r/geothermal

Hey Everyone,

Longtime lurker to reddit and brand new to geothermal. AI / google cannot answer my questions so I made this account just for this question. Yeah I'm an actual human, I'm pretty handy, reasonably smart, but I need advice without 'industry terms' because I am BRAND NEW to geothermal.

OK here goes.

I am going to build a 24'x 36' free standing detached garage in Connecticut. 100 amp service that will have a sub-panel in the garage (house has 200 amp). Slab on grade, Versatube prefab steel structure with insulation and drywall. The garage will be used for working on cars and such. It will NOT be a man-cave.

All I want is a floor that won't freeze my feet and body as I work in there over the winters. So my thoughts are to run pex radiant in the slab to get the concrete slightly warmer. I am NOT interested in a "heated garage" I just don't want to be miserable when I am laying on the floor for hours on end. I am pretty aware of how to insulate and pour the slab, and reasonably confident in the pex layout. The information I am looking for is how to heat the liquid in pex using ground warmth only. I would like to avoid heating the liquid with a furnace of any kind. I.E. "free heat"

I imagine a simple pump that will constantly circulate the liquid and keep the concrete "warm". To paint the picture a bit clearer, I plan on working in there with a jacket and hat on and I really don't mind the cold that much. So again, it doesn't need to be a living space, but I also don't want an ice rink. As the snow falls off the car, I'd like it to melt and run down the pitch.

Please explain it like I am 5, I'm pretty sure have an undiagnosed learning disability.

Thanks in advance

Peace, love, and all that happy horse poop.

edit - ceilings will be 16' high or so. I have buddies that owe me favors so site work and concrete work will be done on the cheap. I am an electrician so hanging a couple of space heaters from the ceiling would not be hard.

All I need really is for snow to melt when it falls off the cars and my toes not to freeze inside my boots.

Will be a new build. Looking at geothermal vs traditional.

Running horizontal lines is no issue, I just installed my 1100ft waterline at 4ft bury. I've heard 95% of the cost is in the ground but since I'll run all of these myself. What makes more sense in efficiency and roi?

I'm looking at installing a geothermal vertical loop system on my acreage in the Buffalo/Western NY area. My installer has been very responsive in answering questions verbally or on email. However, I really don't feel like I have a good understanding of the ground loop design. As it is not something I can change on a whim...that concerns me.

My property is on a former quarry. The installer is local and proposed a horizontal loop and we signed on that. We were digging on our property for another project and we encountered bedrock within 2-4 feet. Subsequently, we pushed the geothermal contractor for testing, and they confirmed all their proposed locations are too shallow for horizontal

Now, I'm concerned. As I had to push for testing, the installer did not propose it. Tho, fair enough, it was mentioned in the contract. Technically, up to me to push for it.

Now, we are looking at vertical loops. However, I'm not getting many details beyond the depth and we can put the loops "any where you want." This last is what gives me pause. It just seems a bit unscientific and leaves me feeling uninformed.

Has anyone gotten a design or loop report prior to purchase?

https://gdr.openei.org/files/1594/500ft%20260%20holes%20GLD%20Report%20%281%29.pdf

https://igshpa.org/wp-content/uploads/CSA_Residential_GHX_DesignSummary.pdf

I'm particularly interested in hearing about installation testing (see below from a mockup). And of course, I'm concerned I am being to anal about wanting this. This contractor has a great local rep.

Mockup of Loop Design Report

I've had geothermal heating and cooling for a year now (near Ottawa, Ontario). Reviewing the electricity bills for this period shows very high consumption during the winter months. In January, for example, we used over 2,200 kWh. While obviously not all of it is due to heating, the difference to summer months (about 900kWh) cannot be explained by any other change in consumption. My wife and I opted for geothermal under the assumption that it is the most economical and environmentally-friendly heating option, but now I'm not sure about the former (the latter is still plausible in Ontario, as the vast majority of electrical production is clean). Even the summer consumption is not that much better when compared with the A/C unit we had in the previous house.

Is this the norm, or is there perhaps something wrong with this specific unit?

Does any one know how much linear ft/meters of pipe(tubing) needed to be buried to run certain sizes of air cooling units? Example: I need 1000 ft of 3/4 poly to cool a 1000 sq ft house etc. why does no one talks about insulating the up pipe to the house etc. shouldn’t all the pipe above the main coil be insulated. Another question… wouldn’t laying the pipe parallel be more efficient than coils under ground? I’ll have more questions after I hear these responses.

On a recent trip to the southwestern US, I found that most residential homeowners had never heard of geothermal before. Is there something about desert climates that makes geothermal less optimal? Or is it just that people haven’t adopted yet?

We are house shopping and scheduled to look at a house tomorrow that has this system. Of course I would have a pro inspection done before an offer but Reddit never lets me down!

This house was built in 1995, I've not gotten an owner's disclosure yet but no mention of the system being replaced so I'm assuming it's 30 yrs old. I've read that expected lifespan on these things is 20-25 yrs old, so is it in it's last years? What do I look for and what questions do I ask.

Does anybody have any advice?

Hi Everyone,

I have a Water Furnace 3-zone geothermal system I installed in 2012. It's worked great for the past 14 years. Yesterday, during annual preventive maintenance, the repair guy said that the Dual Pump Flow Center is drawing too many amps and needs replacement, and when they do that, they'll need to do a Geothermal loop field water exchange; I was not seeing any problems but he said that the Flow Center is overheating and if they don't replace it then it could destroy the entire system at any time. If this happens I'll have to replace the entire system at a cost of over $30K, so he recommends I replace the flow center for just over $5K. Does anyone know if it sounds like I'm getting good advice or more like I'm being ripped off? Just looking for some advice from experienced users and/or maintainers. Thanks much for any help you can provide.

Forgive my poor terminology. Very new to geothermal.

Cooling quit working a week ago. Since then, 3 techs have been out and replaced 3 electrical parts, none of them addressing the root cause. As of today, they think the issue is the whatever little black piece triggers the compressor to enter “second stage.” It was tripping a fuse and literally burnt up the brand new board they were installing. At this point, I think I’m just going to replace the entire thing given it’s age.

However, my concern is whether there could be something in the underground heat loop that caused issues with the interior system. My only reason for concern is that I had a patio installed over part of the exterior system (probably stupid, I know). However, that was installed a year ago and I’ve had no issues until now. it just bothers me that their description of the root cause isn’t very clear to me.

Again, I don’t mind replacing the system. Just want to make sure I’m not going to have the same issue again if something in the loop is messed up. I’m assuming they have a way to test the loop separately to make sure that’s not a factor?

Thanks for any insight. I’ll ask them more tomorrow when they come to quote a replacement.