Air Duct Cleaners

*HVAC* Is it necessary to have space between the air ducts and Allstyle plenum coil?

Mike asked: I think my coils were installed wrong a few years ago and ever since then I’ve been having a problem with low air pressure coming from all of the return vents. I noticed that the ducts are connected right up against the coils with no space in between, and two of the ducts [...]