/r/geothermal

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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/r/geothermal

4,827 Subscribers

2

Geo cooling without a compressor or heat pump?

So I have a friend who has been asked to build 10 non-permanent student houses. He has come up with a cheap solution and is not planning to earn anything on the project, other than the time he spends building.

So far so good.

The units will be 25 square meters or 269 square foot big.

But during the summer, the temperature is about 30C or 86F, so the small rooms will be fairly hot very fast. Winter is very mild in the area.

As the area is very big - 10.000 square meters or 107.639 square foot - I was thinking:
By digging 5 meters (196 inches) below ground, you could create a loop, whereby by forcing air through a pipe, the air would cool.

I have done this in my greenhouse, and it cools during summer and heats during winter ( along with the sun ).

As he is trying to help out, the project needs to be as cost-efficient as possible, and I am trying to see if I can give him an easy and co2-friendly way to address this issue.
Adding heat pumps to each free-standing student house would probably kill the budget.

If it worked in my greenhouse, should it not also work in a well-isolated house?

I know the ground temperature at 54 cm (21 inches) below ground, right now is 11C/51F, while the air temperature today was 18C/64f.

If a room can be cooled to 22C/71F or 24C/75F during summer, that would be quite ok.

Perhaps I'm just waaaaaaay to simple-minded to understand thermal dynamics? :)

3 Comments
2024/03/28
16:20 UTC

3

Horizonal loop sanity check

Hello. I'm currently self building an ICF house in rural east Texas and would like some feedback on a geothermal system I'm speccing out using a horizontal loop. I figured it best to paint a picture with all the relevant details. The system makes sense to me, but it's best to verify with experience.

Land info: I'm on a large acreage lot with a clear flat home site, with the proposed horizontal loop location about 150ft from any trees. I have an excavator and can get the loop about 9ft deep, which is about 6ft into the clay layer and free of any rock or other contaminants. That depth won't hit the water table.

House info: 2200sqft main floor with a 2200sqft basement. Both levels will have exterior ICF walls with a 6" concrete core. The attic will be vented, but there will be R50 blow in under a zip system attic floor deck; I'm considering the attic an exterior space with only a couple plumbing vents and ERV pipes penetrating the house envelope on their way to the attic wall where they'll terminate. I'm not going to run a blower door test, but I imagine it'll come close to passive house standards if I really focus on the window and door sealing details. The geothermal unit will be located in the conditioned basement with all the duct work running below the main floor joists and feeding into floor vents.

With those details in mind, it feels like a 4 ton system would be more than sufficient. I'm not sold on any particular brand, though I've been looking at this unit, utilizing this set of loops. This will be a DIY install and I live far enough out that the county doesn't give permits for anything. I'm at a point in the build where pivoting to an air system isn't an issue, but aside from the standard geothermal benefits, I like the idea of not having outside AC condensers.

So yea or nay on a horizontal loop given the situation?

Thanks!

7 Comments
2024/03/28
05:14 UTC

3

How much can i expect to pay for a geothermal heat pump?

2400 square foot house ductwork Vertical drilling High efficiency unit

27 Comments
2024/03/21
19:11 UTC

5

can you use a geothermal heat pump to heat hot water and heat the house with ductwork?

sry if i sound as an idiot but will you need to have a separate hot water heater or can you just connect it with the geothermal pump?

the house is heated and cooled with ductwork blowing the air.

10 Comments
2024/03/21
18:49 UTC

1

Hourly pattern for electricity consumption with geothermal?

Does anyone have information on typical patterns for hourly electricity consumption for geothermal operation? We're in climate zone 6a (very heating dominant) and I expect there to be a seasonal impact on these demand patterns.

Context: We're in the final phases of commiting to a GSHP system (replacing aging AC and propane HVAC), and currently have a time of use (TOU) plan with our electricity utility that we leverage to cost-effectively run appliances and charge our EV. Seeking to learn more and consider if we need to change our plan with the electricity provider as our daytime consumption is more expensive than our super off-peak consumption (11 PM to 6 AM). Interesting opportunity/complication: I can change my plan, yet only every 6 months - which might play into seasonal patterns if that applies.

Appreciate all your insights - its been super helpful learning through your posts and conversations!

3 Comments
2024/03/21
17:27 UTC

3

Geothermal heat pump or air source heat pump for DFW?

Looking for the most efficient way to get all electric home. Which is most efficient for heating in the winter and Cooling in the summer?

25 Comments
2024/03/20
14:57 UTC

5

Good book to learn to install a geothermal system

I have read through "Modern Hydronic Heating: For Residential and Light Commercial Buildings" and have done my boiler install with a fan coil and radiant floor. I would like to put in a ground source heat pump and ground loop. I will be filling in a swamp and want to bury the tubing as i put in fill so I would like a book that covers how to create a ground loop and how to actually tie the heat pump into my system. I want to do space heating, snow melt, DHW, and the hot tub in winter. I want to do space cooling, DHW, and the hot tub in summer also. So I would imagine I will need some complex valving, heat exchangers, and buffer tanks. What is a good book or series of books on this?

1 Comment
2024/03/18
17:51 UTC

2

Trane TVGX

Does anyone have a Trane TVGX or has considered it? I am eventually going to plan for the replacement of our 4-ton Climatemaster Tranquility 27-ton system, which is now going on 13 years. It has literally since it was put in leak refrigerant. They attempted to find the leaks numerous times and fixed them, but it loses about 1 lb every year.

1 Comment
2024/03/18
17:20 UTC

3

Permits

Do I need a permit to install geothermal at my house? I’m in RI.

5 Comments
2024/03/16
23:00 UTC

5

Vertical vs. horizontal loop costs and contractors

I received a quote for installation including a vertical loop. i know that the horizontal loops cost less and asked the contractor about it. He said that their subcontractor only drills the verticals and I'm welcome to find someone else to do the horizontal. He said that the loop cost portion was $25.5k. How much could I save with the horizontal and how can I find a contractor? Google is no help- it only gives me HVAC companies. Probably need to search som other keywords.

21 Comments
2024/03/16
22:20 UTC

1

Geothermal water tank flush

Bought a house last year that has a unit installed with a water tank and I was wondering if it needed flushed like a regular hot water tank?

3 Comments
2024/03/15
15:28 UTC

3

Waterfurnace 5 series or 7 series?

Hi all,

We are currently remodeling our house and looking to install geothermal, our previous house had it and we really miss how much quieter it is than the relatively new ashp that was installed in the house we purchased. There are only a handful of geothermal installers in our area and the Waterfurnace dealer by far seems the most competent and capable. So we know we will be going with Waterfurnace, we just aren’t sure which option to pick.

It is $5,164 more to step up from a 5 to a 7, so after the tax credit that makes the total investment just over$3,600 more. The 7 would have the symphony thermostat system. We are doing a full remodel and the house should end up being very tight and well insulated. I am thinking that the 7 may be worthwhile as we likely won’t need the full capacity of the unit for most of our cooling and heating loads, but that is just a gut instinct.

Does anyone have numbers on how much more efficient the 7 is over the 5 or any other compelling reasons to get the 7? Pros and cons to the symphony thermostat? I’m used to using ecobee and have it set up to be controlled through Apple’s home app - can the symphony be controlled through Apple home as well?

21 Comments
2024/03/14
05:12 UTC

3

Complete newbie need help exploring geothermal vs. air-source in 1800s Brooklyn brownstone

As the title suggests - I know truly nothing about geothermal or heating/cooling in general so apologies in advance if I am not providing sufficient info/things don't make sense!

My family owns a 3-story brownstone in Brooklyn (probably ~4000 SQFT). It's a multi family unit (3 units) that we rent out and we are renovating the bottom two floors and are considering updating the heating/cooling for the entire building since we are doing this renovation anyway and there are some attractive incentive programs available. The building was built in the late 1800s and uses a boiler fueled by natural gas and the radiators are super old-fashioned hot water radiators (not steam). There is currently no AC (tenants use window units) and I don't believe we have ducts but could be wrong. Overall, I know that the building is probably not very energy efficient so any update to what we have will likely be a significant savings.

I have been doing some initial research and found that there is up to a $45k rebate on geothermal installation since our house is in an economically disadvantaged zone (LINK). Is this the sort of thing that can be installed in a brownstone? We do have a backyard but I'm super unclear on how much space is typically needed for something like this. Can it just be dug under the building? I'm trying to weigh geothermal against an air-source heat pump, which provides a $12k incentive (LINK).

I've also included the feasibility assessment I pulled for our address from a NYGOV site below. Are there any significant advantages to one over the other? Is air-source easier to install, particularly considering we are in a brownstone? Are permits harder to get for geothermal in NYC? Does the size of our home mean that geothermal will be significantly more efficient than air-source? Any thoughts/input would be GREATLY appreciated! I just want to have bit more objective knowledge going into the assessment and quote process because I anticipate some degree of selling/bias from these contractors. Thank you so much in advance!!

https://preview.redd.it/iaxw51o6r1oc1.png?width=927&format=png&auto=webp&s=8654a1102aa8a090dcfe27d0bfffd3861e8adfdb

19 Comments
2024/03/13
06:06 UTC

2

Horizontal loop effectiveness in Arizona

Question for those who might know. I’m building a house in the Verde Valley of Arizona. I like the idea of geothermal and it is only affordable to me because I can dig the trenches myself and lay the lines in the horizontal fashion. I could go deep and have plenty of room for long runs. However I have yet to get a warm and fuzzy from anyone that the soil here will work well in that capacity. The soil is basically decomposed granite, sandy, with loose rocks. Digs easy enough.

My load calcs spec a 3 ton unit and right now Im planning a carrier infinity 24 air to air unit (unless geo seems viable).

Does anyone have direct knowledge of horizontal ground loops in this area? Know of a test (that’s reasonable) to measure the soils effectiveness for this application?

Thanks

4 Comments
2024/03/13
01:45 UTC

0 Comments
2024/03/13
00:42 UTC

1

Thinking of going water furnace, in canada, can anyone give me rough pricing?

Hello, thanks for reading

I'm planning to do geothermal waterfurnace upgrade in the future.

This work will be 95% diy, if not all of it. Seems everything required I'm more than capable of.

I'm trying to estimate costs, and i can't find any pricing online for the water furnaces. I dont need exact quotes, just looking to get an idea.

Have 1500sq ft home with matching basement. In a very cold winter climate, very hot summer. Can see -30c and +35c manitoba canada.

I believe I need a 3 ton unit.

Could anyone post some costs for the units?

Thank you.

13 Comments
2024/03/12
18:21 UTC

2

New install question? (Make Waterfurnace)

How bad of an idea is it to put the unit outside? (Cold climate snow and all). Obviously it's an add-on install split system.

I'm at the purchasing stage and I just saw that there is outside units, make my install much easier and the noise would be inexistant.... Original plan was to put it inside but just saw that they have outside unit.

Waterfurnace Series 5

7 Comments
2024/03/12
01:28 UTC

4

GeoCool 5 Ton Inverter Series Review

I had an earlier post (https://www.reddit.com/r/geothermal/comments/1afz8zu/geocool_inverter_series_installation/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button) where I shared some of the trials and tribulations I had installing the GeoCool 5 ton inverter series system. In this post, I will share additional details on my (unfortunately, very negative) experience.

Background: Purchased the system from Ingram's in January. Ingram's website describes this as a DIY system, but the MrCool warranty says the system must be installed by a "professional". They need to figure out which it is. I would describe myself as advanced DIY. I have my EPA 608 certification and the majority of tools necessary for working on a geothermal system, including refrigerant recovery. I have a doctorate in Organic Chemistry and have a very solid understanding of thermodynamics and heat transfer. I was a mechanic in the Air Force and I have always done my own electrical and plumbing on every home I've owned. I have maintained and even rebuilt (new compressor and refrigerant/water heat exchanger) on my old FHP geothermal system. I have a background in programming PLCs connected to multiple sensors (temperature, pressure, etc.) Enough about me.

I installed the system and never saw the compressor ramp up to give more than 33,000 BTUH heat extraction from the groundwater (open loop, water temp 55 F). AHRI certification lists 55,000 BTUH as the max heat output. I don't have the equipment to measure duct air velocity, but I can tell that it is much lower than the previous air handler I had. The data plate on the blower unit of the new system rates it at 1400 CFM with an ESP of 0.5 WC. This seems low to me for a 5 ton system. The A-coil circuit board has a DIP switch for setting the blower speeds. There are five manual settings. Changing it did not effect the blower speed from what I could tell, and by measuring the sound with a decibel meter.

I contacted MrCool and opened a service ticket. They do not answer their phone. After ten minutes you have to leave a message and (hopefully) someone will get back to you. They created a ticket for me and I was contacted via email. I was asked to perform a lot of tests and measurements, which I did and forwarded the requested information to them. I also asked a lot of questions, which mostly wen unanswered. Typical time between sending an email and getting a response was 2-3 days, but the longest period was 10 days. I eventually requested a new A-coil circuit board (which controls the fan speed) under warranty. I was ghosted. I filed a BBB complaint and received a new board within a couple of days. I replaced the board but the problem was not resolved. At that point, MrCool support told me that the system was operating within normal parameters and that they could no longer help me. Total time with all the communication delays was almost two months. I asked to return the system for a refund and was told that I would have to go through Ingram's for that.

I sent a message to Ingram's a few days ago via their online messaging system asking about a return and refund, but have not yet heard back from them. Their website states that you can only return a system for a refund within 30 days, so I don't expect a positive response from them. Ironically, the BBB lists Jason Ingram as the owner of both Ingram's Water and Air, and MrCool. Ingram's has a 30 day return policy, but MrCool drags their feet with the tech support. You can see where I am going with this.

I was told that this was a new system and that MrCool has only been selling it for two months, so I must have been one of the very first people to buy it. I'd love to hear if anyone else has had any experience with it. My feeling is that there is a design flaw in the logic that controls the ramping up of the fan speed and the compressor speed, but I will never know because MrCool will not share information with me.

Bottom line: I spent over $6,000 on a 5 ton system that is giving me a little under 3 tons of heat. I wish that I had read all the BBB online reviews of Ingram's and MrCool prior to purchasing this system. I can not recommend anyone buying this system.

21 Comments
2024/03/11
19:11 UTC

1

New series 5 WF tripping 40A breaker

Just replaced a 20 year old premier WF that ran almost flawlessly. Decided to upgrade to series 5. Unit was installed and when the tech turned the system on it tripped the 40A breaker. The old premier unit has never tripped that breaker. The system starts up but when the compressor starts it trips. The tech checked the compressor said it was fine. Said it was a weak breaker and will come back the next day to replace. I’ve heard of weak breakers that have trip/operated several times but the only thing I can think of is the breaker is 20 years old so I don’t think it’s that. Any ideas from you more professional guys would be greatly appreciated.

6 Comments
2024/03/11
15:04 UTC

3

Hydron Revolution Geothermal Issue [UPDATE: Blown compressor + more]

I just wanted to update everyone on my situation with my Hydron Revolution Geothermal system. Previously I mentioned that I lost water pressure (due to a worn out contact switch it turns out), and it was causing a LP fault on our system... as there would be no water flowing through the unit.

Well, the other day... I noticed the same issue... it was blowing out cold air... however this time we had already replaced the switch that was bad that controls our well (we run on an open loop system). I also wanted to mentioned there was no LP fault led, or any fault leds at all... which I thought was strange.

I reset the breaker, then turned the unit back on, and it was still blowing cold air.. except there were no fault light LEDs still.

As I walked back upstairs, I noticed the lights flickering in the kitchen, then heard an actual explosion from the basement... as I rushed down there expecting to see one of our pressure tanks ruptured... I saw the panel blown off the side of the geothermal system... as well as an electrical smell & smoke as well.

I turned of the power & water... and waited for the heating and cooling company to come out.

Fast forward... a pin was blown out of the compressor... and the compressor was bad. Luckily it was under warranty and the part was free to replace, but all the refrigerant was also gone... and that's not covered nor is the labor to replace it.

I had the new compressor / refrigerant installed, but it was still not working... and the heating and cooling company I was using, then informed me they believed the heating/cooling coil was plugged up as no water would flow through it.

I do have a lot of high mineral concentration where I live...so it's definitely possible... but they also told me this would not be covered by warranty because I should have been maintaining it?

They want me to purchase a new coil.. which they said is around $1000... and I can't purchase it myself, it has to go through a licensed contractor supposedly (Hydron confirmed this when I called them).

My question is... should I be flushing my unit yearly? Or should I install a filter for my geo thermal system that I can clean myself?

Also, am I being ripped off here? Can I order the part myself some how? They told me it's an all day job to replace the coil because they have to drain the refrigerant again when they replace the coil etc... they want over $1000 in labor (plus I have to buy the part conveniently through them for $1000).

I asked if we can simply flush the coil, or try to, but they said probably not because if it's plugged up as much as it is now, it probably won't work... and you can't use a wire of any sort (supposedly) because you could scratch the inside of the coil causing it to work less efficiently.

I'm sorry for the long post... but if anyone has some advice... I'd greatly appreciate it.

Thanks in advance!

7 Comments
2024/03/10
22:30 UTC

7

Geothermal Pricing in Upstate NY

Looking to see if anyone else in NY or the north-eastern states have gotten Geothermal quotes within the past year.

I recently received a Geothermal Horizontal system priced for a 2,000 sq foot house in NY (Ranch).

Waterfurnace 7 series (5 ton): $14,500

Supplemental Geo hot water: $3,500

Thermostat, loop, plumbing, and labor: $28,000

Total: $46,000

Waterfurnace Utility Rebate: - $7,500

Hot water rebate: -$100

Contract price: $38,400

30% Fed tax credit: $10,800

NYS Tax credit: $5,000

Total Investment: $22,600

Thoughts??

22 Comments
2024/03/09
02:18 UTC

4

I am a dummy, quick question, hopefully this is the right place….

2 years ago, we drilled a well and failed to hit water. A few people have asked me if I could still use it somehow, like for geothermal… I have no clue how geothermal works or what types of systems are out there…

This well has a depth of 583 feet and had managed to fill up with water to about the 200 feet below ground level. It’s 8 inches in diameter ….. I lowered a thermometer down to water level and got a reading of 18 degrees celcious.( it’s possible it could be warmer lower down) (It is winter in Canada so it was steaming a bit out the top of the collar).

Can I do anything with this? Or is it still just a $40,000 cool hole in the ground haha.

17 Comments
2024/03/07
23:25 UTC

2

Frequent filling of closed loop system

I have a Waterfurnace Series 7 on a closed loop system. The system is about 5 years old.

I topped up the water in the system in October and just got a freeze alert today and topped it up again. Is this normal? I was told this could happen for the first few years but should settle out.

Secondary question - when I add the water, is there a way to purge the air out of the system or does it do that automatically?

If this is not normal, is going to a non-pressurized system a better solution?

My installer sold his business and I don't have a lot of faith in the new owner so I'm asking here first.

4 Comments
2024/03/07
18:00 UTC

8

Electric Bills Through the Roof

I realize this is difficult to tell without knowing all the specifics of the system installed, but I recently had a Dandelion Geothermal setup completed and my electric bills basically tripled in the months of December & January.

They sent some Post Install documentation over that said it wouldn't be unusual for your usage to be four times greater than it was in the same month the previous year, but it seems like our overall energy consumption is much higher than a lot of others that have posted here.

We used 3400 kWh in December and 3108.00 kWh in January compared with 1200 kWh and 800 kWh in the same period the previous years. We basically keep everything set to 69 or 70 degrees on all of our thermostats.

Does that seem normal?

Thanks,

57 Comments
2024/03/07
17:57 UTC

3

Has Dandelion always charged service fees when something malfunctions in the first year?

I continue to be deeply frustrated by Dandelion. 5-ton heat pump installed last May and we’ve faced countless issues, the least of which were leaks and the worst resulted in 9k in ductwork modifications to move air to our upper floor. Old heating system worked great, but we wanted to stop burning oil and we’re assured this would be “maintenance free” and would pay for itself in ~10 years.

We’re currently needing to reset the system at the breaker to get it to turn on and off (maybe an issue with heat pump communicating with thermostats?), and they have the gall to charge us $300 for a service visit. This is the first service visit of MANY that has incurred a charge and I’m wondering if this is a new policy.

3 Comments
2024/03/07
15:44 UTC

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