[QUOTE=Gross;11796162]So what you are saying is:
Since DX runs refrigerant through the loop... the temps are wider and as such X-fer works over a wider soil temp?
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Interesting link.
Do folks bury ground horizontal loops with the coil method... had not read much about that.
Most of what I hear in my area: Contractors do wells. Generally one 150-200' deep well per ton. Problem is... it requires lots of permitting (multiple agencies have to approve it) and is expensive. Kinda leaves geo not cost effective when one has to go through all that.
[QUOTE=ga-hvac-tech;11796192]yes and no. you dont constantly have heated water running through the comparitively short wells with DX and they dont store heat (or lack of). So while the ground will heat up, its ok bc the superior heat transfer can deal with it. Its designed so the rate of heat dispersion (sp?) of the earth is equal or greater than the rate of input.
[QUOTE=ga-hvac-tech;11796372]again, sort of. the pumps usually do shut off between cycles but hot moves to cold...so the water temp is still evenly dispersed...
bigger field means a bigger pump which means more energy draw...
This is why no watersource mfr's put the pump inside the cabinet...it would hurt their EERs and COPs too much.
[QUOTE=Gross;11796412]THX 'Gross' (screen name) for the input, it is much appreciated.
I have some things I need to do today... may get back to you this evening.
Can you send along a PM with a few links I can read for more education? I think the mods would take them down from a public thread. THX!
GA
[QUOTE=ga-hvac-tech;11796032]JP...
I was talking to someone a week or so ago... they said something about the ground getting heat-soaked or cold soaked. What that means is; after years, the efficiency just goes down. I can understand this, makes good sense.
Any of the geo contractors know if wells get heat soaked?
I have never heard of heat/cold soaked before. I have some systems out that are 20+ yrs and had no problem. I even have a 3 ton system on a 2.5 ton loop that is working fine, it is also over 20 yrs old. In this area we do 200' wells, around 75' we hit some kind of water, may not be good enough for drinking but it still makes a good heat transfer when the end of a loop is hanging in water. On the newer systems we add an extra loop which doesn't add much cost but keeps loop temps more stable.
I too am looking at building a house in a few yrs with geo and solar mix so I find these threads very interesting.
I know DX geothermal exists and have been used and in theory should perform better. But because someone installed them in the 1970's and got away with it doesn't make them legal today. At least where I live they are not legal.
Even if they were legal, would you install thousands of feet of refrigerant pipe in a building when it is not accessible and you hope there never will be a leak? Why would you do that in the ground when in addition there is a chance to break the pipe when installing, assuming it is some rigid pipe. And who pays for thousands of pounds of refrigerant?
I'm not saying they are not a good idea nor hat they are not allowed anywhere. I'm just pointing out some issues they will introduce. and the fact that everybody (besides some you may know) uses water/glycol should tell that I'm not the only one sharing that concern.
again, youre ignorant to what youre talking about. I, as well as other members of this site, install them currently. I put in two last week. There isn't thousands of feet of pipe or thousands of pounds of refrigerant. Its more like 10-25 lbs, depending on the system. Youre passing judgement on something you obviously know nothing about. As far as breaking a pipe, who pays for the well pipe to be replaced when a hdpe pipe breaks?
A horizontal system is only a few deep in the ground. In winter it cools down quickly since no heat will travel to it from above. you will have large dT between summer/winter. If in winter you have 32°F water instead of 50°F water your heatpump works much harder using more energy and wearing more. You also can get below the HP rated temperature. In addition you need a lot of space as soon as you apply it to more than a home. It is cheaper than vertical well, but the fact that almost everyone bites the bullet and pays for vertical wells should tell you :)
We own one of the horizontal systems. Beside the engineers making many mistakes, the inherent disadvantages of horizontal made it so much worse.