David Cloutier
12-20-2013, 10:17 AM
While avoiding the debate over the risk/benefit/why-install-these-things-at-all...
A newly installed attic fan vibrates. The lateral deflection is minimal - think back massager, not a ceiling fan with one blade.
Short story: crappy fan or improper mounting?
Long story setup: 1,5500cfm attic fan with thermostat and humidistat. Manufacturer (AirVent, Inc model 53850) suggested use up to 2100sqft. (Attic is 1,500 sqft.). Stick framed roof with 1/2 in. OSB sheathing. Fan is installed about 2/3 of the way up a 28ft rafter. It's immediately alongside the rafter, also where a horizontal collar tie and a diagonal strut are nailed to the rafter.
Upside: lots of support
Downside: vibration radiates in all directions
The fan appears properly mounted from the outside and inside view. It was slid under the upper row of shingles and nailed into place. There is some deflection if I push on the fixture outward (from the inside), from what feels like flex in the metal flange. Viewed from the inside, the flex is about 1/4 inch gap between fan and shingles.
Are there tricks to better mounting, isolating the vibration, or simply R/R the unit? (yeah yeah, maybe just "R" and no "R/R") :)
A newly installed attic fan vibrates. The lateral deflection is minimal - think back massager, not a ceiling fan with one blade.
Short story: crappy fan or improper mounting?
Long story setup: 1,5500cfm attic fan with thermostat and humidistat. Manufacturer (AirVent, Inc model 53850) suggested use up to 2100sqft. (Attic is 1,500 sqft.). Stick framed roof with 1/2 in. OSB sheathing. Fan is installed about 2/3 of the way up a 28ft rafter. It's immediately alongside the rafter, also where a horizontal collar tie and a diagonal strut are nailed to the rafter.
Upside: lots of support
Downside: vibration radiates in all directions
The fan appears properly mounted from the outside and inside view. It was slid under the upper row of shingles and nailed into place. There is some deflection if I push on the fixture outward (from the inside), from what feels like flex in the metal flange. Viewed from the inside, the flex is about 1/4 inch gap between fan and shingles.
Are there tricks to better mounting, isolating the vibration, or simply R/R the unit? (yeah yeah, maybe just "R" and no "R/R") :)