Geothermal heat pumps are an amazingly comfortable, efficient, cost-effective and environmentally friendly heating and cooling source. If you’re considering a Nordic geothermal heat pump for you home, you’ve likely got more than a few questions about how you’ll benefit, what you can expect, and how the installation process works. We’ve compiled the answers to some of the most common questions we are asked. Read on to learn about using geothermal heating and cooling in your home.
What is geothermal heating?
The Earth contains a vast amount of thermal energy, even within the upper crust. Geothermal heat is the heat that is derived from both the Earth’s own internal temperatures and solar heat energy that is stored in the ground. The earth’s upper crust, the lithosphere, maintains a constant temperature, with temperatures increasing up to 1,000°C as depth decreases further down this layer. At the Earth’s core, the temperature is estimated to be 6,000°C. Geothermal takes advantage of this heat on a very small scale, at the very outer layer of the earth’s crust.
Geothermal heating and cooling systems are an efficient and clean way to harness the environmentally friendly, renewable heat energy from what already exists in the Earth, keeping your home at a comfortable temperature on a year-round basis. Anybody who has been to a hot spring has seen first-hand the incredible heating power of the earth—why not harness this incredible resource to heat our homes?
Why choose a geothermal heat pump?
Geothermal heating and cooling systems provide comfortable, consistent temperatures all-year-round at the touch of a (thermostat) button. You do not need to worry about oil tank maintenance or leaks, stacking firewood, or vacuuming out registers. The only maintenance required is the periodic changing of air filters if you have a water to air heat pump. And because the geothermal heating and cooling you’ll enjoy with a Nordic heat pump is a non-combustible energy source, drapery-staining smoke and soot like you’d experience with a wood stove or fireplace will never be an issue in your home.
Geothermal heat pumps are robust and durable—regardless of climate. Because the components of the geothermal heating and cooling system are installed either indoors or underground, they’re not visible on your property, aren’t vulnerable to vandalism or wear and tear from the weather, and can’t be blocked off or impeded by large snowfall amounts.
Conventional energy sources like oil, natural gas, coal or wood heat burn fuel in order to create heat and are not 100% efficient which means that some heat is lost up the flue. With traditional heat sources, your home never gets 100% of the possible heat energy that the actual fuel contains. Geothermal heating does not need to burn anything to create heat because it distributes heat that already exists.
Because geothermal heat pumps are simply moving existing heat from one place (the ground) to another (your home), the heat itself is free. The only electricity used is that required to run the heat pump. What this means is that for every 1 watt of electricity that is used to run the heat pump, 4 watts of heat energy are harvested from the ground. This means geothermal heating and cooling is 400% efficient which means that you don’t need to worry about lost potential heat.
Unlike other renewable energy sources like solar or wind energy, geothermal energy is not adversely affected by the weather. Whether it is cloudy, sunny, windy, still, or snowing, your geothermal heating and cooling system will continue to consistently and efficiently keep your home comfortable.
Thanks to the efficiency of Nordic’s geothermal heating and cooling system, these heat pumps can be a great choice for your family’s budget. Once the system is installed, the only ongoing operating cost is for the modest amount of electricity used to run the pump while it captures the heat beneath our feet. As the Earth’s heat is free and sustainable, it is not subject to the ups and downs of the global economy. In fact, geothermal heating and cooling systems can reduce your heating bills by up to 75%!
How does it reduce your costs? Here is an example:
Imagine your house is 1,750 square feet and is heated solely via electric baseboards. Electric baseboards are 100% efficient, meaning that 1 watt of electricity consumed generates 1 watt of heat energy. It’s estimated that your home is consuming 120 kwh per square meter, per year, for a total heat load of 21,000 kwh per year. Using a local utility rate of $0.16/kwh, that results in a total annual heating bill of $3,360.
As stated above, geothermal heat pumps are 400% efficient, so one watt of electricity is required to harvest four watts of heat energy. Your heating needs don’t change, but you will require 75% less energy to obtain that heat. So instead of using 21,000 kwh per year, you would use 5,250 kwh per year. Keep the same electricity rate, and you have a total annual heating bill of…just $840.
How geothermal is used in homes
A geothermal heating and cooling system harnesses the constant temperature of the upper crust of the Earth’s surface and uses it to heat a home in the winter. It is also able to reverse the process and extract heat from your home and transfer it back to the relatively cooler ground in the summer, acting as your air conditioning system.
How do the heat pumps do this?
There are three components to the geothermal heating and cooling system: the energy supply source, the heat pump and the energy distribution system.
The energy supply source is also known commonly as the ground loop. The ground loop consists of plastic piping buried in the ground, in either a horizontal or vertical pattern. The ground loop harvests heat from the ground via fluid circulating through the plastic tubing, which then absorbs the ground’s heat and carries it up to the heat pump.
The geothermal heat pump is where the heat energy from the ground becomes the heating for your home. The heat pump extracts the heat energy that was absorbed by the fluid in the ground loop and concentrates it into usable heat energy, using its compressor. From there, the heat pump transfers the concentrated heat energy into the last component: your energy distribution system.
The energy distribution system is the process of how the concentrated heat is distributed throughout your home, keeping you and your family warm and comfortable. The two distribution systems that are compatible with geothermal heating and cooling are ductwork (forced air) or radiant in-floor heat. The geothermal heat energy can also be integrated into your hot water heater, providing your family with hot showers and baths at a fraction of the traditional energy costs.
Choosing a Geothermal Heating and Cooling System
Choosing an energy distribution system for your geothermal heating and cooling system is, fortunately, one of the easier decisions you will make as a homeowner. Your decision will depend upon the age of your home, if it is already built or is under construction (or under renovation), and how many levels it has.
The two major energy distribution systems that are compatible with your geothermal heat pump are radiant underfloor heating systems and forced air ductwork. Your geothermal heat pump model will be determined by which energy distribution system you use.
Under Floor Heating
If you are considering a geothermal heat pump for a new build, or if you are preparing to replace your existing flooring, an in-floor heating system (also known as radiant heat) is likely your best option. Some newer homes already have underfloor heating systems installed, making it simple to uninstall the existing source of heat and attach the geothermal heat pump to the underfloor heating system.
Radiant underfloor heating works via polyethylene piping that is installed beneath your floors. Liquid, generally a mixture of water and antifreeze, is warmed by the geothermal heat pump, and is then distributed in a closed loop throughout the tubing. As the fluid travels, it makes its way back to the geothermal heat pump to be reheated, resulting in a continuous flow of heat under the floor, and under your feet. This heat then rises to warm the entire house.
Many older or two-story homes have forced air furnaces, which blow heated air throughout the house via ductwork. The air is heated with an oil, natural gas or wood furnace. To install a geothermal heating and cooling system in these homes, the heat pump system would replace the existing furnace, blowing heat throughout your home’s ductwork.
The heat pump system will differ from the furnace in that it will not require regular maintenance except for air filter changes. You do not have to buy oil, stack firewood, or pay for chimney cleaning. Further, because the geothermal heat pump system uses lower temperature hot air, you’ll be more comfortable. The output temperature of geothermal heat is lower than with traditional furnaces, but the air volume is higher to compensate. This high volume/low-temperature combination eliminates heating inconsistencies in the home, such as having one side of the room too warm because that’s where the register is, and the other side too cold. With geothermal heat, the whole home is one consistent, comfortable temperature.
After with heating your home, heating domestic hot water is the second largest use of energy in your home. Between washing our laundry, our dishes, and ourselves, hot water is a necessity in our homes, and often, an expensive one.
Your Nordic geothermal heat pump can be connected to your hot water heater, simply by choosing a unit with a “desuperheater”. Whenever the geothermal heat pump compressor is running to heat or cool your home, the water from your hot water tank is circulated through the desuperheater and is heated by the hot refrigerant circuit inside the heat pump. In most cases, your Nordic heat pump will raise the temperature of your domestic hot water up to 60°C without any extra expense, greatly reducing the demands on your hot water heater.
When the geothermal heat pump is not running, your hot water tank would simply function as before, using electric heaters in the hot water tank to heat the water.
Choosing a Loop
The energy supply source, or “ground loop” is a key step in your heat pump installation. This ground loop will be the conduit that draws the heat from the ground and then brings it into your home. There are three primary types of ground loops, and the type that will work best for you is dependent entirely upon your property and its features. If you need help deciding which type of ground loop will work best for your property, your geothermal heat pump installation specialist can make a recommendation.
Open Loop System
An open loop system harvests heat from ground water. This is achieved by pumping water from an “entering” well to your heat pump, which then removes and compresses the heat, and rejects the cold water back into a second “rejection” well.
The temperature of the water in the entering well is at least 4.4°C or warmer, depending upon where you are located. The heat pump extracts that heat and returns the used water to the ground through a second “rejection” well, about 3 degrees cooler than before. Once the cool water is returned to the aquifer, it is recirculated, reheated, and reused. No chemicals are added to the water. The heat pump simply takes heat out of it, again and again.
If you already have a well on your property with a substantial flow, this is the least expensive method of providing a source of energy for your heat pump. Be sure to check with your local municipal office prior to starting any drilling project to ensure it is in compliance with regulations in your area.
Horizontal Loop System
A horizontal system is known as a “closed loop” system. The system is completely sealed and will not leak or interact with the ground water in any way. A horizontal ground loop system uses high-density polyethylene piping buried in a pattern, six feet deep in horizontal trenches. These pipes are then filled with fluid that will absorb the ground’s heat.
Small pumps then move the loop fluid from the ground to your geothermal heat pump, where the heat is removed and compressed, and the fluid is circulated back out into the loops to be reheated. In the summer, the process is reversed, with excess heat from the house being removed and deposited into the relatively cooler ground.
Vertical Loop System
A vertical loop system is also a closed-loop system, and works in an identical fashion to the horizontal loop system. The only difference is that instead of trenches, the system uses drilled vertical boreholes.
Two plastic pipes joined together by a U-bend at the bottom are inserted into each borehole. Most residential installations require anywhere from two to six boreholes. Vertical loops take up much less surface space than horizontal loops, making them an excellent choice for smaller city lots, or anywhere that space is more limited.
Considerations for installing a geothermal heat pump
As always, before planning any project that requires digging, be certain to contact your municipal office for the required permits, and also to ensure that there are no gas or water lines that may be present.
The system used will depend heavily on your property’s characteristics. Property size, current land use, and what kind of material is below the surface (clay vs. bedrock, for example) must all be taken into consideration.
Be certain to carefully note the location of your heat loop piping, especially if you plan on selling your home, so as to avoid inadvertent damage via future landscaping projects.
Taking measurements for the system
Open loop system: A geothermal well is typically five or more inches in diameter, so as to be able to accommodate a submersible pump. The water flow enters at a depth of at least 75 feet, to ensure a continued flow of water even in dry weather. The well must have enough flow to accommodate the heat pump and the residential water usage, with a minimum of 30 psi at the well’s dynamic pumping depth.
Closed loop systems: With a horizontal loop system, each horizontal trench is 250 feet long, four feet wide and six feet deep. Once all trenches are dug, a 500-foot roll of ¾” pipe is installed. Approximately half an acre of available land is required to accommodate the trenches. For vertical loop systems, anywhere between two to six vertical holes are drilled. The boreholes are typically four to six inches wide, and between 150 and 300 feet deep.
A Nordic geothermal heat pump is a fantastic investment that provides environmentally friendly, long-lasting and—most importantly—comfortable heating and cooling all year round. Don’t wait any longer to discover how much you’ll save and quickly you’ll see the benefit. Find a dealer today!