On a recent bath remodel I did, the bath fan was put in using 4" flex duct. About a 20 foot run of it. The fan that was installed was a NuTone ILF250. After getting a call about moisture in the bathroom I came over to see what was up. I found some of the connections were crappy so I re did them with clamps and the foil tape. But I still wasn't get much air flow.
I called the sparky, he said he would install a new fan and return the old as defective.
When I got home I pulled up the spec sheets and see NuTone asks for a 6" duct, not 4". The bath is 1000 cu/ft....so a 250 cfm fan should be overkill? Is the 4" duct restricting the flow that much?
Thoughts Comments?
I also should add that there are dual inlets in the bathroom, so its a dual 4" line for about half the run, then it y's into a single 4" for the other half.
I called the sparky, he said he would install a new fan and return the old as defective.
When I got home I pulled up the spec sheets and see NuTone asks for a 6" duct, not 4". The bath is 1000 cu/ft....so a 250 cfm fan should be overkill? Is the 4" duct restricting the flow that much?
Thoughts Comments?
I also should add that there are dual inlets in the bathroom, so its a dual 4" line for about half the run, then it y's into a single 4" for the other half.
