transfer heat to and from the ground.

Growing interest in energy efficiency and renewable energy has put geothermal heat pumps in the spotlight. Also known as "ground-source" heat pumps, this type of system provides a home with heat, air conditioning (cooling) and —in some cases—even hot water. And a ground-source heat pump can accomplish these tasks more efficiently and thus less expensively than most other HVAC options.

How Geothermal Systems Work

A ground-source heat pump works just like an air-source heat pump using electricity to pump a refrigerant through compression and expansion cycles, thus "pump" heat from one location to another.

The main difference is that a ground-source heat pump relies on the consistent temperature of the earth (6ft. or more below the surface) rather than the ambient air temperature as its heat source and heat sink. At this depth, the earth's temperature will be between 45 and 75 degrees, whether it's summer or winter, whether you're in Florida or Minnesota. An air-source heat pump becomes inefficient at supplying heat when outside temperatures drop below freezing. This never happens with a ground-source heat pump, which can work at very high efficiency all year long.

Dr. Energy Saver Watertown, NY can test and evaluate your existing HVAC system, along with numerous other features that affect home energy performance. By providing you with a prioritized selection of energy upgrades and completing the improvements you select, we'll make sure that your investment in energy savings suits your needs.

Weighing the pros and cons of geothermal heat pumps.

Energy efficiency is the primary advantage of a geothermal heat pump. The Environmental Protection Agency estimates that a geothermal heat pump can reduce energy consumption up to 44% compared to air-source heat pumps and up to 72% compared to an HVAC system that combines electric resistance heat with standard central air-conditioning.

If you invest in a geothermal heat pump system, you can expect reliable long-term performance. There are very few moving parts in this type of HVAC system, and they're all located inside the house where they're protected and easily accessible.

The two main "cons" with geothermal heat pumps are cost and installation requirements. Long runs of plastic tubing are required to transfer heat to and from the earth in a geothermal system. In a horizontal installation, the tubing is buried in trenches, as shown in the drawing. Alternatively, it can extend vertically into deep holes bored in the ground. It can also extend along the bottom of a pond or lake.

All of these options are expensive, and a horizontal installation requires a certain amount of land. The type of tubing installation is best determined by an experienced geothermal heat pump contractor after a site visit.

Bottom line: An excellent option, but not always the best option.

There's no doubt that a geothermal heating system offers performance that few other HVAC systems can match in terms of efficiency. However, its high cost and special installation requirements mean that it's not the best choice for many homeowners.

Related Pages:

• Radiant Heating
• Forced Air Heating
• Solar Heating