Geothermal Heating and Cooling

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Geothermal Heating/Cooling Systems
Residential Environmental Design, unknown published date, unknown author

The application of geothermal heating/cooling, also known as ground source heat pumps, has been named "the most energy-efficient and environmentally sensitive of all space conditioning systems", by the Environmental Protection Agency. The system's basic concept takes advantage of the earth's constant temperature, approximately 55 degrees, to heat and cool a building. By tapping this steady flow of heat from the earth in the winter, and displacing heat in the earth in the summer, a geothermal heat pump can save homeowners 40 to 70 percent in heating costs and 30 to 50 percent in cooling costs compared to conventional systems.. read more

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In the pursuit of sustainable environment, systems with high efficiency and produce less pollution are brought into perspective. Geothermal would provide a solution for energy efficiency and an option of renewable energy. Since 1960, geothermal has been applied in power generation at locations with geothermal resources such as steam, hot springs and hot dry rock.

During the late 90s, another application was introduced from geothermal and received lots of attention since. Heating, ventilation and air conditioning (HVAC) of buildings had benefited greatly from the development of geothermal technology. It is said that geothermal provides high efficiency and eco-friendly solution for heating and cooling purposes.

Geothermal systems work with the environment to provide clean, efficient, and energy-saving heating and cooling the year round. Geothermal systems use less energy than alternative heating and cooling systems, helping to conserve our natural resources. Geothermal systems do not need large cooling towers and their running costs are lower than conventional heating and air-conditioning systems.

A geothermal heat pump system is a heating and/or an air conditioning system that uses the Earth's ability to store heat in the ground and water thermal masses. Geothermal heat pumps are similar to ordinary heat pumps, but use the ground instead of outside air to provide heating, air conditioning and, in most cases, hot water. Because they use the earth's natural heat, they are among the most efficient and comfortable heating and cooling technologies currently available.

Studies had shown that by switching on to geothermal system, a significant amount of savings could be made in terms of monetary and pollution loads. Geothermal systems save homeowners 30-70 percent in heating costs, and 20-50 percent in cooling costs, compared to conventional systems. Geothermal systems also save money in other ways. They are highly reliable, require little maintenance, and are built to last for decades. They add considerably to the value of homes.

Geothermal systems also support the 'green building concept' which encompasses the practice of increasing efficiency with which buildings use resources — energy, water, and materials — while reducing building impacts on human health and the environment during the building's lifecycle, through better siting, design, construction, operation, maintenance, and removal.

In terms of environment-friendliness, the current use of geothermal heat pump technology has resulted in the following emissions reductions

• Elimination of more than 5.8 million metric tons of CO2 annually
• Elimination of more than 1.6 million metric tons of carbon equivalent annually

These 1,000,000 installations have also resulted in the following energy consumption reductions

• Annual savings of nearly 8,000 GWh
• Annual savings of nearly 40 trillion Btus of fossil fuels
• Reduced electricity demand by more than 2.6 GW

The impact of the current use of geothermal heat pumps is equivalent to

• Taking close to 1,295,000 cars off the road
• Planting more than 385 million trees
• Reducing U.S. reliance on imported fuels by 21.5 million barrels (3,420,000 m³) of crude oil per year.

In all types of geothermal systems, the heat from the ground is transferred in storage tanks in buildings, where it is used for domestic hot water or even forced-air heating system. In some cases the heat is boosted through reverse refrigeration technology (the compressor system in a fridge works by flowing the air through it; this uses the reverse in order to heat it). Geothermal systems can also deliver effective air conditioning during hot weather as well as heat during cold weather.

Illustration courtesy of Green Living for Dummies

Geothermal heating and cooling, or geothermal technology in general, is still an alien to Malaysian. This may due to the fact that Malaysia is not blessed with geothermal resources. However with the development of geothermal (ground source) heat pump, there are a lot of opportunity as cooling system in Malaysia currently depends totally on air-source heat pump.

The main barriers for geothermal heating and cooling in Malaysia are the economics and expertise. A geothermal system can cost as much as 30 percent more than conventional heating and cooling systems. Another drawback to geothermal installation is the lack of qualified contractors who know how to properly design, install, and service the systems.

Malaysians drilling engineers who are sick and tired of life off-shore may want to venture into geothermal installation field. The installation is very similar to drilling the earth for oil except for the part where looping pipes are inserted into the bored ground to allow water circulation for heat removal.

References

Jeffer. Y., Barclay, Liz., Grosvenor, M. (2008). Green Living for Dummies, Wiley Publishing Inc.

F. Rui., Jiang. Y., Yao, Y., Ma. Z. Theoretical study on the performance of an integrated ground-source heat pump system in a whole year Energy, 32(11), 2199-2209.

http://en.wikipedia.org/wiki/Geothermal_heating

http://en.wikipedia.org/wiki/Geothermal_heat_pump

http://geoexchange.org/