Help the Environment with a Hydronic Green Energy System
Ground source and geo-exchange systems exploit the differential between the earth’s mean temperature (typically down to about 225′ from the surface) and the outside air temperature. The earth stores the heat that it absorbs from the sun. Depending upon the region, ambient soil structure, presence of water, etc., the temperature of the earth at these depths hovers around 45 to 60 degrees Fahrenheit. During the heating season, heat is extracted from the earth and through a heat pump. That heat is distributed to the building using either radiant floors or forced-air. During the cooling season, the process is reversed; heat is extracted from the building and distributed back into the earth.
In our area, this is accomplished by drilling a series of 4 7/8″ holes to a depth of between 175′ and 225′. The number of holes required depends primarily on the size of the building. Piping containing water (and an antifreeze component) is looped down and up each hole, and then everything is filled with grout similar to that used in drilling for oil or natural gas. The system is closed, meaning that the liquid stays within the system; nothing is taken from or added to the earth except heat. The liquid within the system is pumped into the building, where the extraction or exchange process takes place. The tops of the holes are generally located about 6 feet below the surface, and all manifolds and piping to and from the building are underground. No maintenance is required for the loop fields, as the holes and piping are called, and have a useable life of at least 50 to 100 years.
Is ground source/geo-exchange technology new? Geo-exchange technology is not new. Albert Einstein used the technology to heat and cool his home in New Jersey in the 1920s. Between then and about 1980, it was not widely used, but has since been successfully used in both commercial and residential applications. In fact, the number of systems in the United States currently in place reaches into the hundreds of thousands. Considering rising energy prices, uncertainty about supply, and the need to preserve the integrity and beauty of our environment, geo-exchange technology is a compelling solution to all of our heating and cooling needs.
Interesting Facts about Geo-Exchange
- According to the Environmental Protection Agency, geo-exchange is the most energy-efficient, environmentally clean, and cost-effective space conditioning system available
- Energy costs with geo-exchange typically are 25 to 50 percent less than other HVAC systems
- The use of geo-exchange lowers electricity demand by nearly 1 kW per ton of capacity
- Today, more than 650,000 geothermal heat pump units are installed in the U.S., resulting in an annual savings of 5.2 billion kWh, 26 trillion BTUS of fossil fuels, reduced electricity demand by 1.7 million kW, and the elimination of nearly 4 million tons of CO2
- Those 650,000 installations are equivalent to the following:
- Taking 840,000 cars off the road
- Planting 250 million trees
- Reducing US reliance on imported fuels by 14 million barrels of crude oil per year
- Because they burn no fossil fuels on site, geo-exchange systems generate virtually no carbon dioxide emissions
- For businesses, geo-exchange systems provide the architect with optimal design flexibility because the roof and landscape are free of chillers, air handlers, and other outdoor equipment. In addition, with geo-exchange systems, boiler rooms can be eliminated and the size of mechanical rooms can be reduced
- Because geo-exchange systems are so flexible, they are ideal for renovating buildings with historical merit. One successful strategy is to use smaller heat pumps dispersed in closets, basements, and attics to provide space conditioning and ventilation with minimal ducting. Additionally, there are no unsightly condensers on the roof or grounds to distract from the building’s historic charm
- The elimination of outdoor or rooftop equipment means the geo-exchange system is not exposed to temperature extremes, dirt, pollution, or vandalism
- Geo-exchange systems have a lower lifecycle cost than conventional systems, even in hot, humid regions where the demand for air conditioning is high. Geo-exchange systems also have long equipment life (20+ years)
- If every school district that needed to replace heating and cooling systems over the next 10 years decided to install geo-exchange systems, the total energy savings over that time would exceed $11 billion
- If every school that could use geo-exchange did so, that would save the electricity required to power one million homes for a year
- EPA found that geo-exchange systems can reduce energy consumption—and corresponding emissions—by over 40% compared to air source heat pumps and by over 70% compared to electric resistance heating with standard air conditioning equipment. Combining geo-exchange with other energy-efficient measures, such as window or insulation upgrades, can increase these savings even further.
Geo-exchange systems use Earth’s energy storage capability to heat and cool buildings and to provide hot water. The earth is a huge energy storage device that absorbs 47% of the sun’s energy—more than 500 times more energy than mankind needs every year—in the form of clean, renewable energy. Geo-exchange systems take this heat during the heating season at an efficiency approaching or exceeding 400% and return it during the cooling season.
Solar Hot Water
The purpose of solar hot water systems (SHW) is to convert sunlight into heat that is then transferred by means of a fluid to solar collectors located on your roof to the water in your house. The end result saves you money by reducing the need for your water heater to run many times by 50 to 80%. Solar hot water systems operate very simply. With conventional water heaters, each time you use hot water, cold water replaces that used amount within the heater and the heating process begins. With a solar hot water system, each time you use hot water, heated water (sometimes at a higher temperature) from the solar storage tank is used to replace the water within the tank. The result is less energy use as well as an ample supply of hot water. Solar hot waters systems can also use the heat stored for other purposes:
- Heating a pool or spa
- Heating your home
A properly installed system will require little maintenance and has an expected life of more than 20 years. And, a single hot water system can offset the equivalent of approximately 40% of the carbon dioxide emissions of a car. With solar heating systems, you often hear terms such as closed-loop-antifreeze systems, drain-down systems, drain-back systems, recirculation systems, domestic hot water or DHW (sometimes also called solar domestic hot water or SDHW) systems, and space heating systems. Choosing the proper system for your application is determined by many factors. We specifically design systems that fit your situation best.