Geothermal - Contractor Talk - Professional Construction and Remodeling Forum

Norrrrrrrrrrrrm · 03-22-2007, 08:18 AM

Well milhaus inspired this thread due to his rant........

Does anyone here use geothermal in their house? Do you know anyone who does? What are the benefits cost wise that you/they see? How easy/ expensive is it to install in a home that has already been built?

Driftwood · 03-22-2007, 10:36 AM

Daughter and soninlaw have this buss. in Wash state. You can heat and cool with this. Maybe $40,000 up front. for a good size home. I believe in about 8 years the difference is even. Than a lifetime of savings. They installed it in their rural home. Great comfort,LARGE savings

woodmagman · 03-22-2007, 06:11 PM

Big bucks up front, we just completed a renovatuib where we installed 6- 200 foot holes for the Geo and a recovery sytem, removed the existing concrete floors in the basement and installed infloor radiant with forced warm air over coils on the second floor, when the smoke cleared it was a 70K (Can.) job including demolition and new concrete.

KD@Northeast · 03-26-2007, 03:11 PM

I have also wondered how the system can save you any money heating. Maybe I don;t understand the system fully. The system carries un-heated water down the holes in the earth and brings it to how ever warm the earth is at that depth and then it carries it back to the boiler so the boiler can heat it the rest of the way. I often wondered what the temperature of the water on the return side of the loop of a regular system is and how much the boiler has to work to get it up to temperature. I would love to hear any feed back on this.

Milhaus · 03-26-2007, 11:48 PM

Aha...good to see those rants don't go unnoticed Norrrrrrrrrrmmm!

It's my true calling I think.

I asked one of the heating/cooling contractors here in Iowa a couple weeks back, and he said they were putting them in for $18-30K around here. Retrofit from what I've seen around town....

I don't know about the ease of installation, but I did see them putting a system in beside a house on a super small pad, maybe a 15 by 20 ft chunk of land in between the house and the alley. Impressive.

ah, when I get to build that house....

Woodmag - 200 foot? Is that depth? You ever installed in a pond or a lake? Sounds like a great job to be on.

72chevy4x4 · 03-28-2007, 09:46 AM

one method of installation is to dig a trench (say 8' deep) and lay the pipe like a slinky in the ditch. This way a greater length of pipe can be installed with less drilling as in the vertical method. This horizontal method is good when a large yard is available for installation. A longer run of pipe can be used to compensate for the lower efficiency of running the pipe closer to the surface.

I figured... I could dig the trench (large backhoe) and run the pipe to save on installation costs. Some outfits sell a 'kit' system.

woodmagman · 03-28-2007, 07:43 PM

Quote:

Originally Posted by Milhaus

Aha...good to see those rants don't go unnoticed Norrrrrrrrrrmmm!

It's my true calling I think.

I asked one of the heating/cooling contractors here in Iowa a couple weeks back, and he said they were putting them in for $18-30K around here. Retrofit from what I've seen around town....

I don't know about the ease of installation, but I did see them putting a system in beside a house on a super small pad, maybe a 15 by 20 ft chunk of land in between the house and the alley. Impressive.

ah, when I get to build that house....

Woodmag - 200 foot? Is that depth? You ever installed in a pond or a lake? Sounds like a great job to be on.

That is depth, 6 holes 200 feet deep. Due to limited space that is how it had to be done. Last fall we had 6 lines pushed out under a pond in the front. We have frost to deal with to the 4’ plus mark.

ch0mpie · 03-28-2007, 08:05 PM

I've only seen one job in NYC where they were considering geothermal, but I know a few drillers in upstate NY who tell me that they pretty much keep busy doing only geothermal wells.

Milhaus · 03-30-2007, 12:28 AM

Woodmag - har far did you go down in the pond? I've heard that 8 ft is plenty if you coil it right?

MKamis · 04-08-2007, 08:39 PM

I looked into geothermal for my house, but where I live, you hit bedrock at 2' deep! Too pricey to bore those holes!

I think the systems are a great idea, and if it was more practical to have one, I certainly would.

10-24-2007, 12:30 AM

Geothermal systems are extremely energy efficient (Geothermal heat pumps are more than 3 times as efficient as the most efficient gas furnace, and more than 2 1/2 times more efficient than a 12 SEER air conditioner.) and work to cool/heat your house based on the earth's constant ground temperature.

The majority of cost is due to boring the holes, but once in, it will save you tons of money.

Here's a copy of what's found on our Geothermal guy's site, fyi:

Q: What is a geothermal heat pump?

A: A Geothermal Heat Pump is an electrically powered heating air conditioning system that uses the natural heat storage ability of the earth. In Texas the ground temperature 6 foot down stays a constant 68 to 72 degrees.
Q: How does it work?

A: Like any type of heat pump, it is simply moves heat energy from one place to another. Your refrigerator works using the same principle. By using the refrigeration process, a Geothermal heat Pump removes the heat from the home and transferred to the ground.

Q: How is heat transferred between the earth and the home?

A: The earth has the ability to absorb and store heat energy. To use that stored energy, that constant 68 to 72 degrees temperature is extracted from the earth through a liquid medium (water) and is pumped to the heat pump or heat exchanger. In the winter, the heat is used to heat your home. In summer, the process is reversed and indoor heat is extracted from your home and transferred to the earth throughout the water.
Q: You mentioned heating and cooling. Does it do both?

A: One of the things that make a heat pump so versatile is its ability to be a heating and cooling system in one. You can change from one mode to another, just like you do on a conventional heating and air conditioning system via a thermostat.

Q: What types of loops are available?

A: There are 2 main types of loops: open and closed. The closed loop is the most common in Texas. The same water is circulated throughout the entire system. An open loop is used when a water table, such as a river, lake or a pond is used for the water source.

ConstSvcs · 01-24-2008, 07:12 PM

A well drilling contractor set up for drilling waterwells is the wrong direction to go if you are looking for a GEO-T well. The drill hole dia. used for well pumps is not needed for geothermal installs. My contractor has even used self-propelled rock drills with quarry sized drill steels for difficult to access sites.

orson · 01-24-2008, 07:44 PM

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waterwell · 01-24-2008, 10:30 PM

Quote:

Originally Posted by ConstSvcs

A well drilling contractor set up for drilling waterwells is the wrong direction to go if you are looking for a GEO-T well. The drill hole dia. used for well pumps is not needed for geothermal installs. My contractor has even used self-propelled rock drills with quarry sized drill steels for difficult to access sites.

This is only correct on a closed loop system. Even that is not entirly true a six inch bore hole from a water well rig folowed with thermal grout has better heat distribution, better than that of a small 3" or 4" hole from a quary drill. It does cost more of course for a drill rig but this is about efficiency not economy in instalation, it is all a return in investment.
Our company has installed Geo wells for over 10 years now and are very educated in this field any questions feel free to ask.
we deal typicaly with open loop systems, which require one well for the geo system and domestic water usage and one variable speed pump system.

cleveman · 01-26-2008, 08:45 PM

kd@northeast:

read a brochure from some of these guys. There is a firm in Monroeville, PA which makes the equipment. You're not using the heat from the ground to heat the water/air directly, but indirectly through the same process as refrigeration. Some substance is going through the liquid/gas/vapor process as it is being compressed. It's temperature is affected by the compression. Let's say it comes in warm, then is zapped by the compressor and turns really cold, but this energy is released to make something else much warmer. So you use this "much warmer" to heat your air/water, and send the "much cooler" back down into the ground/water. In the summer, the system is reversed.

So it is not just the temperature from the ground, but also the electricity used to run the compressor and some magic substance which changes from liquid-gas-vapor and back again.

I don't know if I've spoken intelligently on the matter, but I do think it will help you understand it. I can't say that I have more than a rough working knowledge of the process, but a great desire to run my mouth.

RizzoMaryland · 01-27-2008, 08:17 AM

Any ideas on new construction costs? 3 ton unit/3500 sq.ft. house

**joasis** · 01-27-2008, 08:53 AM

The quote on my new home is 21k with a split system and hot water recovery. 3400+ sq/ft. 5 wells...and this is Oklahoma.

monsterconstruc · 01-30-2008, 12:41 PM

We are currently building a green home for ourselves. Geothermal was our perfered choice before we found out about Daikin air conditioners. They use 15% to 50% less energy than geothermal using zone technology. For example, at night when your in bed, you dont want your kitchen, living room etc. being the same temp as your bedroom. Daikin system will reduce the power of selected zones in your house that your not using. So the kitchen and living room will be running at 10% and your bedroom at 30%.

Norrrrrrrrrrrrm · 01-30-2008, 09:23 PM

Quote:

Originally Posted by monsterconstruc

We are currently building a green home for ourselves. Geothermal was our perfered choice before we found out about Daikin air conditioners. They use 15% to 50% less energy than geothermal using zone technology. For example, at night when your in bed, you dont want your kitchen, living room etc. being the same temp as your bedroom. Daikin system will reduce the power of selected zones in your house that your not using. So the kitchen and living room will be running at 10% and your bedroom at 30%.

Do you have any prices/guestimates on these? I don't need anything larger than a two ton.

monsterconstruc · 01-31-2008, 12:18 PM

I currently do not have pricing for a 2 ton system. I would speak with Ed Fritz. He is an engineer with Daikin and will be able to answer any questions you may have. You may not need a 2 ton system when using the Daikin system. You can contact Ed Fritz at 972 245 1510.