I have two different capacity centrifugal ID fans I wish to combine in parallel. They pull air through the same duct and exhaust through the same stack.
What is the pressure at the inlet and outlet of the fans? Since they are different capacity fans they should generate different pressure but since they are attached to the same duct the pressure in the duct will be same, i.e. the pressure at inlet of both fans should be same. Same is the case with outlet , since they are attached to the same stack they should have same outlet pressure.

How does the parallel combination in this case work?