The new IKEA in Merriam, Kansas, has shoppers and budding interior designers excited, but they aren’t the only ones. Green energy aficionados are happy to see a geothermal HVAC system helping to heat and cool the expansive store. But what is a geothermal HVAC (heating, ventilation and air conditioning) system, and what’s the big deal?
What is a Geothermal HVAC system?
Unlike ordinary heating and cooling systems, geothermal HVAC systems transfer heat to and from the earth using a loop of buried pipes filled with fluid instead of burning fossil fuels to generate heat. Outdoor temperatures fluctuate with the changing seasons, but underground temperatures don’t change as dramatically thanks to the insulating properties of the earth. Four to six feet below ground, temperatures remain relatively constant.
How does a Geothermal HVAC work?
A geothermal cooling and heating system has four main components: a heat exchange pump unit with compressor, a loop of underground pipes, heat-exchange fluid, and air-delivery ductwork.
In the summer, the system passes cool water from the underground pipes across a heat-exchanger before passing it back through the system where it can be re-cooled by the earth. In the winter, the lukewarm water pumped from the underground pipes runs past the heat exchanger and is then compressed, warming it to an even higher temperature, before a fan system distributes the warmth throughout the building.
Why is a Geothermal HVAC a great idea?
- Most geothermal heat pump systems are very energy efficient. Typically, electric power is used only to operate the system’s fan, compressor and pump. For every unit of energy used to power the system, three to five units of equivalent energy are supplied as heat. The system works just as effectively in warming and cooling and can be engineered to require no additional backup heat source.
- It’s low-maintenance. A geothermal system may cost more up front when compared to a more traditional HVAC system, but it requires less ongoing maintenance. Underground pipes — the most expensive part of installation — can last for generations, and the heat-exchange equipment typically lasts decades since it is protected indoors.
- Installation can be flexible. Depending on the site, the underground pipes may be buried vertically, meaning little above-ground surface is needed. If desired, a small backup system can be added for extremely hot or cold days so that the underground pipe system is right-sized for average temperatures.
- It’ll keep going and going. New guidelines and techniques have eliminated the issue of thermal retention in the ground which means heat can be exchanged with it indefinitely. Plus, modern underground pipe systems don’t consume extra water.
So if you shop at the new IKEA store, take a moment to enjoy the air temperature and appreciate the energy-efficient comfort you’re experiencing. And next time you’re looking for an HVAC upgrade at home, consider a geothermal system of your own.