Thanks for the info. I think when I tested things my heat exchanger water input temp was 60F and output was 70F. Ambient was 81F and humid (didn't record humidity unfortunately). With this, I was getting condensation on my crude setup. Cooling capacity was pretty low at ~3500 BTU though.

Here is a direct link to the testing post:
http://ecorenovator.org/forum/geothe...html#post14998

Cbearden

The storage tank should be within the house. Any heat losss from the tank would contribute to the space heating. Space to put it may be a problem. But I'm skeptical to you actually needing a buffer tank the concrete floor is a huge buffer in itself. But if you must I have an idea for you. Use a large dia. ABS drain pipe with endcaps between your second floor, floor joist. You could install as many as you like and wrap them with insulation. Be sure to pressure test. This way any incidental heat loss is lost to the inside of your home.

I think we should move this to one of the other threads like floor heat.

Randen

well, I was hoping to use the buffer tank for both heating (during the winter) and cooling (during the summer) capacities later on, after I get my gshp and loops installed in the ground. I don't think I'm going to have room to put in larger pipes in-between our floors like that. right now it looks like my only affordable options are to put this water storage tank in my shop underground, and pipe the water to my house 75-foot away.
I'll do my best at insulating the pipe. But this may be the most affordable options for me. I had originally planned on putting the water tank in the garage. But it seems less expensive to build underground, plus that'll leave more room in the garage for other things.

I will have room to put in plain 1/2" pex (not stapled up) in-between my floors for possible cooling. But at this point, I'm questioning how effective this will be for the additional cost of PEX loops. I DO plan on trying to find a way to switch my system over during the summer and use my pex in my floor to circulate cool water, even though it's not in the ceiling.

I'd have to check on this more, but lets just say hypothetically that I would have room in-between my floors for a large-diameter pipe. I could probably put in 3 or 4 of these cheaper than I could PEX all over. And then I could use these to help cooling during the summer by circulating water through them, instead of staple up PEX?
I'm not trying to cool the entire 2nd floor. more like, just help remove some of the heat that will rise up from the 1st floor, in-between the floors.
thoughts?

I am certainly no expert, but here is what I know. The temperature differential will be low with just cold water, especially if you are avoiding condensation. Therefore you need more surface area to get the same amount of cooling. This is kind of the same thing that the guys are doing with low heat (like GSHP and solar) heated floors. I don't think putting tubing into joist cavities is going to do very much cooling. I think you'd be much better off with a radiator and fan, or maybe a cooled wall for the convection benefits.