Tapping into ground heat to warm up a home has been around for some time, but maybe you’ve just started to hear about the benefits of geothermal.
A geothermal HVAC system takes advantage of the consistent heat underground to operate your AC and heater. These systems provide the most energy-efficient means of keeping your home comfortable, and the lifespan of the equipment is longer than for traditional systems.
Ground-source systems have three main components and some optional equipment worth considering. Let’s break down a geothermal heat pump system to understand the parts and how they fit within the system.
The heat pump unit has just a few components to it, all placed in a single cabinet that can go in a closet or attic. Because all of the working parts of the pump are inside the house, they’re protected from any harsh outside environmental conditions.
The compressor is the main part inside the heat pump, moving the refrigerant around so it can absorb heat in some areas and release it in others. Added to that are two heat exchangers, one to absorb heat and one to release it. These can be air-to-refrigerant or water-to-refrigerant depending on the type of system you choose.
Two valves make up the rest of the pump. A thermal expansion valve isolates high-pressure coolant from low pressure, a key step since you need lower pressure so the refrigerant can absorb heat at lower temperatures. A reversing valve allows the unit to function as heater and AC by reversing the flow of energy.
Inside a self-contained unit, you’ll also find the blower, coil, and air filter. If you’re used to a single-speed blower in your traditional HVAC, you’re in for an upgrade with a geothermal unit. WaterFurnace offers two-speed blowers in its 3 and 5 series units and variable-speed blowers in the 7 series to improve efficiency and savings.
The biggest difference you’ll notice from a conventional system is outside as there is no outdoor unit. Instead, geothermal uses a system of pipes running underground to gather and disperse heat. You might see the pipes also called loops since they look like looping coils laid in the ground.
With a closed-loop system, a series of high-density polyethylene pipes are buried in your yard. These are filled with a heat transfer fluid — typically antifreeze and water — that runs through the loops and into the inside unit. The fluid picks up heat from the ground and carries it inside to the heat pump.
The same loop system works for heating and cooling your house as it can carry heat away from the house as well. With everything underground, you won’t experience noise as you might with a traditional outdoor compressor.
The only time the loops will impact your landscaping is during installation when trenches are dug for the pipes. The pipes are deep enough that your prized magnolia tree can cast all the shade it wants without changing the ground temp around the pipes.
Just like a traditional HVAC system, your geothermal setup needs a way to get the air moving around the house. Most of the time, it uses forced air through ductwork, so, likely, you can just retrofit it to work with what you already have in your home.
Geothermal can take advantage of a different method for heating, though. Hydronic distribution involves circulating hot water through radiators or in-floor pipes for heat. For example, WaterFurnace’s 5 Series 500W11 can be used this way in conjunction with a forced-air distribution.
Like any HVAC system, you’ll need a thermostat to control the actual temperature inside your home. A geothermal system shouldn’t need much adjusting, but a smart thermostat can let you get the most efficiency from it by setting schedules based on when you are and aren’t home.
Smart thermostats also allow you to use zoning to get the perfect temp in different areas of your home. WaterFurnace uses its IntelliZone2 zoning system to allow you to connect your unit to up to six zones in the house.
Most geothermal systems are designed with this already in them since it allows us to more optimally size your new system to meet your heating load.
The auxiliary heat helps out the main system during those few really cold days we might get here in South Carolina. It can be an emergency backup heat source if there’s ever an issue with the main system.
Changing out a traditional HVAC system for a geothermal heat pump means learning some new language and parts. Understanding what’s in the main unit can help you with maintenance so you can enjoy geothermal heating and cooling for years to come.
Geothermal HVAC has great advantages for homeowners in the Charleston area, and our team is trained and certified to install the WaterFurnace brand. If you’re interested in seeing if a geothermal system might be right for you, contact us for a free estimate and review of your heating and cooling needs.