When most people think of geothermal heating systems they think of endless digging in the back yard to put a bunch of pipe in the ground to “hopefully” save money on their utilities (this is almost a sure bet, if done properly by the way). However, most people aren’t exposed to how versatile these systems can be. There are lots of creative solutions available now because of geothermal energy. Geothermal can be an all encompassing solution for homes (heating, cooling, water heating, etc.) but they can also be a complete solution for larger commercial projects (schools, hospitals, government buildings, churches, etc.). This article will highlight several potential applications of geothermal systems that you might not know are possible.
Single Zone Heating
This is the prototypical residential installation configuration. It’s one single heat pump that serves conditioned air to many rooms. In a house, it’s (typically) the same heat pump that heats and cools the room in the far corner of the upstairs as the living room. The point here is not those particular rooms, it is just that a single heat pump, controlled by one thermostat, controls everything, even those rooms with different use and exposure.
Multi Zone Heating
For larger houses or commercial applications, it is advantageous to connect several heat pumps to the geothermal loop. Not only can you do effective zoning (grouping rooms with similar use on a single heat pump), you also have the diversity of multiple units powering on and off depending on the load. Putting more heat pumps in a building gives better control and comfort. You also save significant energy by not powering all the heat pumps at the same time.
Still not clear? Think of a typical school. There are a certain number of children, staff, computers, and lights contributing to how much heating and cooling is needed. When a full classroom of kids are in the classes, this area can have a heat pump operating. At this point the heat pump(s) in the cafeteria need not be used. When several classes go to eat lunch, it’s vice versa. In an office building it is typical to have several offices on a heat pump, but have the company conference rooms on another. This provides the same benefit. The more heat pumps, the more widespread the comfort, and the more diversity with how much equipment is operating at a given time.
Geothermal Central Plant
For very large applications, a geothermal central plant is a good option. In most commercial buildings there is a room that houses substantial HVAC, electrical, plumbing, and fire protection equipment. This used to be called the boiler room, because the de facto HVAC system type involved boiler. They were such massive pieces of equipment they often required huge rooms dedicated to their service. “Central Plant” is the more appropriate term for what is (often mistakenly) called a “boiler room.” There are ways to adapt these rooms and systems to geothermal.
A geothermal central plant involves equipment that serves a similar purpose to the equipment in a house but is more powerful. Heat pumps are replaced by larger heat pumps or large air handling units. Heat pump water heaters are replaced by heat pump chillers, capable of producing chilled water for air handlers or hot water to replace boiler usage. This is a very detailed process, so input from engineers and manufacturer’s representatives is required.
Auxiliary Heating
If you are concerned about your geothermal heating system and want to hedge your bet on the new technology, or simply want to have “backup” heating, you’re in luck. Most heat pumps come with optional supplemental heating coils that provide auxiliary heating capacity. What this means is an extra heat exchanger is added to the discharge side of the heat pump. That way if you are dissatisfied with the heat output of the heat pump, you can supplement it with electrical heat or a gas powered furnace coil.
You will cut the efficiency of the unit a slight bit by adding this extra coil, but if you want the peace of mind, it’s an option. For an application like a storage unit this is a good option. It provides the safety of keeping a space above freezing temperatures, and gives a backup option if the geothermal doesn’t have the necessary capacity.
Special Zone Heating
Defining a “special zone” isn’t exactly easy, but it is important to know that there are geothermal heating options for the parts of a building that don’t fit the cookie cutter “office” or “classroom” label. Small terminal geothermal units are available for rooms like vestibules and stairwells. These rooms are typically cold from having leaky drafty doors because they are opened and closed constantly. They also are on the extremities of the building, making it hard to attach them to infrastructure.
Other special areas are not commonly trafficked, but have important purposes. Mechanical rooms and sprinkler rooms have very important equipment in them that must be protected. Although these rooms do not typically need to be air conditioned, it is extremely important that these rooms do not get too cold. Equipment begins to malfunction and water freezes at lower temperatures, both of which can be catastrophic to the performance of your building.
Radiant Floor Heating
Once a luxury to only the very rich, radiant floor heating is fast becoming something people splurge on when buying a home. Running water through small pipes just beneath hardwood and tile flooring provides the opportunity to provide a warm floor, and often times it can satisfy the entire heating demand of a home in more temperate weather. Since heat naturally radiates upward, geothermal radiant floor heating is becoming a viable replacement to the baseboard mounted convectors seen in older homes in cold climates.
Speaking of cold climates, in really cold climates lots of snowfall and ice accumulation can be dangerous to people. Radiant floor systems can also be installed in sidewalks and driveways to melt snow and ice at the edge of your home or workplace. This provides safety to pedestrians, and is becoming more and more used because of geothermal.
I hope this overview has shown you that there are several possible outside the box applications for geothermal heating systems. The efficiency of these systems are high enough that adding these variations of the traditional heat pump help make geothermal a widespread solution to your needs.