How do I get and keep air out of my geothermal loop?
We have a “closed loop” geothermal heating and cooling system. 97 wells 300 ft. deep. 4 story building. 36 water source heat pumps. 72 electric water pumps. 219 ball valves.
There is no way at the high point (attic over 4 story) to release air and no easy way to add water to displace the air. The contractor keeps trying with their big pump and tank trailers to purge the system by driving the air bubbles out through the basement. No surprise to me, having observed the bubbles in my bathtub travelling upward, this approach keeps failing.
Our piping is very convoluted and there are many branches. I don’t see where anything with 219 brass ball valves and 76 electric water pumps could be considered a “closed loop” that won’t regularly need water in and air out. I suspect that they have designed it that way to cause dependency on their big tank and pump trailers to do any service work.
Seems to me, a pipe delivering city water through a couple check valves in the basement, and a high point air release valve (that lets a bit go whenever its paddle isn’t floating) would do the trick. Then changing out a pump, valve or heat exchanger would no longer require calling the guys with their giant operation to come from the big city to put a couple gallons back in. That and it would end the repeated failures which are most inconvenient. Is there a flaw in my logic? Has anyone had a similar problem? What is the solution here? Is chasing the air through 72 branches of piping, through little intricate heat exchanger coils, from the attic over the fourth floor and all the way down and out through the basement really the best way to eliminate trapped air? There are a lot of deareators on the market, is there one in particular I should be considering? Thank you all.