I bought a house that has a 3 ton geothermal heat pump configured with an open loop. I want to convert it to a closed loop. I was researching and asked some questions on here in 2015, with the intention of performing that work in 2016. Other responsibilities got in the way, and now I am back reviewing my notes along with threads from this forum and the questions I had asked. I hope to do the conversion in 2017. Back in 2015, I was thinking series horizontal loop with propylene glycol, I was corrected am now on to considering parallel horizontal loop with methanol. Also, early on I had found some used butt fusion equipment but that purchase did not work out, so now I am going to go with socket fusion. So the following questions regard flushing and purging: I knew that with butt fusion, the fused pipe seams are narrower than the internal diameter of the manufactured pipe. When PE pipe is socket fused, are there pockets inside the weld between the two pipe pieces that could trap air/dirt during the flushing/purging? Should flushing/purging be performed before or after adding the methanol? What sort of filter should be connected to the flush cart? I was thinking of a whole house filter from one of the big box retailers.
Usually a wire mesh is in the purge carts. You don't want to restrict the flow too much during purging. Normally you don't have to worry about pockets with socket fusion.
> "you don't have to worry about pockets with socket fusion" Do you mean, that if done right there are no pockets? > "Usually a wire mesh is in the purge carts" I was thinking of using a plastic trashcan. I saw a number of pool pumps have wire mesh strainers built in, is this similar or the same sort of thing? Thanks. What of the antifreeze (methanol), add before or after the flush/purge?
I have an inline filter plumbed in parallel on the purge cart. Add antifreeze during the purging process unless you have some nasty stuff in your pipes. Butt or socket (or electrofusion) doesn't really matter. Don't overheat if you're worried about restrictions.
My heat pump is in the basement, and the loop will be run along the underside of the main floor joists over to the wall and out. Will the flush cart need to be higher, like ground level or on the main floor some how? or will the pressure of the pump, and the air purging prevent the water backflowing and overflowing into the flush cart...
No, flush cart in the basement is fine. The pressure of the pump is strong enough to prevent back flowing,
