With soaring energy prices and ever-increasing summer temperatures — homeowners face the age-old dilemma — to cool or not to cool? Are more comfortable — not to mention safer — home temperatures worth the every-climbing bills?
What if the answer was actually… right below our feet?
I’m talking about Geothermal Heat pumps, and I think they’re about to become the next big thing in residential heating and cooling! Here’s why!
If you follow our channel – don’t forget to subscribe by the way — you know how much I LOVE how insanely efficient heat pumps are! So imagine how excited I am that Geothermal or Ground Source heat pumps can take those levels even higher… ironically by taking the technology… lower!
Like all heat pumps, geothermal models have three main components — the heat pump unit, a liquid exchange medium, and a distribution system. The main difference is that Geothermal ductwork runs in loops between four and ten feet underground where the temperature almost always remains between 50 and 55 degrees F. That’s a critical factor we’ll explore later.
The important thing to know for now is that, pretty much everywhere in the world, there’s almost always a heat differential between the air and the ground. Heat pumps work based on thermodynamic principles that say heat always travels from high temperatures to low temperatures.
So, when winter air temperatures are lower than underground, the working fluid absorbs that ground heat energy and pumps it into your house.
During the summer, the process is reversed, pulling heat out of your home and putting it either back underground, or channeling it to your water heater or other home appliances. sources.
Geothermal heat pumps come in a few varieties. The two biggest categories are open-Loop systems — which do not circulate water but deposit it into drainage after use — and Closed-Loop systems which circulate a mixture of anti-freeze and water. We won’t dive into the different varieties here, but my buddy Matt Ferrel has a great breakdown if you want to check out his video after this one!
Like other heat pump technology, geothermal units have incredibly high coefficiencies of performance.
High-efficiency gas furnaces have COPs around 97% . But, standard furnaces hover around 80%. So for every 100 BTUs of fuel your gas furnace consumes, it only produces 80 BTUs worth of heat. BTU or British Thermal Unit, refers to the amount of energy it takes to increase the temperature of a pound of water by 1 degree F. Aaaanyway. An 80-97% efficiency isn’t bad, but it does mean you’re losing some efficiency.
Ok — so what about electric heaters? Well, if you remember from my previous heat pump videos, electric heaters have COPs pretty close to 100%, meaning they consume energy and produce heat at a near one-to-one ratio. And that’s great. BUT, as of 2020, according to a survey by the EIA, only about 37% of Americans supplement their main heat source with electric heaters.
A staggering 41% of Americans still use natural gas as their main source of heat, while another 8% rely on petroleum.
In optimal conditions, air-source heat pumps can reach COPs of 300, 400, even 500%!
BUT — one major advantage ground source heat pumps have even over air source heat pumps — is consistency.
See — while air source heat pumps are generally the most efficient, their efficiency hinges on outside air temperatures. They actually tend to work best when the outside air temperature stays around 40 degrees F.
When the temperature falls below that 40-degree mark, heap pumps start losing efficiency. And when the air gets really cold — below 25-30 degrees — they actually lose their spot as the most efficient heating option.
This is where geothermal heat pumps really begin to shine! Remember earlier when I said the temperature below ground stays consistent! Here’s why that’s important!
No matter how wild the air temperature varies, underground temperatures stay between 50 and 55 degrees F. Always! No matter how grueling the winter gets, a geothermal heat pump will almost always work at its maximum efficiency. And just how efficient?
Depending on the system, geothermal heat pump COP can range between 300 and 600% — making them significantly more efficient than gas or electric heaters, and, at worst, comparable to air-source heat pumps. But factoring in their consistency, ground source heat pumps are generally the most efficient way to heat things up!
So why should these numbers matter to you? Because efficiency equals money in your pocket! We’ll break down exactly how that works in a second, but first [insert sponsor here]
For the average person living in the US, over half of your annual energy bill goes toward heating and air conditioning!
Most people favor natural gas because, on paper, it seems significantly cheaper than electricity,
Gas is measured in therms. One therm equals 100 cubic feet of gas, or 100,000 BTUs, which is the same as about 30 kWh of electricity. So, hypothetically, if one therm cost 60 cents, electricity would have to cost roughly 2 cents per kWh to be comparable. But even in Louisiana, which has some of the lowest electricity rates in the country, they still pay roughly 7 cents per kWh. Feel free to pause the video if you need to let your brain cool off!
While prices tend to vary by region, generally, with all factors considered, natural gas prices are two to three times lower than electricity prices.
But, with other mitigating factors like dwindling supply, blossoming demand, a global pandemic, and geopolitical turmoil, Natural gas prices for the 2021-22 winter heating season have exploded — upwards of 50% higher than last year across the country!
But electricity ain’t cheap either. This means to replace gas, we’d either need cheaper electricity, OR more efficient technology! And that’s where geothermal heat pumps could have a massive advantage!
So let’s take a look at this in the real world. Let’s go someplace with a frosty winter like… North Dakota, where Natural Gas currently costs around $0.32/therm.
The annual energy cost for the average household using a Natural Gas furnace with 95% efficiency comes out to roughly $436. An air-source heat pump at 160% seasonal efficiency racks up around $613 annually.
A ground source heat pump, operating with a 350% COP — $233 annually! That’s almost half the cost of natural gas! Where did these numbers come from?
This graph… on the Montana-Dakota utility website… the company that provides natural gas to four of the coldest states in the US.
Now — you may have noticed one column blurred out. That’s on purpose and we will get to it in a second.
[When you show this graph — have the right column “installation costs” blurred out]
But just look at the difference in annual cost! According to the EPA, a ground source system can reduce energy consumption by more than 40% compared to air-source heat pumps, and over 70% compared to standard heating and cooling! This can mean 30 to 60% off heating costs!
But what about here in California where we’re less concerned about frigid winters and more concerned about melting on the sidewalk like we’re in Raiders of the Lost Ark?
Well, geothermal has an edge there too — 20-50% off cooling depending on the size of your home and the system you use.
So while natural gas may still be the cheaper fuel (at least for now), it doesn’t really matter when you’re using a system that is significantly more efficient.
And if that weren’t enough — because these systems don’t actually burn any fuel AND they use grid energy much more efficiently, they’re also a much better choice for the environment!
Today — heating and cooling account for roughly 10-20% of total greenhouse gas emissions in the US. One of the largest contributors to the residential sector behind transportation.
A ground source heating and cooling system can reduce your household emissions by between 75 and 85%!
Now, as I mentioned, one column on that chart was conveniently blurred out. Here’s where we get to some of the tougher truths to consider before deciding if one of these systems is right for you.
One major consideration is the installation cost.
The average HVAC system, including ductwork, will cost anywhere between $5,000 and $10,000.
A new gas furnace and ductwork can cost between 2 and $6,000 — making them among the cheapest to install upfront.
Air source heat pumps can cost between $10,000 and $20,000 to install, and ground source heat pumps… yeah… they can range anywhere from $12,000 to $30,000.
And That’s if you even have space for a ground source heat pump. An 11kW horizontal system would require three ground loops, each about 200 meters in length. Each loop laid in a rectangle with 1 meter of separation between them — resulting in a larger rectangle 7 meters in width by 100 meters in length — meaning you’d need roughly 700 meters sq. in total. The larger your system, the more space required.
Now, there are vertical loop systems that require less space but more equipment for drilling deeper holes. These boreholes can run about ¼ meter across and up to 100m deep! These systems can be more efficient since they run deeper where ground temperatures are even more consistent, and they also don’t require as much open space but can be more costly due to more complex installation.
Still, while those upfront numbers might look scary, don’t go running for the hills just yet. As always, when we dig into the numbers there’s more to the story.
For instance, in the US, both state and federal incentive programs can provide homeowners with tax credits up to 30% off the total installation cost of Energy Star-rated appliances. So now, a $20,000 system costs $14,000.
States like Maryland offer grants up to $3,000 for energy-efficient installations — bringing the cost down to $11,000.
Then there’s the longevity of the systems. While gas furnaces might be less expensive upfront, they tend to last between 15 to 20 years. Traditional HVAC systems can last up to 25 years. Geothermal systems? A closed-loop system can last up to 50 years, with ground components lasting up to 100 years! And, between incentive programs and overall savings on heating and cooling, geothermal systems can be fully paid off in between 8 and 10 years!
So while the cost may be higher upfront, it can still save you more money in the long run.
But where these systems could really shine is in new home builds. in fact, one of our viewers in Austin Texas lives in a planned community where every home being built has geothermal.
One of the main reasons most homes in the US DON’T already have ground source heat pumps is because, really, the technology didn’t exist when most homes were built, at least not in a way that could be so widely applied. But that all may soon change. And adding one to your home may not only save you money in the present, but it could also very well add significant value to your home as many homeowners and consumers begin to think beyond fossil fuel!