Choosing Between Open-Loop And Closed-Loop Geothermal HVAC System


Few HVAC systems can beat the efficiency and eco-friendliness that a geothermal-based heating and cooling solution offers. Geothermal systems take advantage of the natural heat energy stored in deep within the ground, providing your home with eco-friendly comfort year-round.

Most geothermal HVAC systems rely on ground loops to transfer heat energy to and from your home. If you plan on replacing your current HVAC system with a geothermal unit, you'll need to choose between an open-loop or a closed-loop system. The following offers an in-depth explanation of both types, along with their unique pros and cons.

Pros and Cons of Closed-Loop Systems

Just as the name suggests, closed-loop geothermal HVAC systems feature a completely self-contained loop of flexible underground piping that circulates coolant between the heat pump unit and the ground. Unlike ordinary heat pumps that use R-410a refrigerant as a heat exchange medium, closed-loop geothermal heat pumps capture and transfer heat using fluids that are similar in composition to anti-freeze.

Closed-loop geothermal HVAC systems have a few unique strengths when compared to their open-loop counterparts:

  • Greater installation flexibility. Closed-loop systems can be installed horizontally via trenching to save money or vertically via drilling to accommodate small-sized lots.
  • Fewer worries about water quality. Since closed-loop systems are self-contained, there's no risk of hard water affecting your geothermal HVAC equipment.
  • Fewer worries about water availability. With closed-loop systems, there's little risk of your wells failing to produce enough water to keep your HVAC system operating at full capacity.

However, there are a few negatives to consider when choosing closed-loop systems:

  • Higher installation costs. Installing a closed-loop system can prove costly when compared to its open-loop counterpart, especially when vertical drilling is involved. According to HomeAdvisor, installing a horizontal loop costs $800 per ton, versus the $1,500 per ton needed for a vertical loop.
  • Greater risk of contamination. A pipe leak or rupture could leak rupture leaking potentially toxic anti-freeze into the ground and nearby water sources.

Pros and Cons of Open-Loop Systems

Open-loop geothermal HVAC systems use groundwater in place of the antifreeze-like fluids used by their closed-loop counterparts. True to its name, an open-loop geothermal HVAC system features a loop with inlets and outlets for collecting and discharging groundwater. Open-loop systems pull water from wells, ponds, and other nearby water sources. After circulating through the geothermal equipment, the water is discharged into a separate well or directly back into the lake.

Like closed-loop geothermal HVAC systems, open-loop systems have plenty of strengths that make them appealing over their aforementioned counterparts:

  • Cheaper to install. Open-loop geothermal HVAC systems cost less to install than similar closed-loop systems.
  • Reduced complexity. Open-loop systems require less plumbing than their closed-loop counterparts, making them simpler to install and maintain.
  • More eco-friendly. Without the need for ethylene glycol, calcium chloride, and other chemicals as a heat exchange medium, open-loop systems offer a significantly reduced risk of contamination.

Open-loop geothermal HVAC systems also have their share of caveats to consider, as well:

  • Water quality may affect performance. Mineral deposits from hard water can cause maintenance issues for open-loop geothermal equipment.
  • May require permits for operation. In some areas, you may need state and federal permits to install and operate your open-loop geothermal HVAC system, creating additional operating costs.
  • Not ideal for water-starved areas. Open-loop systems require an ample water supply for optimal operation, making them less ideal for areas subject to drought.

Important Factors to Consider

Before diving headfirst into the world of geothermal HVAC systems, you'll want to consider the following factors that could influence the type of geothermal equipment you end up with. These factors can also have a tremendous impact on your home's overall comfort:

  • Budget - The average geothermal HVAC system costs $3,000 to $8,000 to purchase and install, with some installations topping out at over $20,000.
  • Space - The larger your home's lot, the more options you'll have for geothermal HVAC installation.
  • Climate - Your area's normal climate can also have an impact on geothermal HVAC installation options.
  • Water availability - Lack of a suitable body of water or well drilling issues can limit your installation options.

For more information, get in touch with a local company that offers geothermal cooling system services.


28 September 2018

protecting the outdoor heat pump unit creatively

Your outdoor heat pump unit needs to be protected from the elements. You should have it somewhat covered to keep snow and ice from settling on it and prevent tree limbs from crashing down on it. My blog will show you some creative ways to protect your heat pump unit outside of your home. The protective unit doesn't need to be unsightly by any means. You can come up with several unique ways to disguise and protect the heat pump unit that you will like and will do the job it needs to do for many years into the future.