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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,
but is it worth the cost and how does it hold up?
I'm Matt Ferrell.
Welcome to Undecided.
(upbeat 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 US,
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.
Now, while oil usage is low across the US,
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 technology's 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 duct work.
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.
The cool liquid traveling from the house
down inside the loops, absorbs heat from underground,
bringing it back up into the house.
And the heat pump compresses the liquid,
increasing the liquids temperature, which warms the air
and the warmed air is circulated around the house
and exchange 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 exchanges
within the heat pump, and then back into the ground,
but this time at a distance from the intake point.
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 systems 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 life span, but they do have a lower,
up-front 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 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 BTU's 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 and is expected
to grow at a compound annual growth rate of 7.2%
from 2020 to 2027.
The residential sector has been a big booster of that
and has accounted for 49.7%
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, upfront installation cost
is a major stumbling block,
which ranges from $10,000 to $30,000,
according to EnergySage.
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 gonna vary based on where you live
and the type of system you're having installed.
But the ranges in costs for an average open-loop system are
between $9,000 and $15,000 and for closed loop systems,
you'd be looking at between $12,000 and $30,000.
And within closed loop systems,
you have choices between horizontal and vertical loops,
horizontal being between $12,000 and $25,000
and vertical loops being between $15,000 and $30,000.
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 US ranges
between $6,800 and $12,000, including the new duct work,
new central air conditioner, and a new gas furnace.
Replacing an HVAC system without new duct work costs
between $4,800 and $9,300 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% more efficient at heating and cooling
than a traditional system.
In Canada, you might be saving
between $600 and $1,440 per year.
And depending on your current heat source,
here in the US, you can see similar savings.
The typical payback and savings in the system is usually
around eight 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 case, the closed loop systems can be expected
to last between 50 and a hundred 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%
from the total installed cost
of the Energy Star rated system.
So a $20,000 system would cost you $14,000
after the tax credit.
On top of that, some states offer grants for homeowners
who install geothermal systems, like Maryland,
which offers a $3,000 grant,
now you're talking about an $11,000 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 service 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 thank probably the best sponsor I could have had
for this video.
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So there are a few other innovations that have been helping
to improve efficiency, drive down costs,
and make it more accessible, like dual source heat pumps.
Some areas of the world are too hot or too cold
for a heat pump to regulate a house's temperature.
Dual source heat pumps can heat,
not just from the underground, but also from the air.
They'll switch to whatever source is the most effective
at that moment, achieving a higher efficiency
than a traditional heat pump.
They're about two to 7% more efficient than air source
and about four to 8% more efficient than just ground source.
Smart controls have also been implemented
to offer support for the grid as well
as reduce their running costs.
If properly synchronized, the smart controls of millions
of devices, such as ground source heat pumps
and electric vehicles would allow the grid
to balance supply and demand.
Smart controls also allow homeowners
to utilize suppliers' dynamic tariffs
or time of use rates, simply running
when the electricity prices are the lowest.
Heat pumps from the British company, Kensa for example,
can be integrated with smart controls
to align heating schedules to periods of low carbon
and low cost electricity.
Tariffs, such as Agile Octopus for example,
publish half hourly electricity prices a day ahead,
therefore the smart controls will vary those prices
and synchronize them with the household's usual routine,
providing the homeowner with lower running costs.
Geothermal heat pumps may not be the first pick
for the average homeowner who isn't thinking long-term
for the environmental benefits, but with further refinements
and incentive policies, geothermal systems will continue
to become a more compelling choice for the masses.
What do you think?
Do you want a geothermal system?
I know I do.
Jump in the comments and let me know.
If you like this video, be sure to check out one
of the ones I've linked to right here.
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if you think I've earned it and, as always,
thanks to all of my patrons and to all of you for watching.
I'll see you in the next one.