Geo thermal

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Midalake

Member
Aug 22, 2010
40
UP of MI
There does not seem to be too much talk about geo here. So I am building new and my only main heat source options are Propane and Geo. Thus I need to give Geo a Very hard look. The only way it can be installed is closed loop in a lake. Can anyone tell me what is working for them? Any other sites to go to for go info? What are good brands to go with? This whole mechanical thing for the house is a little overwhelming.

Dave
 
Bit off topic, but have you researched passive solar with geothermal backup? If I were building a new house it would certainly be oriented around passive solar.
 
My system is closed loop in the ground. I have a 4 ton Climate Master Tranquility 2 stage. I really like the geothermal. No outside units everything in house. Great for cooling in the summer and the heat in the winter. You probably know about the tax credit for geothermal. RESIDENTIAL RENEWABLE ENERGY TAX CREDITS
Consumers who install solar energy systems (including solar water heating and solar electric systems), small wind systems, geothermal heat pumps, and residential fuel cell and microturbine systems can receive a 30% tax credit for systems placed in service before December 31, 2016; the previous tax credit cap no longer applies.
 
Midalake said:
There does not seem to be too much talk about geo here. So I am building new and my only main heat source options are Propane and Geo. Thus I need to give Geo a Very hard look. The only way it can be installed is closed loop in a lake. Can anyone tell me what is working for them? Any other sites to go to for go info? What are good brands to go with? This whole mechanical thing for the house is a little overwhelming.

Dave
Click to expand...

Just curious, why is the lake your only heat source/sink option? Can't you use trenches or wells?

We have a "standing column" geo system. Its basically a 500 ft. deep well, the same we use for drinking water. Its open-loop and uses the same pump that delivers drinking water although it's sized larger for the geo system. Its been in use for 25 years with the only maintenance being a new well pump in that time.

There's nothing wrong with using a lake for your heat source as long as its large (volume) and deep enough. Its probably the cheapest option if you have the available thermal mass in the lake. Coils of poly tubing are weighted down and dropped to the bottom. You have to do a nice job with where the lines enter and exit the lake to prevent freezing and need to protect against boat anchors.
 
The reason the lake install is the only option is I already have an existing well and house here. I am building in front of where I am now on the lake. I have heard it maybe the cheapest option and one of the best.......due to house position and forested landscape solar is not an option either. The lake is 35 acres in size and 20ft at the deepest point. I own the lake.

Dave
 
Maybe I misunderstood but you said, " my only main heat source options are Propane and Geo". That's total bunk, drive around and look at your neighbors, surely some heat with oil, electric resistance, heat pumps, etc.

Then you said, "the only way it can be installed is closed loop in a lake". That's also false. Trenches or wells are far more typical for geothermal installations. I have seen these wells placed in city lots.

You'll need to start talking to your local professionals about this stuff. You have many options.
 
Midalake said:
The reason the lake install is the only option is I already have an existing well and house here. I am building in front of where I am now on the lake. I have heard it maybe the cheapest option and one of the best.......due to house position and forested landscape solar is not an option either. The lake is 35 acres in size and 20ft at the deepest point. I own the lake.

Dave
Click to expand...

Sounds like the lake as far as a heat source/sink is the way to go; and a great setup in general for a home. Geothermal should be a great option for you. We have a Florida Heat Pump unit which has been very dependable but I"m not sure what they're like today. Waterfurnace has a great reputation as do many others.

This a good geothermal HP site frequented by some knowledgeable folks that you may want to check out.
http://www.greenbuildingtalk.com/Forums/tabid/53/afv/topicsview/aff/13/Default.aspx

One further thought, since you already have propane in place, possibly having already invested in a tank and plumbing, consider installing a hybrid HVAC system using geothermal for primary and propane for auxiliary heat. It can be useful if the geothermal system is down or if you need to warm the place up fast or have unusually high loading. You could also use electric resistance for auxiliary if its cheaper per unit heat than propane.

Have fun with it. I know I would. I'd love to have a lake like yours.
 
Our neighbors have Geothermal and love it. Their pipes run deep into the ground and keep the house around 67-70 year round. Occasionally they will use a space heater in the bedroom.

If I was building - I would consider geothermal, but I also really like my wood heat.

I am confused about the lake. You are in Michigan? I would imagine that lake bottom is cold even in the summer months. How does one gleen heat from a lake?

I guess I need to read up on that.
 
Thanks for the responses so far. I am glad you have a good working Flordia Heat Pump. I know one of my quotes will be using this company, though they do not seem to be highly rated. Yes I will have back ups in case of failure. I do plan on propane for back-up on a millivolt system and I will have a wood burning unit that will heat the whole house if nessary. Keep whats working for you comung and any websites on Geo.

Dave


quote author="Semipro" date="1292371353"]
Midalake said:
The reason the lake install is the only option is I already have an existing well and house here. I am building in front of where I am now on the lake. I have heard it maybe the cheapest option and one of the best.......due to house position and forested landscape solar is not an option either. The lake is 35 acres in size and 20ft at the deepest point. I own the lake.

Dave
Click to expand...

Sounds like the lake as far as a heat source/sink is the way to go; and a great setup in general for a home. Geothermal should be a great option for you. We have a Florida Heat Pump unit which has been very dependable but I"m not sure what they're like today. Waterfurnace has a great reputation as do many others.

This a good geothermal HP site frequented by some knowledgeable folks that you may want to check out.
http://www.greenbuildingtalk.com/Forums/tabid/53/afv/topicsview/aff/13/Default.aspx

One further thought, since you already have propane in place, possibly having already invested in a tank and plumbing, consider installing a hybrid HVAC system using geothermal for primary and propane for auxiliary heat. It can be useful if the geothermal system is down or if you need to warm the place up fast or have unusually high loading. You could also use electric resistance for auxiliary if its cheaper per unit heat than propane.

Have fun with it. I know I would. I'd love to have a lake like yours.[/quote]
 
Before making any choices, especially if you haven't built, you should do a heat loss calculation. If you do that you can evaluate whether your better off adding insulation or investing in the heating system.
 
I have a 5 ton and 2 ton Climate Master unit. I like it. Closed loop in trenches.

My only negative comment, I have a leak in one of my 7 trenches. So far it is very small. If I want to fix it? I need to dig up the manifold underneath the sidewalk built out of pavers, pressure test each line, then dig and replace the line. So put your manifold somewhere you can easily get at it, or put it in a concrete box!
 
My system's manifold is in my basement if by manifold you mean all the connections from the closed loop pipe. The guy that installed it said he would not put any connections underground. So if you are going to put a loop in your lake just calculate the length of pipe you will need to make it all the way from your lake to the unit.
 
Aside from cooling and set a thermostat convenience, how does a geothermal investment compare with a wood boiler? The quote I got a few years ago for geothermal was 40K with me doing the excavation work.
 
I can not imagine having a manifold anywhere other than in the mechanical room. But I need to get more info on this topic, there are too many ways to get to the same conclusion.

Dave



mbcijim said:
I have a 5 ton and 2 ton Climate Master unit. I like it. Closed loop in trenches.

My only negative comment, I have a leak in one of my 7 trenches. So far it is very small. If I want to fix it? I need to dig up the manifold underneath the sidewalk built out of pavers, pressure test each line, then dig and replace the line. So put your manifold somewhere you can easily get at it, or put it in a concrete box!
Click to expand...
 
Obviously we don't have the whole back-story here, but I get the feeling you are focussed on goethermal without exploring more options. If you are looking to heat maily with wood and use geothermal as a back-up my thought is that is a very expensive back-up. Return on investment depends on how much you actually use the system. If wood is available (& solar is not) I'd also look into a high-efficiency wood boiler radiant floor system with propane backup. Not discouraging geothermal, just looking out for your bottom line.
 
midwestcoast said:
Obviously we don't have the whole back-story here, but I get the feeling you are focussed on goethermal without exploring more options. If you are looking to heat maily with wood and use geothermal as a back-up my thought is that is a very expensive back-up. Return on investment depends on how much you actually use the system. If wood is available (& solar is not) I'd also look into a high-efficiency wood boiler radiant floor system with propane backup. Not discouraging geothermal, just looking out for your bottom line.
Click to expand...

I think he said he will have propane and a wood stove for backup. I think that would indicate using geothermal as his primary heat source. He is not looking to heat mainly with wood. He is looking for input/information on geothermal. OK
You know knowledge/first hand experience on geothermal systems. He is not looking for "well I don't know if you would get your money out and that would be an expensive back up or any other like responses"
Just thought I'd throw that out there for ya.
 
There's plenty on this site about geothermal, but first and foremost this place is about wood.

Check your electric rates and see what the KW/hr rate would be. I know a couple people here in NH that regrett the geothermal decision because our rate is $.14/hr or more. Personally I would consider even a 20yr break even payback as a good decision, simply because I'm making about .002 in my savings account.

With a pond that size you should have no problem with a loop. How far from your house is the lake?
 
We are younger upper 40's and we come and go and are on the go so I do not consider a wood boiler an anchor type heating system and no matter where it is located you will be eating smoke at some point. Plus this will be a full log home, and I do not want to be cleaning ash waste off of my logs. Nat gas is not a option so electric and propane are the options, and yes on the cold days I will supplment with wood. I think there are many that do not understand just how long and how cold the UP winters are. Last night for example they said a low of 4 it was -15 when I woke up. Tonight the forcast was for 9 it is already 2. This happens here in the winter all the time. I am leaning for Geo because even with the small place I have now Propane at $2.85 two years ago almost put me in the poor house. As for other factors, my electric here is not too bad here but I do not have the rate in front of me I know we got an increase. I will be building approx. 100 feet from the lake. but the lake is shallow in the beginning, I may have to get out about 300 feet or so the get to the right water depth. I do not know if this complaicates things but I will find out.

Dave


btuser said:
There's plenty on this site about geothermal, but first and foremost this place is about wood.

Check your electric rates and see what the KW/hr rate would be. I know a couple people here in NH that regrett the geothermal decision because our rate is $.14/hr or more. Personally I would consider even a 20yr break even payback as a good decision, simply because I'm making about .002 in my savings account.

With a pond that size you should have no problem with a loop. How far from your house is the lake?
Click to expand...
 
the distance is important because the trench will be expensive. 100' is not too bad. I doubt you'll have to go 300'. 5' under the surface of the ice is probably fine, but I'm not an expert. By the time you get to a point where physical damage is not an issue the loop itself is just pex/poly pipe and not too expensive.

What kind of emitters are you planning? Slab, Forced air, rads?
 
Well I am leaning toward radiant in basement slab and doing the first floor in a slurry mix. I just met with the floor truss people this afternoon and set the plan for that if necessary. Not sure what do for air-conditioning? Can I circulate enough water through the system in the summer to keep the two levels cold enough? We do not have that many days here where we need air.

Dave



btuser said:
the distance is important because the trench will be expensive. 100' is not too bad. I doubt you'll have to go 300'. 5' under the surface of the ice is probably fine, but I'm not an expert. By the time you get to a point where physical damage is not an issue the loop itself is just pex/poly pipe and not too expensive.

What kind of emitters are you planning? Slab, Forced air, rads?
Click to expand...
 
Midalake said:
Well I am leaning toward radiant in basement slab and doing the first floor in a slurry mix. I just met with the floor truss people this afternoon and set the plan for that if necessary. Not sure what do for air-conditioning? Can I circulate enough water through the system in the summer to keep the two levels cold enough? We do not have that many days here where we need air.

Dave
btuser said:
the distance is important because the trench will be expensive. 100' is not too bad. I doubt you'll have to go 300'. 5' under the surface of the ice is probably fine, but I'm not an expert. By the time you get to a point where physical damage is not an issue the loop itself is just pex/poly pipe and not too expensive.

What kind of emitters are you planning? Slab, Forced air, rads?
Click to expand...
Click to expand...

My preference would be heat in the slab and forced air for AC but I could see where you setting might dictate different preferences. I would think that cooling your slab in summer might create condensation and be a safety or water damage issue. I hope your basement slab is, or will be, insulated if you plan to heat it.
 
DO you get many sunny winter days there in UP. Its amazing what a south facing passive solar room will do for you on a sunny winter day. Had mine up over 100 in February with an outside temp of 15. I estimate i get 50%-70% or more of my heat from the solar room on a sunny winter day. Furnace dont kick on till well after midnight.
 
If you dont' need AC then skip the ducting for central air. You can't cool your house by cooling the slab ( I suppose if you had a ton of passive solar and wanted to counter act the effect in the Summer it could be possible) because you can't get rid of the moisture. You end up with a clammy, moldy house.
 
Cal would tell me to keep my mouth shut, but on this site you get what you pay for. If you want somebody to tell you what you want to hear go listen to a politician.

Geothermal with a lake loop sounds great to me. My first thought was that it's hard to justify geo on dollars and cents when you compare it to mild passive solar with slightly improved insulation, but then you go and mention full log construction, so forget about low heat loss. Second thought was that trenches or wells might provide a higher source temp as the lake will get cold fast, not from your heat pump, just from winter. If the lake is 40 and the well water is 55 it might not be that big of a difference, especially since you can throw a lot more pipe in the lake easier than you can add more trench and you're probably going to be looking at a bigger system.

It's awfully nice to have air conditioning here in southern WI, even if we only use it a week a year, but then the radiant slabs would be nice also, I can't help on that one. Another nice feature is a water heating system, either desuperheater, or with a water to water unit that switches between heat and hot water. Again, I can't help with the cost or payback on this, just something to consider.

I've worked with FHP and Tetco, and haven't seen any problems with either in my limited experience.
 
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