[rocketdoctor]

Im trying to install a fan in a laundry room thats in a lower room of my tri level home. The only way I can figure to run the duct is through a chase made for heater ducts. I was thinking of running a rigid 3" pipe up to the attick close to the ridge vents. This run would be about 12-15 ft. the fan is a 70 cfm fan and trying to figure if its powerful enough or do I need to get one more pwerfull. I couldn't find any limitations on the instructions or manufacturer's website.

 

[rocketdoctor]

I contacted Nutone with questions about fan distances and they gave me the following information

With 4" you can go 22' with a 80CFM fan and 23' with a 70 - every elbow you lose 4'
The HD 80nt is rated for wall or ceiling.

They said it was important to use 4" ducting even though the Fan itself has a 3 inch duct. ​