Originally Posted by skizot
I think if you were moving the air across the coil that fast you see other problems.
You asked before about velocity's across the coil and the 300 to 400 number sounds OK ballpark, but that is not how the manufactures rate them. They do testing to an ARI standard that is making sure they maintain a minimum FPM that is a ratio from capacity to CFM. That kind of math makes my head hurt, so I stick to looking at the proper duct design and the units fan will move the air at the proper speed if I set it up right.
Do you have a slab coil? Or is it an N or a A? The shape matters if you want to do the math to estimate the velocity. I find it easier to just measure it myself.