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Old 02-10-22, 03:01 PM   #10
jeff5may
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Been busy lately with life and such...

Good job, man! Haven't had time to read your pdf yet. Couple of answers to your questions, though.

Yes, the whooshing noise is normal for a cap tube system. It means you have refrigerant mass flow.

Regarding superheat: it's not a bad thing. You have to have at least a little bit of margin to make sure that the compressor is not ingesting any liquid. Propane has high heat capacity compared to most other refrigerants, so it actually helps your approach temperatures in the heat exchanger to have extra. 10 to 20 deg F isn't too much for a cap tube system.

For trenched ground loops using poly pipe, the goals are 5 watts per meter degC for 3/4 (19mm) pipe and 10 watts per meter degC for 1 inch (25mm) pipe. These goals are beatable nearly everywhere if the balance of the heat pump system is operating correctly. Just like the statement "everything worth insulating is worth super insulating", every ground loop worth sizing and installing is worth oversizing and installing.

Last edited by jeff5may; 02-10-22 at 04:06 PM.. Reason: Information
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