How does GeoExchange work?
GeoExchange harnesses natural heat stored in the ground through a network of underground pipes called a “loop.” A water based solution (refrigerant) circulating though the pipes collects the heat, or geothermal energy, which is passed though a heat exchanger or heat pump, which replaces the traditional furnace and air conditioning system.
How does a heat pump work?
Anyone with a refrigerator or an air conditioner has witnessed the operation of a heat pump, even though the term heat pump may be unfamiliar. All of these machines, rather than making heat, take existing heat and move it from a lower-temperature location to a higher-temperature location. Refrigerators and air conditioners are heat pumps that remove heat from colder interior spaces to warmer exterior spaces for cooling purposes. Heat pumps also move heat from a low-temperature source to a high-temperature space for heating.
An air-source heat pump, for example, extracts heat from outdoor air and pumps it indoors. A geothermal heat pump works the same way, except that its heat source is the warmth of the earth. The process of elevating low-temperature heat to over 37° C (or 100° F) and transferring it indoors involves a cycle of evaporation, compression, condensation and expansion. A refrigerant is used as the heat-transfer medium which circulates within the heat pump. The cycle starts as the cold liquid refrigerant passes through a heat exchanger (evaporator) and absorbs heat from the low-temperature source (fluid from the ground loop). The refrigerant evaporates as heat is absorbed.
The gaseous refrigerant then passes through a compressor where the refrigerant is pressurized, raising its temperature to more than 82° C or 180° F. The hot gas then circulates through a refrigerant-to-air heat exchanger where heat is removed and pumped into the building at about 37° C or 100° F; when it loses the heat, the refrigerant changes back to a liquid. The liquid is cooled as it passes through an expansion valve and begins the process again. To work as an air conditioner, the system's flow is reversed. For more information on heat pumps please visit http://www.waterfurnace.com/faq.aspx?topic=hp
Why is a ground source heat pump a better choice than an air source heat pump?
Air source heat pumps operate at approximately 150% efficiency while ground source heat pumps operate at 300% to 400% efficiency. This means that for every one kilowatt of energy going into the unit, three to four kilowatts of energy are being outputted to heat or cool your new home.
How efficient is a GeoExchange system?
On average, GeoExchange systems cost 30% to 60% less to operate than traditional residential heating systems depending on use. Traditionally, cooling a home would be an additional cost, but with GeoExchange, it is all performed by the same unit.
How long will a GeoExchange system last?
With proper maintenance, the ground source heat pump will have a longer life span than a conventional furnace. The underground piping (HDPE) carries a manufacturer warranty of 50 years.
What maintenance does a GeoExchange system require?
The ground source heat pump will have a filter that will need to be cleaned or replaced, just as a traditional furnace filter would need to be cleaned or replaced. The filter traps pollutants from being re-circulated into the home via the ductwork.
How much space will the ground source heat pump unit require?
In new construction the ground source heat pump will be located in the home’s mechanical (or furnace) room where you would typically see a furnace. The unit size is similar in size to a conventional furnace, if not smaller. The ground source heat pump will perform both the heating and cooling functions for the home.
Can you hear a ground source heat pump throughout the home?
No, the ground source heat pump has a compressor inside that will produce sound equivalent to that of a refrigerator. If you are not in the mechanical (or furnace) room, you should not hear it.
How safe are GeoExchange heating and cooling systems?
The refrigerant (or antifreeze) used in the ground loop system has a low toxicity level and is environmentally friendly. As for the unit inside the home, it is much safer because there are none of the dangers associated with natural gas, including carbon monoxide and open flames.
When the weather warms up, do you have to change a setting on the ground source heat pump to cool the home?
No, you simply set the thermostat to the desired temperature and forget about it. The system will automatically maintain the preset temperature providing year ‘round comfort, regardless of how hot or cold it is outside.
How will the air quality in the home differ from that of traditionally heated homes if heated and cooled by GeoExchange?
GeoExchange systems are the best choice for the indoor living environment. With the elimination of burning fossil fuels, the risks associated with conventional heating such as carbon monoxide or open flames are no longer an issue. Medical, surgical, and research centers that require sterile conditions prefer GeoExchange heating and cooling.
How will heating and cooling with GeoExchange reduce greenhouse gas emissions?
You will no longer be burning a non-renewable carbon based fossil fuel to heat your home. Having a GeoExchange system in your home rather than a fossil fuel burning heating system is equal in greenhouse gas reduction to planting an acre of trees or to taking two cars off the road forever.