Photograph via snooOG

A reddit focused on geothermal energy and geothermal electricity. All civil discussions aren't just welcome but wanted.

The Geothermal Reddit

Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. The Geothermal energy of the Earth's crust originates from the original formation of the planet (20%) and from radioactive decay of minerals (80%). The geothermal gradient, which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface. The adjective geothermal originates from the Greek roots γη (ge), meaning earth, and θερμος (thermos), meaning hot.

Wikipedia: geothermal energy

Geothermal electricity is electricity generated from geothermal energy. Technologies in use include dry steam power plants, flash steam power plants and binary cycle power plants. Geothermal electricity generation is currently used in 24 countries, while geothermal heating is in use in 70 countries

Wikipedia: geothermal electricity

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3,401 Subscribers


Climate Master Tranquility 30?

We are considering a quote for a Climate Master Tranquility 30 geothermal system. There aren't a lot of online reviews for CM, but the ones I found are pretty bad. We like the installer and the price is comparable to the other quotes we got. Does anyone have personal experience with Climate Master geothermal products? I appreciate any feedback, good or bad. Thank you.

20:50 UTC


It’s finally here

09:34 UTC


Electric Water Heater Tank

Hey folks, wondering if I can get some help or pointed in the right direction

Purchased a home a few years ago that has a Nordic geothermal heat pump, provides heat via in floor heating. I know the basics but am by no means an expert.

We live in Canada and have an electric water heater tank thats now 15 years old and a couple times in the past month we have been running out of domestic hot water (shower, taps etc). No signs of rust or leaking

My question is, if I was to replace it, do I need a specific type of electric water heater tank for my geothermal system or would any type work. I'm currently using a Superstor Solar water tank (60gal) SSU-60SE (not sure why this unit is being used as there are no solar panels in use)

Also, any recommendations?


00:04 UTC


Geothermal Radiant Floor Heating, AC, and air filtration

Looking at building a new house with radiant floor and hot water geothermal heating. I suspect to avoid condensation on the floors I also need ducting to support forced air AC for the summers as well as air filtration/circulation year round. Anyone augmented geothermal hot water with a solar hot water setup? Not sure the cost makes sense to install all the ducting and radiant floors. What is usually done to do radiant floors and AC? Plan on doing a closed loop geothermal to reduce maintenance costs from hard water.

22:05 UTC


Question about displaced HVAC systems

Hello all,

Just curious, for those of you who have displaced your fossil fuel heating system; what happened to the equipment that was displaced?

We're planning to replace our oil system with a geothermal one, and the oil boiler is pretty high-end with years still left on it. Additionally, we'll potentially have a decent amount of oil left in our tank, which definitely has value.

I can't imagine that folks just scrap this, so what's the protocol here? Is there a market for used HVAC equipment that was displaced but still has value? I imagine the oil companies will reclaim the leftover oil; do you get compensated for it?

18:49 UTC


Duct Sizing for Geothermal and Noise

I'm getting a 6-ton geothermal system installed and was wondering about duct sizing and noise. Current ducts are 20" x 8" to the downstairs and 24" x 8" to the upstairs (larger sq footage upstairs). I know geo systems tend to push air at higher CFMs than standard oil based systems due to lower supply air temperatures. Has anyone had experience with the geo system creating excessive noise thru the ductwork of their home due to this effect?

16:02 UTC


Radiators and aircondition with geothermal

I have a rather odd situation. I want to install geothermal, but my house currently has two systems; radiators and then air conditioning that was put in years later. The air condition is only on the main floor and does not go into the basement.

My question is is there a way to use the geothermal for both systems or would I have to switch over to using only forced air to both heat and cool the house?

Part of the reason I would like to keep the radiation system is that I a) like radiators and b) there is no duct work into the basement so new duct work would have to be added through the main level somewhere to go to the basement otherwise it would get tool cold.

01:33 UTC


For a small house (200 m3) how long should the pipes run for (for COOLING)?


I am new to Geothermal cooling and heating and here in my country there is no way to get information or find people who worked with Geothermal Open (or closed) loops

I am building a small house 60 m2 and 200 m3 (for BTU calculation) and I am considering:

  • 50 meter long 200 mm pipes (straight line)
  • 4 meter deep
  • Open Loop (the inlet will be surrounded by trees and shade)
  • AC infinity In line fan (centralized in the center of the house, with ducts distributing the air)


  • Even without a heat pump, will the system keep the house cool? (Average temperature outside varies between 8C and 29C during the year)
  • Will the pipes stand 4 or more meters of humid soil on top of it without collapsing?
  • How thick should the pipes' walls be? as I think there is a trade-off between resistance and how well it transfers soil temperature to the air flowing in it.
  • Can the pipes be horizontally aligned, or SHOULD I add some gradient to it (if so, how much? 2%, 4%?)

As you guys can see, I am completely clueless, but I am trying to learn. so maybe this will become one of the first well-designed systems in my area and I would be a “poster boy” for geothermal systems around here and help other people.

Any help will be appreciated.


20:53 UTC


Small, cheap DIY Ground Source Heat Pump project in Toronto

Ground source heating is great but installation costs are high. I decided to see if a cheapo do-it-yourself system could provide useful heating to reduce the carbon footprint of my 1885 rowhouse. I am now getting 8000-9000 BTU/hr out of about 100 ft of 1/2" pex buried 1 to 9 ft deep using a home made water-to-water heat pump made out of 2 small window ACs, 2 pumps and a Raspberry Pi computer controller. System cost about $3K.

My two storey, 14 ft wide house is about 1700 sq ft including a basement apartment. During renovations 15 years ago, I installed radiant floor heating using pex piping and a condensing natural gas boiler. Six years ago I added a 2-zone 18000 BTU/hr mini-split air source heat pump/AC with a 1 ton concealed ducted ceiling unit upstairs and a 7000 BTU wall unit in the basement. In heating mode, that off-loaded the boiler in warmer winter weather but my floors were cold unless I ran the boiler.

Since the house is attached on both sides, the heat loss is only about 18000 BTU/hr at the coldest expected temp of -18C. The gas boiler is fairly new and quite efficient, so I am not removing it, despite the fact that that makes me ineligible for government rebates. With the boiler and ASHP already working, I am not relying on the GSHP to keep from freezing. I can experiment without risk. I do not have to engineer for the worst case.

Using little digital thermometers bought on eBay, I recorded underground temperatures at 4 depths down to 5.5 ft over the 2021-2022 winter. Despite air temps down to -12C, even at a depth of only 14" the lowest temperature was 4.4C. That day the temp at 66" down was 7.5C. This convinced me that I did not need to go very deep to access warmth. My Toronto house is built on sedimentary glacial till where Lake Iroquois used to be in ancient times.

The backyard is only about 20x14 ft, not counting my paved laneway parking space. I am only using half the width (20x7) for the ground source piping. First I made a 9 ft deep hole by manually twisting a 2" PVC pipe (central vac duct pipe) into the ground. The pipe has teeth cut into its bottom end and I just twisted it down by hand and pulled up soil a few inches at a time. Using 1/2" copper street elbows I soldered together a copper spiral about 2 ft long with a 1/2" central copper return pipe. This "trombone" was inserted into the 9 ft hole with pex. Using a 3" trenching shovel I also buried about 56 ft of pex zigzagging around the yard about 1 ft deep (easy). In addition, I made a 5ft hole and packed it with 6 lengths of 1/2" pex. The two holes and the trench are connected to an inside manifold with 3 motorized valves to control the flow.

I don't have refrigeration skills, so I took the refrigeration loops out out of 2 window ACs (one old, one new) and carefully bent the copper refrigerant tubes (without breaking them, using bending tools) so that I could insert the hot "radiators" in one rectangular water vat and the cold radiators into another water vat. The system is not pressurized so that the refrigerant lines can exit the vats without needing seals. One pump (stainless steel), pumps a water/glycerin mix from the cold vat via the manifold/valves through the backyard loops and the other pump moves fluid from the hot vat to a plate heat exchanger into the pressurized floor plumbing. A bunch of cPVC piping and valves will allow floor cooling in the summer without needing the compressors. I didn't change the air conditioner wiring -- the fans are removed and the compressors and pumps just plug into computer-controlled outlets.

I had already built a Raspberry Pi computer-controlled pump controller for my heated floors that has 8 power relays and 24 temperature sensors to measure temps on every zone of the house, outside and the various pipes heating the floors. It uses little relay circuit boards from eBay (about $6 each), each with four 10 amp relays. I built another controller with 12 power relays and up to 28 temperature sensors for the GSHP. Using thermistors (100 for $6 on amazon) taped tightly to the pipes and covered with insulation, I can monitor and measure how the system is working and see the underground temperatures in the backyard. Python programs have full access to all sensors and can control the compressors, pumps and valves from software. I'm still working on the software.

The system has been in operation since Oct 2022 and I continue to tweak it. The winter in Toronto has been warm and I have only had to use the gas boiler for 3 cold spells so far. The ASHP plus new GSHP can keep the house warm (22C or better) down to an average daily outside temp of -5C. Electricity usage is up and gas usage is way down. Currently it is 0C outside with 2ft snow cover, and I am pumping -12C water/glycerin out into the yard and getting it back about 2C. The compressors bring the temp up to about 27C which runs through the floors constantly. Power consumption is about 965W using a single 110V 15A circuit. I estimate a COP of about 2.7. My conclusion is that shallow ground piping can provide significant auxiliary heat and a cheap, home-made heat pump can access it.

03:21 UTC


More about geothermal cooling

Hello everyone, I'm completely new to geothermal cooling system yes I know how it works, but do anyone of you using this technology in your building and if you seen it please share how effective it is, also what are the cons pros you found in this technique

04:50 UTC


Reservoir engineer interview tips anyone?

Hello guys. I will have an upcoming interview for the reservoir engineer position. I'm from the petroleum industry (petroleum engineer) and haven't practiced my profession for a long time. I have no background in Reservoir engineering, but a master's in Geology. The management informs me to bring scientific calculator since there will be an exam. Any tips on what should I review?

23:13 UTC


Can an electrical panel upgrade needed for geothermal get the US tax credit?

I'll need to upgrade my panel and run lines before the geothermal gets installed. I'm hoping I can roll that expense into my Residential Clean Energy Credit for the geothermal. Anyone have any experience with this?

15:49 UTC


Waterfurnace thermostat manuals?

Does anyone know where I can find the details of the waterfurnace thermostats? I found the information on their "literature" page, but I'm really looking for information on the wiring they have.


23:15 UTC


Anybody here from Central NY have a Geothermal system?

Recent returnee to the Empire State and Central NY (and new to this subreddit). I was talking to an HVAC tech today about possibly putting in a mini split system as a primary heat, with my radiant floor system being a secondary. He was suggesting possibly putting in a Geothermal system (I've got plenty of land) and tie it into my existing radiant heating system (possibly tying in the hot water as well). The reason I want to add a mini-split, is the radiant heating system doesn't do an adequate job of heating the whole house. It currently runs on propane, and I want to move away from fossil fuels to to heat, cook, and dry my clothes.

I'm wondering if:

A) anyone on here is from Central NY (I see posts from the Buffalo area, which is Western NY)

B) any recommendations on who to get quotes from and who to stay away from.

The HVAC person who came out today is from a large company that covers Rochester, Ithaca, and Syracuse. I did find another company out of East Syracuse and will probably get a quote from them as well.

I have a lot of other questions about putting in Geothermal, but I'll lurk around a bit before I post those questions.

Thanks in advance.

23:38 UTC


**Geothermal Heat Pump Quote and Informational Survey** A Community Resource where ground-source heat pump owners can share quotes, sizing, and experiences with the installation and performance of their units. Please fill out if you're a current or past geothermal heat pump owner!

Link to the survey

Link to the responses

Hi all!

Let's be honest. HVACing can be stressful as a homeowner, and this can be especially true when getting geothermal installation quotes, where the limited number of installers can make it difficult to get multiple opinions and prices.

Inspired by r/heatpumps, I have created a short, public, anonymous survey where current geothermal heat pump owners can enter in information about quotes, installations, and general performance of their units. All of this data is sent directly to a spreadsheet, where both potential shoppers and current geothermal owners are then able to see and compare quotes, sizing, and satisfaction of their installations across various geographical regions!

Now here's the catch: This spreadsheet only works if the data exists. It's up to current owners, satisfied or otherwise, to fill out the survey and help inform the community about their experience. The r/heatpumps spreadsheet is a plethora of information, where quotes can be broken down in time and space thanks to the substantially larger install base. With the smaller number of geothermal installs, getting a sample size that's actually helpful for others is going to require a lot of participation. So please, if you have a couple minutes, fill out what you can in the geothermal heat pump survey, send it to other geothermal owners you know that may also be interested in helping out, and let's create something cool and useful!

Link to the survey

Link to the responses

22:08 UTC


Given that a geothermal loop supposedly should last 50-100 years does anyone know if home insurance could help with issues down the road? Thanks.

21:41 UTC


Princeton Air Experience?

Planning on reaching out to Princeton Air to ask about a NG conversion, but wanted to check what anyone’s experiences were here (if any) in Central NJ.

18:27 UTC


Articles about the basics of geothermal energy

I work for a company in the geothermal industry and I started writing these articles about geothermal energy and thought a few people on this sub might benefit from them and or possibly start a good conversation about the topic. As I am researching and writing I find myself asking more and more questions and debunking some common fears. Geothermal Article 1 Dip Into It.

06:03 UTC


Gauging interest in Quote Comparison Form for existing GSHP owners

EDIT: Survey is now live

Hi all!

If any of you have lurked on r/heatpumps, you've seen pinned to the top of their page a survey form for existing heat pump owners about their installations, with the output publicly available. This is a great tool, and while every house and situation is unique, it can still provide some basic information on the current market for anyone interested in getting quotes.

On that note, I was wondering if there would be interest in setting up something similar for this subreddit as well, as I see no reason such information wouldn't be helpful for our heat pump community. I can set up the survey form rather easily (I've already made a prototype form, no don't fill it out yet!), and should there be enough responses and interest in the initial get-go, we could try and have it pinned at the top of this subreddit as well! Maybe...

Anyways, before I attempt such a daring feat, it'd be good to have the right questions on the form. Currently I have (all optional):

-What type of geothermal system did you have installed? (Forced Air, water-to-water, other)-Brand/Unit of Heat Pump-How many tons (if multiple units, include both separately)-Loopfield Orientation-Additional Loopfield Information-Total Cost (before incentives)-Total Cost (after incentives)-Extras (ex: Water heater, Ductwork)-Country-State/Province-City/Town-Size of Heated Space (sqft)-Company Used To Install System-Date of Receiving a Quote (Approximate)-Number of Months from Signature to Installation of System-Are you satisfied with your purchase? -Additional Comments (i.e. why you're not satisfied, things you want to tell others, favorite color)

Anything crucial missed? I tried not to make it too long, as longer form = lower response rate. If people on this subreddit think there'd be genuine interest in having such a tool, I'd be happy to make a formal post tomorrow with the form and resulting output available and go from there. Even if it's not pinnable, reposting it once every few months is still an option. But if it's going to result in 3 submissions, one of which is my parents filling it out of pity, I could probably skip the humiliation and find some other mundane topic to fill my data-collection obsession instead.

22:59 UTC


Absolutely poor heat pump performance

Hoping to get some help and insight on absolutely poor heat pump performance that we are getting with a 4 ton Bosch split unit.

Background: We got two (4 and 3 ton) closed loop ground source heat pumps installed back in July 2022 in southern NH.

4 ton unit is connected to a 600’ (two 300’ manifolded) vertical loop with 1.25” pipe. 3 ton unit is connected to one 450’ vertical loop

Both units worked flawlessly in the summer but come winter the 4 ton unit (service first floor) has been absolutely miserable. The system runs 24*7 as soon as the temp falls below freezing avergaring at about 2.8 kW and using roughly 50-60 kWh in 24 hours and still could not keep up with the setpoint of 68 degrees F. The system is designed for 70 degrees F indoor temp and -3 degrees F outdoor.

I called the service tech end of Dec 2022 and they said its a faulty TXV and unplugged my heat pump forcing me to use backup propane furnace.

1.5 months later they finally replaced the TXV on a day when the outdoor temp was in the high 50s F. The system worked and everything seemed fine.

Two days later temp drops to below freezeing and behold the same problem exisits. At this point I am not sure what is exactly going on, so any help will be appreciated.

Some additional info:

  1. Location - southern NH
  2. House size - 3400 sq ft
  3. Insulation - decent, not completely sealed but got a lot of work done on air sealing and adding more insulation.
  4. Manual J - Unsure, but design heating load for 4 ton was 35000 btu/hr and 3 ton unit was 28000 btu/hr
  5. EWT - 43 F
  6. LWT - 37.9 F
  7. Outdoor Temp - 22 F
  8. Flow - 12 gpm (Water plus antifreeze)
  9. Return air temp (measured near the filter) - 65 F
  10. Supply air temp (measure at the unit) - 91 F
  11. Temp of vapour line (thick insulated lineset going from heat pump to A coil) - 95.4F

Any help/guidance would be much appreciated as right now we are back to using propane furnace since its much cheaper to operate.

15:36 UTC


Desuperheater tank maintenance?

I just flushed the sediment and checked the anode rod on my hot water tank, was wondering if I need to do the same for my desuperheater tank. Anything else I should be doing? What are you all doing for maintenance if anything?

13:50 UTC


Bryant or Waterfurnace? Hard choice between two quotes..

Eyeing our options now that all the quotes have come in and (personally) I'm leaning towards one of the two geothermal options we've received. A few of the ASHP are close backups, but the two Geos are just too tempting in my mind. The problem is I'm not entirely sure which would be 'worth it' in the long run. For a system that will (hopefully) last for 20-30 years.

System #1. Waterfurnace 7 series, 3 ton, full ductwork installed with hot water (preheat & working tanks). Well drilling included (450' / 150' per ton).

System #2. Bryant Evolution GZ, 4 ton, full ductwork installed with hot water (preheat & working tanks). Well drilling included (800' / 200' per ton).

Price difference between the two is approximately $10,400 (Bryant is higher), pre-tax refund at least ($7,200 after federal refund). Is the additional tonnage from the Bryant (and bigger loop field; vertical wells for both) worth the increase? How do the Bryant systems compare to Waterfurnace in terms of energy efficiency, comfort, etc? From the service perspective, it looks like both companies have a long history, though the Bryant dealer has more online reviews than the other, but nothing negative for either of them found.

Is brand more important here or the system size (tons & well field)? I've seen a lot of information on Waterfurnace lately, but not much on Bryant, so just not sure how they compare or which would be best advised in this case.

13:37 UTC



I recently got a ballpark estimate from an installer for 60k (actual quote coming next week). This looks to be in line with others I have seen on this sub. However, if you google geothermal system price, it generally shows a range of 15k-30k. Does anyone know why there is a huge difference? Do these websites assume a new construction which is more energy efficient? Are these just way out of date and the pandemic or something caused prices to go up that much? Is this quote just way too high?

I am working on setting up at least 2 more quotes if I can, but there are not a lot of people in my area that do geothermal.

2600 sqft old (1901) leaky house in northern PA. He mentioned something about needed to update duct work because 6” we have probably wouldn’t be enough. I didn’t really understand that since the duct work is enough for the current furnace but I’ll probably ask that as a separate question here later. It would be a horizontal install.

Edit: Estimate was for 2 water furnace units. Not sure of the model it will be in the actually quote next week. I would guess two 5 series.

15:26 UTC


Well Distance (from each other)?

Just looking to scan on anything official anyone knows about on how far apart wells should be from each other. I'd heard 20' but as we get closer to an install date I realize I'm unclear on the calculations on the radius a well draws thermal energy from. We're planning on a 2x425' closed loop.

20:16 UTC

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