DX Geothermal Standing well

Allen Grayson

Has anyone had any experience with, exposure to or a thoughtful opinion upon using DX Geothermal heat pump with a standing well of water.
Thanks in advance

Jack_21

depend on the flow gradient of the well

Depending upon the flow rate you are running the equipment at and the actual "flow" of the water within (across) the well it can be done. For instance, In Klamath Falls, OR they use direct geothermal for space heating in many homes. The underground hot water actually flows across the downhole HX (hairpin of 1 1/2"-2" pipe). Usually however, you "cold cap" a well and the system stops working. The most common type of well system is one well to supply and one to re-inject (don't forget to check with your local water quality resources people. they have no sense of humor). Normally, you try to reinject into the same aquifer level. You should be able to get additional information from the Geo-Heat Center at the Oregon Inst of Tech in Klamath falls

Allen Grayson

Clarification of original question

Obviously I've not stated my question clearly.

What I meant to ask was does anyone have any experience, exposure or thoughtful opinion on the application of the following type of system?
1. Heat pump with copper tubing inside of a standing, closed column of water.
2. This would be a type of closed loop, Ground Loop Heat Pump with vapor inside of the copper tubing - thus direct expansion.
3. Standing water column is approx. 2' dia. & 2o' deep - starting 2' below the ground surface.
4. Water containment is via a plastic type of flexible wall tank.
Sorry for the confusion.
Thanks in advance.
Allen Grayson

Constantin

I'm not sure it would work...

... I have no experience with DX or any GSHP for that matter. However, I doubt that the well will provide enough heat transfer not to turn into a snowcone in short order (or a tea-kettle, depending on the season).

Every DX system I have seen feautured long, narrow boreholes going off at angles to maximize the ground volume that the pipes could influence. Regular closed-loop systems that rely on water have something like 10' between boreholes, minimum, and those pipes go down hundreds of feet.

So, unless you have a underground river flowing through that shallow well, I doubt it can be done.

Marty_2

I've replaced more than one well based dx system due to problems outside. 3 biggest issues are leaks after 7 years or so , if the piping isnt perfect oil winding up outside and not in its happy home in the compressor and last the cold capping or freezing up outside. Unless you were getting fantastic thermal transfer between the water and ground you might wind up with a 2000 gallon icecube

Henry_6

Geothermal DX

> I've replaced more than one well based dx system

> due to problems outside. 3 biggest issues are

> leaks after 7 years or so , if the piping isnt

> perfect oil winding up outside and not in its

> happy home in the compressor and last the cold

> capping or freezing up outside. Unless you were

> getting fantastic thermal transfer between the

> water and ground you might wind up with a 2000

> gallon icecube

Henry_6

Geothermal DX

I have had the "pleasure" of retrofitting a commercial office building in the Boston area which was DX well based and replaced it with a more conventional propylene glycol system which works. The original system had the well pumps upside down to "increase heat output" In a word, wrong! The replacement system was Cantherm and operated with latent and sensible heat for winter by freezing the boreholes and generating 60 tons of cooling in the process. Unfortunately, American manufacturers are not willing to put the money for heat exchangers in the box to enable these systems to be sold here.I would not recommend DX for another reason. Static electricity generated by the liquid refrigerant and the ground will cause brazed fittings to fail. This will not happen with Sched 40 or equal tubing. As Dan has noted in the past, the failure rate with copper in concrete for radiant heating ended up being automatic because of static electricity. Check with IGSHPA in Oklahoma for recommendations on geothermal. They can provide heat at- 20 to -30 F if properly designed.

JimGPE_3

Best bet?

Contact the factory. They're usually pretty experienced and helpful. Water Furnace has been pretty helpful.