I have a standing column geothermal system, in place since 2010. The well is used for both the heat pumps (4.5 tons) and domestic water supply. System is set up so that all water is pumped into a pressure tank, then through the heat pumps or into house. Return line after the heat pumps to well. Well is 465 feet deep, and has a rate of 2 gpm. While this seems low, I have never had an issue with water getting too cold, or too warm. I can and do bleed about 1 gpm, which is around 10%. I can bleed more, and have never had problems with running out of water, so I suspect the well is actually producing a lot more than 2 gpm. My pumping costs are high, and I suspect it is because the system does not take advantage of the syphoning effect on the return to the well because everything runs through the pressure tank. Is there a way to have a separate pump that essentially just circulates water to and fro the heatpumps (maybe one that is under the house), and let the in-ground pump service the domestic water supply? Thanks in advance for your help!
First question I have is what is your depth to water, the well is 465 feet but how much water is in it? A pump under the house would have to essentially lift the water by vacuum which is limited to about 30 feet, I suspect your depth to water is more than 30 feet. Also where are you located and what size well is it?
Depth to water is about 30 feet. Well is 6 inch diameter, 465 deep, pump placed at 445 feet. House is on a hill, probably another 10 feet above well. With production of well relatively low, I suspect the water depth fluctuates somewhat depending on usage, but I do not know for sure.
http://www.geoexchange.org/forum/threads/standing-column-pumping-energy.4849/ Give this thread a read. ChrisJ
Thanks! That thread looks like the info I need. Now if i can get my accountant training to manifest as its inner engineer, I'll be on the right track!
Turkeyboy: Good luck on your transformation. I have been trying to move my car and mechanical hands in line with my inner engineer. After 30 plus years in HVAC my retired brain keeps gathering information and know how, my hands protest. Let me know if I can help. Mark
Here is another thread from Green Building Talk, http://www.greenbuildingtalk.com/Forums/tabid/53/aff/13/aft/80320/afv/topic/Default.aspx Blake goes into some detail. Chris
