[randen]

The Master Plan wrote:

This last year just running the loop with nothing hooked to it the high was 58F the low was 38F. I am going to monitor it again this year.

Just from practical experience I would see this loop temp (38 F) after 3 months of cold weather and I would start to notice the GSHP running extra long to keep a comfortable room temp. The heating season would start out with a loop temp of 58 Deg F and seem to stablize at about 45 Deg F. for most of the season.

During the summer I will start "charging" the ground with heat from whatever source I can....solar, ambient air,bon fires etc. lol Even if I installed a reversing valve and used it as a A/C during the summer I could add heat to the loop. How much I wonder and how long would it take? I read somewhere they are doing this in Canada.

IMHO Try the GSHP out without thinking of charging the ground. The lost efficiencies in heating the ground and then try to recover that same heat would in all likelyhood result in a net loss. If you come up short during the heating season, install the extra tubing you had mentioned you have room for. That place in Canada you maybe referring to is Drakes Landing it is a housing community that stores solar heat in a deep and large underground area with wells and inturn during the winter recover the same heat. They don`t use GSHP as the temps are stored and recovered high enough (145 Deg F) to use directly for space heating. You can see their site on the web. They have a nice active display on the current conditions of the system. Temp of the bore hole, outside temp, and if they are collecting any solar heat to be stored, real time.

Why wouldn't the high rise use the heat pump during the summer and thaw out the ground or at least add heat to it?

I believed this was the case, they could pump in some heat during the airconditioning season. However, not enough air-conditioning as the amount of heat ejected into the loop thawed the ground around the tubing and the rest remained frozen. As the air-conditioning season ended and the heating season began that heat immediately next to the tube was used up quickly and refroze.

I think this is going to be a big learning experience and a fun project to tackle. Yes it can be fun. It is very satifying to make your own system from junk and gathered pieces that can perform well. There is a wealth of information here from people who have had success. AC_hacker has un-earthed and tested the black magic and math that make these vapour compression machines work and the low-temp heating methods that work so well. Not to mention Vlad who has done the same with heated floors and drilling vertical loops for the ultimate performance. Fun to be had.

Randen