Geo Thermal heat Pumps

[sepefrio]

While driving and listening to the radio, there was a "Ask the Expert" show on. It was an HVAC guy talking about Geo Thermal heat pumps and how they are the best thing out there. He said the unit he installs is an almost 30 seer unit and one customer with about 5000sf house only spent $500 in electrical bills.

Has anyone heard about Geo Thermal units or have any good article/literature I can take a look at?

[hausdok]

Ahem,

https://www.inspectorsjournal.com/forum ... IC_ID=4609

Searching before asking can save a lot of time.

ONE TEAM - ONE FIGHT!!!

Mike

[sepefrio]

Sorry, I should have looked. But I guess I also didn't get my question across properly. I've found a lot of general information about them, like the link you gave me. I was referring more to the inspection of such a system. Since a lot of it is underground, not much we can do there. Also, the I assume the ducting would be the same, but is there anything special to look at on the heat pump itself.

I actually think I'm going to call the guy from the radio show and ask him if he can show me a thing or two.

[Jim Katen]

Originally posted by sepefrio

While driving and listening to the radio, there was a "Ask the Expert" show on. It was an HVAC guy talking about Geo Thermal heat pumps and how they are the best thing out there. He said the unit he installs is an almost 30 seer unit and one customer with about 5000sf house only spent $500 in electrical bills.

Has anyone heard about Geo Thermal units or have any good article/literature I can take a look at?

The proper term is "ground source heat pump." They merely use the earth or an underground water source as a heat sink. A genuine geothermal heating system would rely on some sort of active underground heat source and wouldn't typically be used for a single family home.

I've seen several of these systems. In my area, there was a guy who specialized in designing, building and installing them. He literally built them in his shop from off the shelf parts and put them together in sheet metal cabinets that he fabricated himself. Some of these systems have been running well for 30 years now. Unfortunately, he passed away a few years ago and the people who own these systems are having a tough time getting someone to service them.

I inspect them the same as any other heat pump. Most of my inspection involves looking at the temperature differentials in both heating and cooling. In cooling, I always take relative humidity into account.

- Jim Katen, Oregon

[Brian G]

Originally posted by Jim Katen

A genuine geothermal heating system would rely on some sort of active underground heat source and wouldn't typically be used for a single family home.

Huh? You lost me there. I've been lusting after one of these systems for the the last few years, so I've read whatever I can find on them. They simply use the differential between the outdoor air temperature and the ground temperature at a particular depth (which varies by region). Some use the water temperature in lakes instead of the ground, but those are the exception rather than the rule. What "active" heat source did you mean? Are you thinking of the kind of large, public-owned systems they have in Iceland?

And while there are very few around here, all I've seen were on single family homes. These are going to be more and more common on SF houses as energy prices continue to rise (they will), and installations methods evolve (they already are).

I can't say I've ever seen anything written about inspecting them. I do have a few links, for what they're worth:

http://www.ecrtech.com/home

http://www.copper.org/applications/plum ... _main.html

http://www.geoenergyusa.com/technology.htm

Brian G.

Whut 'Chu Talkin' 'Bout Willis?! [?]

[Jim Morrison]

Someone should try to capture the heat from the hot air Saints fans blow at the beginning of each season. I bet I could heat my house for a year with just three or four of 'em!

(if there actually were 3 or 4 Saints fans left, that is)

[msteger]

I've seen several of these ground source heat pumps in my area in the past 6 or so years. These systems are not cheap, but seem to work very well and last longer than an air source HP. No compressor to wear out either.

Several schools in this area have been moving to these types of systems and even are installing them under their soccer fields. Companies that do well drilling can also do the drilling for these systems. From what I recall, the refrigerant is a mix of ammonia and a few other items (and part water, I recall). I do the same inspection on these as I do for air source units. Run the unit and take temp measurements. There isn't much to see other than where the refrigerant lines enter the home and looking at the air handler. I've only happened to inspect homes with ground source heat pumps in the summer, so I've only ran the unit in cool mode, however, I would expect we can run these in heat mode as well.

My dream HVAC system would entail a ground source heat pump system with natural gas fired backup.

[Jim Katen]

Originally posted by Brian G

[navy]. . . What "active" heat source did you mean? Are you thinking of the kind of large, public-owned systems they have in Iceland?[navy] [?]

Yes. I distinguish between a ground source heat pump, which uses the ground as a heat sink, and a heating system that actually takes its heat from undergroud hot springs or steam sources. Here in Oregon, the town of Klamath Falls uses geothermal heat for many of its government buildings and they have ample left over for a public sidewalk snowmelt system.

I've heard that they have similar setups in Iceland.

- Jim Katen, Oregon

[Brian G]

Originally posted by Jim Morrison

Someone should try to capture the heat from the hot air Saints fans blow at the beginning of each season. I bet I could heat my house for a year with just three or four of 'em!

Hey I got burned on my own hot air so bad last year, I ain't said squat this year. Besides, Red Sox & Patriot fans are much better sources. []

Brian G.

How 'Bout Them Rays?! []

[Brian G]

Originally posted by Jim Katen

I've heard that they have similar setups in Iceland.

Yeah, they have a ton of that type of thing there. It's a strange land, with two continental shelves meeting right across it. Glaciers and lava in the same place. I'd love to go there someday.

Brian G.

Note To Self: Pack Warm [:-cold]

[energy star]

Originally posted by msteger

I've seen several of these ground source heat pumps in my area in the past 6 or so years. These systems are not cheap, but seem to work very well and last longer than an air source HP. No compressor to wear out either.

They have a compressor. You mean to say they do not have a condenser. (That is, exposed to the elements. It's in the ground)

[msteger]

Sorry.. I stand corrected.

I also wanted to ask - Since ground source units don't have to 'find heat' in the air in heat mode, do these systems not need a backup source (for colder weather) since the ground stays warm even when the air temp can be 10 degs F?

[energy star]

Nope. 55 degrees all the time.