I’m building a house in an area with 20F winters and 80F-90F+ summers and considering Geothermal heating/cooling instead of a heat pump. No natural gas is available but electricity if fairly inexpensive. Anybody have any thoughts about this?
I understand it is very expensive. I was told it would cost about $10,000 per ton and my house will be about 4,000 SF needing about 3-4 ton.
Replies
You'll find lots of info in the archives.
Personally, I have a great system that was poorly engineered. It works great down to about 18 degrees. Then it can't keep up. I've since backed it up with a wood fired insert with remote blowers and life is good.
So, don't skimp on the engineering.
I'm just finishing a geodesic dome that sports a 4 ton unit along w/water superheater. The pipe field is layed out on about a half acre.
Cost of that system was a little over $16K, including forced air system, so the $10K per ton sounds a little steep, but where you are and site conditions could certainly influence cost.
Pretty mild winters here in the PNW but the geo gives you pretty consistent performance regardless of outdoor air temps...but I'm sure you know all that.
They're just catching on around here because we've enjoyed cheap electricity for a long time. I know of a couple of other systems locally that have been in for about 5 years and the owners seem pleased.
I agree with the other post that stresses competent engineering, and that includes the actual heat distribution system.
Where are you located? I'm in Des Moines, WA and the project is in Leavenworth
North Bend, OR, on the coast...I thought Des Moines was in Iowa? :-)
What was the length and depth of your trench?
5 trenches, 8' deep, 400' long, 2 loops in each trench...total about 4000' of pipe to a distribution manifold and then about 200' to house.
(I wasn't the installer...local sheetmetal shop put in the heatpump unit and distribution system; the loops were layed and joined and the system filled and purged of air by a company in Roseburg, Oregon.)
I have a Five ton geothermal unit that I bought from a company in lakeland Florida called ECR Technologies. It is a Direct unit so it uses no water no heat exchanger. I think I have about $5500 in the equipment which included a heat recovery unit for heating the house water during the summer cooling season. That price did not include the duct work which I bought from a local sheetmetal wholesaler or the main copper tubing that connects the manifolds in the pit with the compressor unit (heat Pump). So far the unit works great in both modes however I cannot give you details on the cost of running the unit because I am not anywhere near done insulating the 2200 sq. ft. house it serves. I have mounted the heat pump in the basement equipment room alongside of the air handler and ran the suction lines and liquid lines through the basement wall to the 50' by 50' pit where the 24 1/4" by 100' copper field lines are buried approximately 4' deep. I had a friend of mine help me with the installation of the system which came with a very detailed instruction book. With the duct work, pit excavation, equipment, and labor to braze and charge the unit I think I have about $7500 to $8000 in it. I can highly recommend this company. Their web sight should be at: ecrtech.com
This winter we had 110 to 130 degree discharge air.
>I was told it would cost about $10,000 per ton
I also find that high. The ballpark number from the guy I work with is 4K per ton if trenching...a bit more for vertical. We have a similar temp range here in Western NC and ours works great year round.
I have a 3.5 ton unit with 4 wells dug at 150 ft deep at 3.25 per foot. Three zones with programable thermostats, humidifier, air cleaner and I added on a Energy Recovery unit to replace stale air as I have Icynene insullation and felt it would be too tight otherwise. My total cost installed including the wells is about $13,000 or so. Not quite finished yet. I'm located in Central PA. My unit is a Trane which also has a feature on the control board allowing to change the unit to a 3 or 2.5 ton unit which slows the air velocity down which in tern will bring up the air temp. This past winter another customer was complaining about the cold air feeling on a 20 degree day. He slowed down the air flow and incresed the heated air temp from 83 degrees to 100 degrees.
Good luck
Rupert
I see 10K per ton out here in CO.
Please consider maintenance costs. They can be a KILLER as many have found out. Go in with your eyes WIDE open. Don't buy into all the hype (and lies) the promoters spout off. Listen to both sides of the story!
Then... if it still makes sense to you go for it!
What maintenance cost? I didn't know there were any on ground source systems.......Ambiguous headline: TWO SOVIET SHIPS COLLIDE, ONE DIES
Mechanical and electronic systems failing within a few years.
One client showed me a written quote of around 5K on a 10 year old system.
Thanks fer the info - Had never heard that before.The day Microsoft makes something that doesn't suck,they'll be making vacuum cleaners
It is not "politically correct" to point that out in this day and age.
I am all for energy conservation. Big time!
But...
MUCH of what is so worshipped today is a hoax. Geothermal, tankless water heaters, etc. I am not saying these systems are hoaxes. They are wonderful ideas. The hoax part is what the greenies (and the wanna-be-greenies) make them out to be.
A FAR better use of your extra money would be to upgrade your windows and doors and to use a product like Corbond for insulation. Then put in a high efficiency, well controlled, conventional heating system. You will see similar if not better energy savings at a similar or less upfron cost with lower maintenance costs.
I tend to roll my eyes at those who promote geothermal as being the all-in-all for HVAC because they usually are un-informed or else have an agenda which has nothing to do with energy savings.
Like builders... what is their agenda? To make more sales by looking green with a popular method of loooking green. I honestly think 95% of the promotion of geothermal is all about the money.
I like the systems if designed and used correctly in the right application.
>I honestly think 95% of the promotion of geothermal is all about the money.
My perspective is really different. All I've heard around here is that when the elec rates are favorable, and gas is not readily available, it's a good alternative. Haven't heard "green". It's done us well and nowhere near the $10K/ton. How does that break down? It can't be the heat pump itself, be/c that would be fairly constant around the country. So it has to be either the trenching or drilling or labor. Big, big gap.
I see 4 ton units selling for 15 to 20K
I may be a bit exView Imagetreme on the 95% number but I still hold to the general opinion quite strongly.
I say this...
Put your money in a fully modulating, high effiency gas furnace.
Couple this with a high SEER AC side.
Zone it correctly
Use Corbond to insulate with (thick layer)
Upgrade your windows to very efficient windows.
Now... put this home's energy life cycle costs up against the standard home with Geothermal. Can't prove it but I would almost guarantee my home would have the lowest energy life cycle cost by far.
I like not burning anything or having to have gas. Pain in the neck up here--no piping and didn't want to find room for a tank. Maybe you see hype, but I never have. Just a solution that works well under certain circumstances.