experience with geothermal heating?

Dawn

I have been bouncing around a few ideas for heating our home. I would love to install a woodstove, but I don't see how I could possibly add one to this house... Unless, I add a stove to the outside of this home and attach it to the ductwork. I have seen that before, however, I think those were corn burners and not wood. I also do not have any mature trees in my yard and worry that many people soon may be relying on wood as a source of heating/cooking.

Anyway, I am seriously considering geothermal and one of my neighbors is an installer of geothermal for a company... He gave me an estimate about 10,000 - 14,000 less than the larger companies. Hum, around where I live the electric company charges about half the normal rate to operate these systems.

As a back-up I would also like to install a turbine to generate electricity. I'm just waiting for the township to pass the ordnance that would allow me to put a turbine in my yard.

What would you do? Any thoughts or ideas?

TIA

purdum · Tar Sands Joined: Feb 15, 2005 Posts: 34 Location: MI, USA

Just working some numbers through my head, I think you would need at least a 10-15kw wind turbine to meet peak winter heating demand. I am near Lansing and have a geothermal system installed. PM me and I can give you details.

deMolay · Intermediate Crude Joined: Sep 04, 2005 Posts: 907

Geothermal is very expensive here in Alberta. Above 30,000 dollars. I think the piping and system would be worn out before you got payback. It is also realatively high tech and expensive to maintain.

WisJim

In addition to expense every "geothermal" heating system--I am assuming you are talking about ground source heat pumps--have had compressor and /or control problems, and there aren't a lot of people that know how to fix them. Insulation is cheaper.

Ludi

I agree, wisjim. I know I'm not really qualified to respond to this thread because I live in a warm climate, but, if I had that kind of money to put in a geothermal system, I would instead use it for insulation, quality windows, and a small efficient woodstove. Our house is horribly insulated with miserable windows, and we heat entirely with a small woodstove.
_________________
"...powerdown so soft and fluffy you'll think you're living in a pillow." - jboogy

Madpaddy · Expert Joined: Jun 25, 2004 Posts: 2130

I have specified and installed geothermal in a building where I work. It is performing very well so far but I have to say that retrofitting geothermal with underfloor heating to an existing house is not worth the trouble. I second the more insulation proposal.
_________________
www.askaboutenergy.com

Dawn

purdum, I will be PMing you shortly.

Has anyone ever added a woodburner to an existing home? If so how did you do it? There are so many options out there it is almost overwhelming to sort through it all. This house is fairly new, but I also have thought about getting estimates for having insulation blown into the walls.

Currently we use propane and it is getting to be very expensive. Let me see, I just locked in propane at the rate of 2.32 per gallon for this upcoming winter and if this year is anything like the last we will use around 1400 gallons. So, that's 3248 plus tax. My neighbor will do the install for 16000. It doesn't sound like that many years until I'd break even. Last year I didn't have the option to lock in the rate and the bill ran anywhere from 600-700 monthly.

I didn't plan on having water pipes installed under the floor... Though it would be possible to do so in the basement to warm the first floor. The unit can be attached to existing duct work and the warm or cold air is blown just like the typical furnace. Here's a link that shows what I'm talking about.

Madpaddy · Expert Joined: Jun 25, 2004 Posts: 2130

You must have an enormous house or else it is very poorly insulated. I don't see what the problem might be fitting a woodstove. A flue can be installed anywhere in the house.

http://www.stovesonline.co.uk/fluedesign.html
_________________
www.askaboutenergy.com

Dawn

To be fair the 1400 is for the whole year, as we haven't had a fill-up since last Spring... It's coming up soon though... Also, last year was cooler than usual for this area. The house is rather large, plus the basement which needs atleast some heat so the pipes don't freeze.

Another thing that I've been considering is changing the stairs coming into the home into an enclosed porch. I think for us that's the big waster of energy... When they open the front door the cold air comes rushing in. If it were enclosed it should help a bit.

The only place for a woodstove here would be in the kitchen because they are supposed to be away from the stairs, correct?

nocar · Intermediate Crude Joined: Nov 05, 2004 Posts: 689

I have ten years of experience with a ground source heat pump, and for us it has worked very well. We recovered the initial cost several years ago.

Only thing to regret is not drilling the hole or shaft deeper.
We got a 90 meter hole (perhaps shaft is a better word, it is about 20 cm in diameter) which was the most cost effective at the time. Now, with electricity more expensive a deeper shaft is more cost effective. The drilling of the shaft was the expensive part. The compressors and other stuff about a third of the cost.

For us, there were several things that made it advantageous

- we used to heat with oil and as that system had to soon be replace anyway being 40 yrs old at the time

- the system alread had water circulating in large radiators which did not need to be replaced. Large radiators are good because the give a lot of heat even if the water is not so very hot. It is less efficient to make the water hotter.

- our house is located on a good Swedish granite bedrock, with water moving around inside it. It is important that ground water circulate in the shaft to give off its 'heat' (around +6 C)

- The Swedish companies installing ground source heat pumps have realised that people's confidence in being able to get problems fixed is very important so they guarantee service. So far we have had to contact them about three times over ten years. Often they can tell you on the phone what to do, what buttons to press.

- our winters are long, with heating season from middle September through most of May, but we have only a few short periods with temps under - 4 C. At those temps, lot of extra electric power is needed. That is when the extra capacity of a deeper shaft is a lot better, and that is what people now install, 120 meters usually. With two shafts if the house is big.

In other words, for us the system works very well, and now it seems that most houses on our street have installed ground source heat pumps. But your situation could well be different.

-------------------------------------------------------

Of course, if your house is poorly insulated, that should be fixed in any case.
-------------------------------------------

nocar

Mechler

I was telling someone in another thread about gasification wood boilers - which is something that could solve your problem. I'm no expert, but I've been researching heating systems for a home we're buying in upstate NY. I've come up with three possible solutions:

1. Geothermal heat pump connected with a pond by the house and/or a horizontal loop. This is much cheaper than vertical loops because no drilling is involved. Efficiency may decrease, though, so I'm still looking into that.

2. Gasification wood boiler connected with a thermal mass (big water tank). Apparently, gasification wood boilers burn at very high temperatures and are very efficient. Connecting it to the water tank allows you to run the boiler at high temperatures and store the excess heat (instead of damping it down, lowering the efficiency and creating more pollutants). You also only need to fire it once every day or two. The cost of a system like this can be high, but probably cheaper than geothermal.

The boiler can be placed in the house or in an out-building, which adds some flexibility.

3. Solar hot water space heating. Basically the same as the boiler above, except that the sun is creating the heat instead of wood. This system has to be backed up by a traditional boiler or water heater and probably works best with lower temperature applications like radiant floor heating. This is probably the cheapest option, but will only supply a portion of your heating based on size of the system, amount of sun, etc.

The house I have already has a wood stove and the basement is apparently already piped for radiant floor heating, so I'm leaning towards the solar option. If anyone has any thoughts on this, please let me know.
_________________
"It is certain that free societies would have no easy time in a future dark age. The rapid return to universal penury will be accomplished by violence and cruelties of a kind now forgotten." - Roberto Vacca, The Coming Dark Age

IslandCrow

I have a ground heat exchange pump....deep hole in the ground, which took a day to drill. It has worked well and I am happy with it (we have now had it for about two years).

The house had a very old oil heater (over 30 years!) and given the cost of replacing the old heater, and the current oil prices, the payback period is about 5 years (on an investment of over 16 000 euros). So if it lasts at least that long I will start to get substantial financial advantage from lower heating bills.

The electricity companies reckon that a house this size (around 140 sq meters) if heated just by electricity should use 28 500 kW a year. The dealer estimated that our system should provide the same heat for 7 020 kW (under 25%), and due to a mild winter, (and not being here all week), last year we used 4 500 kW for the heating and hot water (between 35 kW in summer, to nearly 1 000 kW in cold February, when the heat pump ran for over 60% of the month).

I believe that if you have the money available, a ground heat exchange is a good investment, but it does take a lot of money at first.
_________________
We should teach our children the 4-Rs: Reduce, Reuse, Recycle and Rejoice.

Pops

Just my couple of cents; heat pumps blow air only a degree or two warmer than the interior air - it's like indoor wind chill.

Check your infiltration, insulation and get a corn/pellet burner stove for back-up if you have cash left over.

I like radiant heat, from the floor preferably but any flame is better than a wind blowing a few degrees more than ambient.

Again, just my experience.
_________________
Make a plan and work it:

nocar · Intermediate Crude Joined: Nov 05, 2004 Posts: 689

Pops, you must be referring to heat pumps using outdoor air as the 'heat' source. I agree, that is a ridiculous concept. In cold weather you need more heat but the source has less.

Ground source heat pumps are much better, as the ground temp stays the same all year. And modern systems can be used for cooling in summer. (Ours is not set up that way, and we do not need it in our climate)

nocar

deMolay · Intermediate Crude Joined: Sep 04, 2005 Posts: 907

If you look at some of the systems build by the Romans, passive reclamation of heat and cooling from the earth, I think you would be on the right track. I remember reading an article on it in Popular Mechanics or Mother Earth News years ago. No moving parts no high tech gadgets no electricity required.
_________________
"Since you have chosen to elect a man with a timber toe to succeed me, you may all go to hell and I will go to Texas." Davy Crockett