Residential Geothermal HVAC
A geothermal heat pump has many of the same components and characteristics as a standard heating and cooling system, but without the high utility bills, drafty air, and loud, obnoxious outdoor equipment. The installation of the system, however, is different. When it comes to geothermal HVAC system installation in Maryland (or any other state for that matter), there may be some digging or drilling involved. Careful planning is required to install a geothermal system correctly, which is why it’s important to use a Maryland HVAC company experienced in such projects.
Residential Geothermal HVAC Installation
Standard ductwork is run from your air-handling unit placed either in the attic or in the basement of your residence. Vertical or horizontal wells are then drilled outside of the home, and polyethylene piping is inserted into the holes or trenches. All the piping joints get fused together using hot irons and routed to the inside of the home near the actual geothermal unit. Piping then enters what is called a pumping station that pushes and pulls the water through the underground loop, as well as the refrigerant loop located in the equipment. The “closed-loop” is then purged with freeze-resistant water. Lastly, a thermostat is connected, and heat or cooling is produced upon demand.
Types of Residential Loops
The loop pipes that carry the water and antifreeze mixture underneath the ground can be arranged in different ways. Here are the four most common types:
This type of loop system is generally the most cost-effective option for residential installations, especially for new construction where sufficient land is available. This type of system is installed within trenches that are between four to seven feet deep. A series of plastic pipes are laid inside of the trenches and connected to the heat pump. A typical horizontal loop will be 400 to 600 feet long for each ton of heating and cooling.
Vertical loop systems are commonly used for commercial buildings or buildings with limited space. It starts by drilling vertical holes in the ground that are anywhere from 150 to 400 feet deep. Then, a single loop of pipe with a U-tube at the bottom is installed. The hole is then sealed with grout to ensure adequate contact with the soil. Lastly, the vertical ground loops are connected to a horizontal underground header pipe that is responsible for carrying fluid to the unit.
If a building is located near a body of water, a pond/lake system may be the most economical choice. A supply line pump is run underground to the body of water and is coiled into circles at least eight feet underground to prevent freezing. In order for this type of system to work, it must be placed in a body of water that meets its minimum volume, depth, and quality criteria. It’s important to note that pond/lake loops have no adverse impact on the aquatic environment.
This type of system is only possible if there is sufficient groundwater available via a well, lake, or river. The water source must be of good quality and comply with local groundwater discharge codes. Since the system is open, a water pump is placed directly into the geothermal unit and then discharged into a return well or a body of water. The system does not affect the water’s quality.
What to Expect from Your Geothermal System
Installing a geothermal system in your home comes with plenty of benefits.