I'm still thinking of the electricity analogy here. Won't putting 2 HF in parallel increase flow and two in series keep the same flow but essentially act like a greater horsepower motor and withstand greater pressure?
Basically, series increases voltage and parallel increases current.
Also, as air isn't very compressible at these pressures, I think that the pipe cross sectional diameter will make a big difference as to whether two collectors will work together in an additive fashion.
I was planning on two HF 2HP collectors in parallel going through 6" pipe (presently flex, but hopefully rigid in the future.) I can't see how two 1550CFM DCs in parallel wouldn't produce more flow than one if it is going through non-restrictive piping. Maybe not through 2.5" or 4", but through 6" I think it should help dramatically.
Basically, series increases voltage and parallel increases current.
Also, as air isn't very compressible at these pressures, I think that the pipe cross sectional diameter will make a big difference as to whether two collectors will work together in an additive fashion.
I was planning on two HF 2HP collectors in parallel going through 6" pipe (presently flex, but hopefully rigid in the future.) I can't see how two 1550CFM DCs in parallel wouldn't produce more flow than one if it is going through non-restrictive piping. Maybe not through 2.5" or 4", but through 6" I think it should help dramatically.