Geothermal heat pumps have become an increasingly popular option for homeowners in the United States. When a property has this technology supporting its heating and cooling needs, then the pump will circulate a water and anti-freeze solution through buried tubing, referred to as a ground array or loop field, transferring heat between the structure and the ground around it.
Although this technology has been around for several decades, the concepts trace much further back in time. Once you get to about four feet below the surface of the ground, the temperatures stay consistently above freezing levels. Before humans were building homes, they were moving into caves to take advantage of this temperature principle. We use the same approach to transfer geothermal heat into our environment today.
The focus on geothermal energy is due to the fact that it offers a reservoir which is naturally replenished throughout the year. Heat from underneath the soil does not go away unless there are artificial interactions which cause such a result. Even though we use electricity to access this energy, it is more of a renewable resource than wind or solar because the fossil fuel expense is less than the other systems.
Even small homes can benefit from this technology, which is why it is essential to review these geothermal heat pump pros and cons.
List of the Pros of Geothermal Heat Pumps
1. The operating costs are significantly lower for geothermal heat pumps.
Geothermal heat pumps require a low level of energy to operate, even during the winter months. That means the energy costs for a home that is equipped with this technology will be significantly lower compared to the connections from a traditional utility service. Because geothermal energy does not require combustion to create heat, the system will not produce any exhaust during its operation. That makes it one of the most environmentally friendly options that are available for homeowners today.
2. There is no need to install a massive outdoor unit to help with heating.
When your property comes equipped with a geothermal heat pump, then you will no longer need to worry about having a large condenser that distracts from the curb appeal of your home. Because the loops of the system are always buried under the ground, they remain out of sight. The system also runs very quietly, with the indoor unit which supplies the heat making about as much noise as the average refrigerator.
3. You can use this system to heat your hot water tank.
When the cold months of winter are over, you can still use your geothermal heat pump in ways that can save you some money. Many homeowners use this system as a way to produce hot water in their home. Because the pump is pulling warmth from under the ground, your system will work more efficiently than it would if a standard heating element in a tank what is used for this necessity. It is not unusual to experience better recovery times when using this system compared to the traditional design as well.
4. Homeowners save a significant amount of money with this system.
Once a geothermal heat pump is active on your property, then your monthly operating costs will become much lower. You can save up to 60% on your heating bill, as well as up to 50% on your cooling costs when compared to a conventional system. You can install this system with a new construction or retrofit it to an existing structure. The indoor components will typically last up to 25 years, which is 10 years more than most furnaces and conventional HVAC systems. The ground loop on your property is rented to last for more than 15 years. Because the system has fewer moving parts, and it is also protected from the outdoor elements, there are minimal maintenance requires to manage.
5. A geothermal heat pump will usually pay for itself in time.
Even though the cost of a geothermal heat pump is significantly higher than a standard HVAC system, you can still recoup the costs as a homeowner over time. A geothermal system typically costs about 40% more than what you would pay for a traditional setup. Depending on the energy savings that you can achieve once this technology becomes active around your property, it may take as little as four years to have the system pay for itself.
Even when looking at the worst-case scenario for some properties, it may take 15 years to balance out the books. You will want to see what the estimates of this system say for your property to determine if an investment in a pump makes financial sense.
6. It is a system that is seeing extensive growth in the United States.
There are approximately 100,000 geothermal heat pump’s which are installed in the United States each year. The industry is seeing interest levels rise by up to 40% each year because of the cost savings that are possible with the system. Although you will need to stay in your house for up to seven years with a new construction or 12 years with a retrofit to recoup your investment, this option is an excellent long-term investment to consider. It can add tremendous value to your home for prospective buyers in the future. Some homeowners may even roll the upfront costs of the system into their mortgage.
List of the Cons of Geothermal Heat Pumps
1. You will usually need to have a backup heating source for your home.
Geothermal heat pumps can only provide a certain amount of warmth for your home. Because the ground temperatures are typically 55°F or lower, there is not enough availability to create indoor air temperatures that we find to be comfortable during the winter months. That means you will need to invest in baseboard heating, electric heating elements, or a furnace for the days that become really cold in January and February. Although your backup heating source will only kick him during the coldest days of the year, this disadvantage might be enough to significantly cut into your energy savings.
2. There are limited service options in many communities with geothermal heat pumps.
Contractors typically need to carry a specific license or certification to maintain and repair geothermal heat pumps. Because some businesses are unfamiliar with this technology, there may be a limited number of qualified individuals in your area that can work on your system when it requires some attention. Because proper installation of the loop field is critical to the success of the system, your savings will quickly disappear if the work is not done correctly.
You will want to verify all references for any contractor in your area supplying services to geothermal heat pumps to fully protect your investment.
3. These systems are heavily site-dependent.
A geothermal heat pump will only operate correctly if the loop field is correctly situated on the property. It will not function as it should if a homeowner cannot get around this disadvantage. Not every property lends itself to this technology. If you have rocky soil, then a horizontal loop might be challenging to install around the home. Vertical well or slinky loops are possible alternatives, but even they might not be well-suited to some property conditions.
If you have a sizable pond on your property with at least 10 feet of depth, then you can run the loops there because the water will become the source of your stable temperature. The only way to know for sure if your property is ready for this technology is to speak with a qualified installer in your area.
4. The cost of a geothermal heat pump is very high.
Although you can save a significant amount of money by installing a geothermal heat pump on your property, there is an extensive capital cost that you must pay to receive any utility savings. Some systems can cost upwards of $30,000 depending on your plot size, system configuration, soil conditions, and site accessibility. These costs can be even higher if there is a massive amount of digging and drilling necessary for the installation process.
For the typical home in the United States with at least 2,000 square feet, a geothermal retrofit will typically cost between $10,000-$20,000. These costs do not include any modifications that maybe be necessary to your current HVAC system.
5. A geothermal heat pump is not a DIY project.
If you do not have a qualified contractor in your area that can install a geothermal heat pump, then you will need to look out of state or to a different country for the help that you require. This system is not something that even a DIY specialist can install on their property. The most efficient systems always require professional expertise. That means the cost of installation is typically higher in rural areas where fewer contractors are available. Because there is less competition, it may be challenging to get on someone’s schedule. When you do, the costs will be high because there are so few providers out there.
6. Geothermal heat pumps are highly disruptive to your landscape.
The installation of a geothermal heat pump is highly disruptive to the landscaping on your property. On some lots, this disadvantage may make it impossible to install the system. Even if everything goes according to plan, you will usually need to re-plant your lawn, flowerbeds, and any gardens that may be on your property. That is why the best time to install the system is during the construction process. Some homeowners may find that a retrofit would cost more than if they had a system installed when the house was first built.
7. Vertical systems require an extensive amount of depth to be effective.
Most contractors preferred to use the horizontal system with a geothermal heat pump because the installation process is fairly simple. The layered coils or straight runs of polyethylene pipe are put into trenches which are 6 feet in depth. If you have enough open space, then about 400 feet of two-foot-wide trenches can provide you with enough room to effectively heat a 2,000 square foot home.
Vertical systems require a lot of drilling to have a successful installation experience. You can install the system one space is limited, but the holes for the pipe will need to be up to 400 feet in depth to be effective. You will then have two pipes that connect at the bottom of the system to transport the heat into the home.
8. It is not a carbon-neutral system.
Although it is true that there are fewer emissions where is a geothermal heat pump compared to traditional systems, this technology is not carbon neutral. Electricity is still needed to run the heat compressor if you have a closed-loop system installed on your property. This energy resources necessary for pumping of water throughout the entire year in an open loop system as well. That means you will not be cutting out your utility costs entirely. For some homeowners, the savings can be as low as 30%.
9. Geothermal heat pumps work best in heavier soil types.
Because geothermal heat pumps are taking advantage of heat storage and transfer, they typically work better in soils with heavy compositions of rock or clay. If you have Sandy soil around your property, then it will not store or transfer as much heat, which means a larger Bloomfield becomes necessary. Soil moisture can improve the heat transfer by 25% as well, which means dry soils are not well-suited for a direct heat exchange system.
10. You must use anti-freeze to help with the heat transferring process with a closed loop.
Closed-loop systems use water with anti-freeze to create the necessary heat exchange. Older models actually use the methanol for this process, but its toxic nature made its ban necessary in many parts of the United States. You may fund that the ethylene glycol that is found in some anti-freeze products is also against the law to use in your area since it can contaminate local groundwater sources. Brine is useful if you have cupronickel pipes. Most systems encourage propylene glycol since it does not have any known adverse effects on the environment or humans.
11. You must have an adequate flow of water for the system to work correctly.
If your geothermal heat pump does not receive an adequate flow of water, then it will not work as efficiently as it could. This disadvantage can occur if the well which is dug for an open loop system is not deep enough or requires an excessive withdrawal from the aquifer. Sedimentation will clog your filters when there is not sufficient water for the system, which means the use of sprinklers, irrigation systems, and similar products can interfere with your ability to heat the home. Scaling due to lime deposits when there is heavy water can even require chemical treatments to clean.
The pros and cons of geothermal heat pump work to balance the initial capital cost of the system with the savings that temper do this every month for homeowners. If the estimates you receive from your contractor place the cost of installation at the lower end of the median scale, then you have an opportunity to maximize your heating and cooling savings. When the opposite result occurs, then it might be a better idea to wait until more contractors begin offering this option in your area.
Brandon Miller has a B.A. from the University of Texas at Austin. He is a seasoned writer who has written over one hundred articles, which have been read by over 500,000 people. If you have any comments or concerns about this blog post, then please contact the Green Garage team here.