I just signed up after trying to read any and all articles I could on this topic but I still have a few questions. I purchased a property that the well had already been tested and proved it could provide enough water for an open loop geothermal system. I am trying to keep costs low and also doing this to avoid getting a new propane furnace, I just ordered a climate master TZ Tranquility 22 series 4 ton unit. There is also a small pond that I was going to run the discharge line to however I want to make sure I understand this correctly, since I live in Northern Indiana the discharge line needs to be buried below the frost line (roughly 4' or more) correct? Also when doing this it will mean the line will be below the water line of the pond do you put a check valve or anyting on this line? I think that is it I really just want to make sure the discharge line is run correctly. Thanks, Andy
Vacuum break backflow prevention should be considered. The potential exists (check valve failure) for siphoning pond water and whatever else is in there into your equipment, not to mention your aquifer. Your discharge temperatures should be well above freezing, 42.3f according to CM specs at min flow rate. When flowing you will actually be heating the ground and pond at times during the winter. You will still have to take measures to prevent freezing when you are not flowing. Mother Nature always wins in the end.
Thanks, I will add a check valve where the line comes through the basement wall. With the the line buried so deep I do not see how freezing could be an issue the line is buried 4-5 feet below ground.
The colder the weather, the more often you'll be flowing water, so less vulnerability to freezing. The one condition that would turn this reasoning upside down would be a restart after several days of dormancy in winter such as after vacation or long power failure. Every open loop design should be carefully evaluated as to pumping power. Done badly, excessive water pumping energy can eclipse energy and cost savings of geo systems.
