How They Work

As the prices of oil and natural gas continue to rise homeowners continually find it’s more and more expensive to heat their homes. And with rising energy costs it’s certainly not cheap to air-condition a house in the summer either.

To heat or air condition

Geothermal pumps offer an alternative to conventional heating and air-conditioning systems that is safe, renewable, environmentally friendly and inexpensive to operate.

Geothermal pumps harness the earth’s natural heat contained in the ground and water around your home. This heat is extracted using a ground loop installed underneath the ground around your house. The air warmed or cooled to whatever temperature you desire, providing year around comfort without the use of fossil fuels and without damaging the environment. Best of all, geothermal pumps can be installed in new construction or existing homes.

At Geothermal Specialist Inc., we specialize in providing a variety of geothermal pumps throughout Northern Indiana, Southwestern Michigan and even reaching over into Northeastern Illinois.

Studies by the Environmental Protection Agency have shown that homes utilizing geothermal pumps reducing heating costs by up to 70%, quickly saving more than the initial costs of pumps themselves

To heat potable domestic hot water

The ability for geothermal systems to heat domestic water is an option from the factory. If heating water is desired, the unit must be ordered with this option. Typically most systems use the hot refrigerant exiting the compressor to heat water in an additional heat exchanger. This type of water heating option is known as a “de-superheater” or as a “HWG (Hot water generator)”. The sequence of operation requires a call for heat (or cooling) from the thermostat AND a call for heating water. The sales pitch is free hot water when air-conditioning… however, most geothermal systems used in Michigan, Indiana, Illinois, Ohio and Wisconsin are used less than 20% of the time for cooling.

When there is a call for hot water in the winter, half of the heat is diverted from heating the house for the first 5 to 20 minutes in order to bring the water up to temperature in the hot water storage tank. The temperature of the air exiting the registers will be cooler until the water temperature is satisfied because there is only half as much heat available. Once the hot water temperature is satisfied then all the geothermal system’s capacity is dedicated to heating the home.

In the milder spring and fall there may be some occasions when the thermostat isn’t calling for heating or cooling and there is a need to bring the water up to temperature. Most contractors set the temperature settings of the conventional hot water heater a couple degrees less than the typical geothermal settings to pick up the slack in the off seasons.

A couple manufacturers hold patents which dedicate all the BTU capacity of the system to heating water. This option also must be ordered from the manufacturer. Typically they have twice the BTU potential of other manufacturers, which means twice the recovery similar to the recovery performance of a gas or propane water heater. A “dedicated” water heating option has an installed price usually over $2000 which is more than twice the investment of “desuperheater / hot water generator” systems.

The options require an insulated storage tank (a typical water heater). Water is circulated from the storage tank through the geothermal system and back to the storage tank. Due to the performance of common refrigerants, water storage temperatures usually peak out around 124 – 128 degrees Fahrenheit.

To heat or chill hydronic water

Many builders, heating contractors, and even some homeowners traditionally think of hydronic heating in terms of a fuel fired boiler. Some radiant systems require temperatures in excess of 160 degrees Fahrenheit. With current technology, geothermal systems are capable of producing water temperatures up to 125 degrees. Radiant floor systems need temperatures 110 degrees and lower, and are therefore well served by Geothermal hydronic heating systems. And Geothermal radiant heat will save a homeowner between 40% and 85% on the heating bills when compared to fossil fuel fired boilers.

The same percentage of savings applies to heating domestic potable water. Homeowners are delighted to have the most environmentally friendly, lowest operational cost, and long-term reliability of geothermal systems providing their hydronic heating needs.

To provide source of heat transfer by loop or well water

A refrigerator uses refrigerant to transfer heat from one airspace to another. This process is air to air heat transfer. A Geothermal system uses the refrigerant to transfer heat in a process referred to as water-to-air or water-to-water. The refrigerant picks up heat from earth temperature fluid and carries it to an air handler for forced air heating or to a fluid heat exchanger for radiant heating.

The ideal fluid source is ground water – typically between 50 and 52 degrees as it enters the heat exchanger, where refrigerant gains BTUs (in the heating mode) or loses BTUs (in the air conditioning mode).