Beginning in the 1970s, geothermal heat pumps came into common use. Geothermal heat pumps provide central air conditioning as well as heating as a matter of course. And they are installation-cost competitive with a central combustion furnace/central air conditioner combination.
Geothermal heat pumps operate by moving or transferring heat, rather than creating it. During the winter months, the geothermal heat pump refrigerant captures heat from outdoor air, compresses it and releases this warm air inside the home or business. During the summer, the process is reversed; the geothermal heat pump refrigerant captures heat from inside the home or business and transfers it to the pipes buried in the Earth.
Much less electricity is used to move heat rather than create it, making geothermal heat pumps more economical than resistance heating. Because they are working from those constant earth temperatures, the system provides more even temperatures throughout your home resulting in ultimate comfort to you and your family.
Depending on climate, geothermal heat pumps (including their supplementary resistance heat) are about 1.5 to 3 times more efficient than resistance heating alone. Operating efficiency has improved since the 70s, making their operating cost generally competitive with combustion-based systems, depending on local fuel prices. Another advantage to this system – there is no outdoor unit – thus no concern about outdoor noise.
Ground source heat pump technology is the wave of the future, but the concept isn’t new at all. In fact, Lord Kelvin developed the concept of the heat pump in 1852. In the late 1940’s, Robert C. Webber, a cellar inventor, was experimenting with his deep freezer. He dropped the temperature in the freezer and touched the outlet pipe and almost burned his hand. He realized heat was being thrown away, so he ran outlets from his freezer to his boilers and provided his family with more hot water than they could use! There was still wasted heat, so he piped hot water through a coil and used a small fan to distribute heat through the house to save coal. Mr. Webber was so pleased with the results that he decided to build a full size heat pump to generate heat for the entire home. Mr. Webber also came up with the idea to pump heat from underground, where the temperature doesn’t vary much throughout the year. Copper tubing was placed in the ground and Freon gas ran through the tubing to gather the ground heat. The gas was condensed in the cellar, gave off its heat and forced the expanded gas to go through the ground coil to pick up another load. Air was moved by a fan and distributed into the home. The next year, Mr. Webber sold his old coal furnace.
In the forties, the heat pump was known for its superior efficiency. The efficiency was especially useful in the seventies. The Arab oil embargo awakened conservation awareness and geothermal launched interest in energy conservation despite cheap energy prices. That is when Dr. James Bose, professor at Oklahoma State University, came across the heat pump concept in an old engineering text. Dr. Bose used the ideas to help a homeowner whose heat pump was dumping scalding water into his pool. Dr. Bose fashioned the heat pump to circulate the water through the pipes instead of dumping the water into the pool. This was the beginning of the new era in geothermal systems. Dr. Bose returned to Oklahoma State University and began to develop his idea. Since then, Oklahoma has become the center of ground source heat pump research and development. The International Ground Source Heat Pump Association was formed in Oklahoma, and is based on the campus of Oklahoma State University, where Dr. Bose severs as executive director.
-Courtesy of the GeoExchange.com
Central heating systems have been considered a necessity in our homes and businesses for many years. When comparing available systems, consumers should carefully consider safety, installation cost, operating costs, maintenance costs, and comfort.
Types of Systems
There are two basic types of systems — those that require a flame to operate (i.e., combustion based), and those that do not. Most central systems presently installed create heat by combustion, just as they did in the early part of the century. These systems use a furnace to burn a fossil fuel (such as oil, natural gas or propane) or, in some instances, wood. More advanced, non-combustion systems operate by transferring or moving heat from one location to another.