The Science of Thermal Energy: Geo-exchange
The science of thermal energy and how it can be leveraged to provide new and green alternatives to meet the heating and cooling requirements of high-rise buildings is evolving fast. Geothermal energy or, more specifically, geo-exchange is one such solution.
In this article we focus on the fundamentals of geo-exchange and geo-thermal heat pumps, and how they can be used as a sustainable fuel source and energy storage solution – improving the energy efficiency, operating costs and security of supply of thermal energy within our cities’ buildings. If you would like to know more about how geo-exchange can provide a win for your building developments, bottom line and the environment, feel free to get in touch.
What is geo-exchange?
Natural Resources Canada ( NRCan) and the US Environmental Protection Agency state that geoexchange is the most energy-efficient, environmentally clean, and cost-effective space conditioning system available on the market today.
How does it work?
Geothermal heat pumps (GHPs), sometimes referred to as Geo-exchange, earth-coupled, ground-source, or water-source heat pumps, have been in use since the late 1940s. They use the constant temperature of the earth as the exchange medium instead of the outside air temperature. This allows the system to reach fairly high efficiencies (300% to 600%) on the coldest winter nights, compared to 175% to 250% for air-source heat pumps on cool days.
An energy-efficient heating and cooling alternative, the geothermal heat pump system moves heat from the ground to a building (or from a building to the ground) through a series of flexible pipe “loops” containing water.
How can geo-exchange be used in buildings?
Geo-exchange systems are optimal for commercial or high-rise mixed use buildings as they 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.
The 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.
Did you know?
- Geo-exchange systems generate virtually no carbon dioxide emissions because they burn no fossil fuels on site.
- High-efficiency geo-exchange systems are on average 48% efficient than the most efficient gas furnaces and more than 75% efficient than oil furnaces.
- Geo-exchange systems outperform the most efficient gas technology, gas heat pumps, by an average of 36% in the heating mode and 43% in the cooling mode. Energy costs with geo-exchange typically are 25 to 50% less than other HVAC systems.
- If every school district in North America that needed to replace a heating and cooling system in the next 10 years decided to install geo-exchange systems, the total energy savings over that time frame would exceed $11 billion.
- The electricity required to power one million homes for one year would be saved if every North American school that could use geo-exchange did so.
How does geo-exchange work using geothermal heat pumps?
Sometimes a picture or in this case a video can paint a thousand words! You can learn more about the fundamentals of geo-exchange using geothermal heat pumps; in this video by US Department of Energy.
With so many questions surrounding thermal energy – the how, what, why, benefits and payback – why not drop us a line? Contact email@example.com.
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The Science of Thermal Energy: Measurement and Management
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Technical insights courtesy of Canadian GeoExchange Coalition – The facts about GeoExchange systems, US Department of Energy – Energy 101 – Geothermal heat pumps video and Energy 101: Geothermal Heat Pumps web site.