this episode is brought to you by brilliant click the link in the description below when building a house homeowners have several ways to power their heating and cooling systems like oil natural gas or electricity but there's another option that's right below our feet you can install geothermal heating and cooling at your home is it worth the cost and how does it hold up i'm matt farrell welcome to undecided [Music] heating and cooling systems are an essential part of our homes but it comes at a cost according to the 2021 annual energy outlook from the eia space heating represents 15 of total household electricity here in the u. s while space cooling accounts for 16 so together they share about 31 of the total electricity use in the country but that's going to vary based on the region along with electricity the main heating fuels are natural gas and oil and while oil usage is low across the u. s it's still sadly widely used here in the northeast where i live and we're talking about 81 of all heating oil is used in this region but thankfully one alternative that's slowly getting steam is using geothermal energy directly from the ground to heat and cool your home if you're interested in how geothermal energy is used to produce electricity i have a video on that topic too geothermal systems have been in place since the 1940s initially providing water heating but with the technologies evolution these systems have been used for different purposes such as electricity generation and heating and cooling systems also known as ground source heat pumps or gshp which take advantage of the ground's stable temperature to provide heating and cooling basically a geothermal heating system is made up of fluid filled tube loops to exchange heat with the soil and a heat pump that removes the heat from that fluid concentrates it and then transfers it to the building using ductwork that part looks pretty familiar to any other forced air heating system that you've probably seen the heart of a geothermal heat pump is made up of a heat exchanger a compressor and a control system that regulates the process the fluid that's used can range from groundwater to a water mixed with antifreeze or another suitable refrigerant that circulates throughout the ground loops but to understand that heating and cooling process it's important to know that heat always flows from a higher temperature fluid or body to a lower temperature one for example when you put an ice cube into a glass of water it melts right that's because the water has a higher temperature and more heat than the ice cube so the heat is transferring into the cube which causes the ice to heat up and melt so taking that back to the heat pump during the winter the temperature underground is higher than the surface air so the cool liquid traveling from the house down inside the loops absorbs heat from underground bringing it back up into the house the heat pump compresses the liquid increasing the liquid's temperature which warms the air and the warmed air is circulated around the house and exchanged with the cooler air the cooled liquid from this process is pumped back into the ground to continue the cycle forming a closed loop in the summertime this process is reversed the lower temperature refrigerant absorbs heat from the house which now has a higher temperature than the underground so it's the exact same principle the heated liquid transfers heat from the house into the ground and returns back up into the house cooled off now geothermal systems can be split up into several subcategories the simplest of which are open-loop geothermal systems they use an open-ended pipe to pump up groundwater which is much closer in temperature to the surrounding ground the water passes through heat exchangers within the heat pump and then back into the ground but this time at a distance from the intake point now this type of system takes a lot of care because you have to make sure that the intake water doesn't damage or clog up the pump or heat exchanger on top of that in some locations there are environmental regulations that require that the output water has to be treated before it's being discharged back into the ground sediment and contaminants from the groundwater can clog up and wear down the system which doesn't happen in a closed-loop system since the refrigerant flows through the loop without actual contact with groundwater all of this makes these systems more expensive to maintain have a shorter lifespan but they do have a lower upfront cost and excellent efficiency closed-loop systems on the other hand are the most common type of geothermal systems for heating and cooling and while not always as efficient as open-loop systems they make up for some of the downsides they can be sub-categorized into four types according to the orientation of the heat exchanger loops in the ground in vertical loops as the name implies they're vertically oriented and they require several holes to be drilled straight into the ground the number of holes their depth the spacing between them and the volume of fluid that's in the tubes depends on the soil temperature variations and the house's heating and cooling needs a great advantage of vertical systems is they can be installed within a very small area horizontal loops just as the name implies here too are composed of pipes that are placed horizontally in the soil with the tubing being buried about one to three meters underground but the length can be up to 120 meters they take up a lot of room if the loops are installed too shallow they can run too cool in winter months horizontal loop systems are usually installed in locations with larger amounts of ground available for digging such as farms country houses like i said you need a lot of space there are also slinky coil loops but not that kind of slinky these are very similar to the horizontal arrangements but they coil the tubing to overlap itself to save space so these loops provide the same distance of piping with less area however these systems require more coiling per kilowatt of capacity and finally pond loops which are submerged systems that are installed in bodies of water near the house these systems don't require drilling or digging which can reduce costs but the water needs to be deep enough so that the loops aren't subjected to surface temperatures geothermal heat pumps are sized in tons one ton corresponds to 12 000 btus and a heat pump with 3.
5 kilowatts of power on average you need 16 to 23 btus per square foot per hour as a standard rule of thumb for heat loss so in a new american house which as of 2020 averages about 2300 square feet it require about 36 000 btus per hour which brings us to a three ton heat pump at around 11 kilowatts geothermal systems have some advantages that have raised interest for homeowners around the world these systems can provide significant savings for heating and cooling they can work well in almost all climates they're environmentally friendly last longer than conventional heating and cooling systems sometimes dramatically longer and require low maintenance according to one market-sized report the geothermal heat pumps market worldwide was valued at 9. 5 billion dollars and is expected to grow at a compound annual growth rate of 7. 2 percent from 2020 to 2027.
the residential sector has been a big booster of that and has accounted for 49. 7 percent of the geothermal heat pump market in 2019 with horizontal loop systems being the most common but like all technology geothermal heat pumps have some drawbacks and challenges that need to be overcome in order to make these heating and cooling systems more commonplace the high up front installation cost is a major stumbling block which ranges from ten thousand dollars to thirty thousand dollars according to energy sage and the larger the system is the higher the upfront cost if you want to get more specific on those prices it's hard because it's going to vary based on where you live and the type of system you're having installed but the ranges and costs for an average open loop system are between nine thousand dollars and fifteen thousand dollars and for closed loop systems you'd be looking at between twelve thousand dollars and thirty thousand dollars and within closed loop systems you have choices between horizontal and vertical loops horizontal being between twelve thousand and twenty five thousand dollars and vertical loops being between fifteen and thirty thousand dollars the low maintenance and lower upfront cost of a closed-loop horizontal system is why they're the most common type sold and these costs are pretty comparable in other areas of the world from what i've seen i found some uk prices that fell pretty much in line with these to put those prices in perspective the average installation cost for a traditional hvac system here in the u. s ranges between sixty eight hundred dollars and twelve thousand dollars including the new ductwork new central air conditioner and a new gas furnace replacing an hvac system without new ductwork costs between forty eight hundred dollars and ninety three hundred dollars depending on the home size and equipment used although the upfront cost of a geothermal system might be higher than a conventional hvac system ground source heat pumps are much more efficient than traditional heating and cooling systems they can achieve a coefficient of performance or cop from three to five which means that for every one unit of energy that is used by the system to power itself it will produce three to five units of heat for the home in addition geothermal heat pumps are certified by energy star at 45 percent more efficient at heating and cooling than a traditional system in canada you might be saving between six hundred dollars and fourteen hundred and forty dollars per year and depending on your current heat source here in the us you can see similar savings the typical payback and savings on the system is usually around 8 to 10 years but keep in mind that these systems have an average 20 plus year life expectancy for the heat pump and around 50 years for the underground infrastructure in many cases the closed loop systems can be expected to last between 50 and 100 years with very little maintenance to reduce those upfront costs government policies and incentives like tax credits and grants have been used to reduce the payback period for example here in the us the federal residential renewable energy tax credit which rolls right off the tongue provides homeowners a tax credit of 30 percent from the total installed cost of the energy star rated system so a twenty thousand dollar system would cost you fourteen thousand dollars after the tax credit on top of that some states also for grants for homeowners who install geothermal systems like maryland which offers a three thousand dollar grant now you're talking about an eleven thousand dollar system and the company dandelion here in the us offers a really simple upfront process of getting geothermal installed in your home they'll evaluate if your home is a good candidate help you take advantage of incentives and provide a no down payment loan so you can start seeing financial savings from day one their surface area is really focused on the northeast us right now but will hopefully continue to expand there's a few other innovations that have been helping to drive efficiency drive down costs and make geothermal more accessible but before i get to that i'd like to think probably the best sponsor i could have had for this video seriously you don't get a better connection with a sponsor than this when it comes to thermodynamics and learning how heat transfers and works brilliance science essentials course can really set you on the right path it really helped me out by the end of the course you'll have a pretty good handle on not just heat but matter and energy as well but if that doesn't get your temperature rising you don't have to stop there because brilliant has over 60 courses on topics like logic mathematics and computer science and yes i made a really bad heat joke they teach all of the concepts through fun and interactive challenges which helps you understand the why of something not just the how it helps to develop your intuition which 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