In Perspective - Ground Source Heat Pumps
Harry Applin
We have been talking about energy efficiency over the last few months. The one obvious thing about energy efficiency approach is that the initial cost is higher than conventional approach. The simple light bulb is a good example. They are inexpensive but highly inefficient. The same goes with heating/cooling system for the home. Oil, coal or natural gas have an efficiency rating of about 80% or less. Natural gas can be more efficient but increasing the furnace from 80% to 90% will almost double the cost, but will still be around $2,000 not including installation. The ground source efficiency is rated at 300%-400%, this means that the system will deliver three to four units of energy to the home for every unit they consume.
Most people are immediately turned off by the initial cost of this system, which is around $24,000 installed without rebates or tax incentives. But what most people don't look at is that the system is also an air-conditioning system and can be used to assist the water heater. But when you add in the payback time the outlook for ground source systems can be quick. If you use electricity or oil for your heat, the payback can be less than five years at current prices, while an efficient natural gas system would take closer to 10 years. When you include residential insulation improvements the payback and savings can be even higher.
One should also look into including the cost in a mortgage, your ground source system will have a positive cash flow from the start. Adding the system to the mortgage may increase your payments by $50. The energy cost savings will easily exceed that added mortgage amount over the course of each year and as we all know, energy costs are rising yearly.
One of the other advantages to ground source is that they use a similar amount of electricity as a hi-end refrigerator. This makes the system more adaptable to solar electrical systems and when you consider the cooling ability it is even more attractive.
Ground source heating is also a great selection for radiant heating systems. A couple of advantages to radiant heating are: it is more efficient than baseboard heating and usually more efficient than forced-air heating, the lack of moving air can also be advantageous to people with severe allergies and radiant (liquid-based) systems use little electricity and as previously stated is a great benefit for homes off the power grid.
Ground source heat pumps are also durable and require little maintenance. The underground piping used in the system is often guaranteed to last 25 to 50 years and is virtually worry-free. The components inside the house are small and easily accessible for maintenance and have warranties in the range of 10 to 15 years. Other advantages are that there is no chimney, which is also a source of heat loss in a home. There are very little emissions from ground source units. The emissions would only be apparent if the electrical source is using fossil fuels. Ground source systems are also proven technologies having been used in buildings since the 1940's. Many of these early systems are still in use and have saved their owners many thousands of dollars over the years.
To find out more about financing and incentives that are available to you, visit the Database of State Incentives for Renewable Energy (DSIRE) Web site at
Information on Ground Source Heating can be found at
http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm?mytopic=12640
http://www.consumerenergycenter.org/home/heating_cooling/geothermal.html