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Geothermal Heating/cooling question

Started by Typhoon, March 03, 2004, 03:14:20 PM

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Typhoon

Well, my wife and I are getting ready to build a log home next spring. We are making alot of decisions of course, and one of them is dealing with the geothermal/water furnace heating/cooling system where they drill the wells and stuff. Anyways, I was hoping there would be a few ppl on here that have this system and can comment. Or even if you dont, and if you know something about this subject, feel free to comment. The home is 2400 sq. ft + a full basement. So probably looking at a 4 ton unit. I know the initial cost is higher. Thanks for any input!
Brad Dawson, Anna IL (Southern tip)
Husky 346xpNE, Husky 357XP, Norwood Lumbermate2000

Corley5

I had plans to install a geothermal system when I built my house.  One thing that everyone told me is to stay away from the ones that use well water.  Your equipment life is shortened because of mineral deposits.  They instead recommended a closed loop system that takes heat from the earth instead of ground water.  Tubing is buried in your yard and fluid ran through it to collect heat.  It was also cheaper to install and cheaper to run as I wasn't going to have to pump water from a 150' down.  
Burnt Gunpowder is the Smell Of Freedom

J_T

I vote with Corley . Here to use well water you better have a nickel stanless coil no copper our water will eat it up in a few years . For my use I want a wood fired boler. Even free I don't want the other in this area.
Jim Holloway

beav

Make sure most of your windows face south.This is the simplest,cheapest heat. Next a woodstove, then a wood/oil boiler. Anything else is too complicated :)

DR_Buck

I did a lot of research on geothermal a few years ago.  I was going put a system in myself.  However, ran out of cash doing other remodeling and settled for a standard heat pump.  

There is a lot of information out on the web.  Just do a search on geothermal.   Definitely go with a closed loop system.  It requires less solenoid valves, doesn't have the mineral deposit problem and is less expensive.  No additional wells to drill, which can rob from your drinking water supply during a dry season.  Other than the air-handler/heat exchanger, the biggest cost is the special plastic pipe that gets buried and the cost of digging to the required depth.  In my geographic area that is about 4 1/2 feet down and required about 2500 ft of buried pipe.

Good luck with your research.
Been there, done that.   Never got caught [/b]
Retired and not doing much anymore and still not getting caught

Minnesota_boy

I built my home with hot water baseboard radiators to use with a wood fired boiler.  Really quiet and even heat.  20 years later I wanted to replace my wood fired boiler with a geothermal heat pump and talked to several heating contractors about it.  Most didn't know as much as I did about that type of system and were no help at all.  Finally found one who knew what i wanted and he said "No go" because the heat pump could not provide me with hot enough water to heat my house with the baseboard units.  

I ended up with an "off peak resistance boiler" and a high efficiency propane furnace for backup.
I eat a high-fiber diet.  Lots of sawdust!

slowzuki

In Manitoba the power company has become a big fan of heat pumps I think to avoid having to build new generation facilities.

The # of new installs per year is more than doubling each year.  Building a base of qualified contractors is key to success!

I recommend water-water units.  All the coolant comes sealed in from the factory in this type.  No soldering of refridgerant lines or charging on site.  Less to go wrong.  The unit has four water lines on it. A pair to the house, a pair to the outside.

Some have a heating loop so when you are rejecting heat in the summer in can heat your domestic hot water too and save some $$.


Do your homework sizing them, plan to use auxillary heat to meet demand for the coldest days.  They are most efficient when they run fairly long per cycle.  

If you oversize to handle the coldest day without auxillary heat, on regualar days the unit will start and stop all the time wasting power.
Ken

Larry

When I built 14 years ago, I thought about geothermal but the payback was too long and the technoloy too new for us to risk it.  We went with air to air heat pump with propane backup.  B-I-L built 5 years and went with geothermal total electric.  Closed loop system with the pipe in a trench.  He is happy and saving money right now.  My house is 2,100 sf. while B-I-L's house is 2,600 sf. with similar insulation.  His electric bill is less than my bill every month.

Our electric company is one of the REA companies.  They really push the ground source heat pumps and will work with anybody building to figure out the payback period, best methods, and have a list of reliable contractors.  I would start my research with a call to the local power company especially since the price per kilowatt hour determines the payback.
Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

Tagerts_crossing

I think if it is poss. on your site and you have the wood to burn the outdoor wood boiler is hard to beat.  I understand that its not for everyone tho.   John
John Schoolcraft

D._Frederick

The earth furnaces will give you about 3 to 4 time the BTU of electrical resistance heating, but there are two problems, the initial cost is high and also the up keep cost. You can figure on replacing the compressor about ever 4 to 5 years. The field installed compressor will last even less.

Faron

I have an outdoor woodburner that pumps hot water through a radiator in my furnace ducts.  My plan is to install a loop and pump cool water through that radiator in the summer.  Anybody tried this?  By installing the pipe 5' or so underground, I ought to be able to cool the incoming water to 55 degrees or so, I think.    Faron
Democracy is two wolves and a lamb voting on what to have for dinner.  Liberty is a well armed lamb contesting the vote. - Ben Franklin

wiam

I have an outdoor boiler with heat exchanger in the ductwork.  I have hooked up an unused spring to the exchanger with about 60 degree water with moderate success.  Not like real AC but it helps on very hot days.
Wiam

slowzuki

Many compressors have a 10yr warr. on them.  The older ones were not as reliable.
Ken

QuoteThe earth furnaces will give you about 3 to 4 time the BTU of electrical resistance heating, but there are two problems, the initial cost is high and also the up keep cost. You can figure on replacing the compressor about ever 4 to 5 years. The field installed compressor will last even less.

Typhoon

Well thank you all for the replies!! This is what I have come up with so far. (Actually my dad and I both came up with this info because he is actually building a house as we speak, and he has decided to go with geothermal). We have found that the geothermal units are extremely efficient as you probably already know, because you are using 55 degree water coming out of the ground to either heat or cool with. The efficiency cannot be beat. However, the downside is the initial cost. But, I think we have found a way to beat this. I won't go into naming brands or companies for obvious reasons. But here are the numbers in case any of you might be doing this soon.
All of this information is for a 2,400 sq. ft. log home with a full basement.
First, we priced both a conventional and a geothermal unit, FULLY installed. After doing some shopping, we found that the conventional unit would cost $7,000.00 installed. The geothermal unit would cost $18,000.00 installed. This is where it gets interesting... we found that nearly HALF of the cost of the geothermal units lie in labor alone. The actual 4 ton unit costs approximately $5,500.00. So to make a long story short, we are going to do most of the work ourselves outside of drilling the 4 wells. (Ductwork, electrical, etc). The unit completely installed and running will end up costing a grand total of $11,500.00.  Thats not bad. Much better than the typical $18,000.00.  The thing that really turned me on to these, is I have a friend that built a 2500 sq. ft. house about 8 years ago. He initally installed a conventional unit, then later installed a geothermal system. The most expensive time here in southern illinois is mid-summer, when it is about 90 degrees and humidity is 80% or higher. His electric bill was running  between 250.00 - 300.00 mid summer. His electric bill after installing the geothermal unit is 75.00 mid summer. Thats great savings! So we have decided to go for it.  Thanks for the info guys!
 :)
Brad
Brad Dawson, Anna IL (Southern tip)
Husky 346xpNE, Husky 357XP, Norwood Lumbermate2000

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