Geothermal systems are becoming a more popular option in new installations due to the lack of an outside condenser or heat pump, but more importantly due to their uncanny efficiency! Carrier’s line of geothermal heat pump units starts at an incredible 20 SEER with the most efficient unit boasting from 27 to 31 SEER!
If you have already looked over the Carrier air cooled line of air conditioners and heat pumps, you no doubt noticed Carrier has the highest industry rating for air cooled units at 21 SEER; you might be asking yourself, how is it possible for a Geothermal unit to produce 31 SEER. The answer is simple, and can be found in the basic design of a geothermal system.
Instead of utilizing a condenser coil and fan combination of a typical unit to transfer heat into the surrounding air, a geothermal system utilizes a system of pipes buried underneath on your property to transfer heat from the ground, hence the term geothermal. The benefit is simple to understand when you realize that the Earth absorbs almost 50% of the solar energy that hits it and remains between 50°F to 70°F year round. If you have ever been in a cave in the summer months, this concept is easy to understand. The efficiency of the system is magnified by the fact that the Earth is near the perfect temperature year round to operate an air conditioner or a heat pump.
If you are beginning to see the benefit of using the Earth as a heating or cooling source, perhaps you are already ahead of me and are wondering about what happens to the efficiency of an air cooled system on the hottest day in the summer or the coolest day in the winter. Actually, if you are ahead of me, you probably already know the answer, which is that as the outside air temperature goes up, the efficiency and capacity of an air cooled air conditioner goes down, right during the time you need it most. What about air cooled heat pump operation? You guessed it - as the outside air temperature falls, the efficiency and capacity of an air cooled heat pump goes down, right during the time you need it most. How do these swings in temperature affect a Geothermal system? It is not affected! Remember, the Earth’s temperature remains between 50°F to 70°F year round, the PERFECT temperature to operate your system is maintained for you by Mother Earth 24/7/365!
We opened this segment mentioning the popularity of Geothermal in new installations. While it is not impossible to install a geothermal system in place of an existing air cooled air conditioning system, it is necessary to install cooling loops underneath your property for the system to operate. This is typically done through digging straight down similar to a fresh water well or installing the pipe horizontally but still deep below the surface. In either case, a fair amount of earth work is necessary, and this is best done prior to final landscaping as is possible when building a new home. It is not impossible to install a geothermal system as a replacement option, but your Home Comfort Advisor would be best equipped to go over the pros and cons with you.