I am struggling with replacing our 21 year old WF heat pumps and would appreciate some advice. We are thinking of using two WF System7 036 units, one for upstairs and one for downstairs in our 3,300 sq. ft. home. A variable speed one-pump flow center is anticipated for each unit. Question 1. Is there an advantage to connect the two loops and run them as a unit – in parallel, even though their lengths are quite dissimilar (as described below)? Is there a problem with leaving them separate? Question 2. Do I have enough loop to operate the two 036 heat pumps (nominally 3 Ton each)? I hope that System7 is real smart and can de-rate itself gracefully when the need arises. I am worried about low EWT for the shorter loop. Background Info: We drilled two 6” diameter wells in 1985 of 265 ft. and 390 ft. in depth to service a 2-Ton heat pump for upstairs and a 3-Ton heat pump for downstairs. The wells are 8 feet apart. The heat pumps are WF ATV028 and ATV034. They were installed in 1993 replacing the original 1985 WF Command-Aire models which had serious compressor problems. The loop piping is 1.5” cts. Polybutylene. Both loops and units are currently separate, not connected in any way to each other.