Average Reviews:
(More customer reviews)Broan 472 Backdraft Damper/Reducer
This 10" to 8" duct reducer comes with spring-loaded dual-dampers on the 8" end. I installed it on top of a Broan 10" Vertical Discharge Fan, and was disappointed in the fan's performance. When I held a hand near the fan's intake in the kitchen ceiling, some air was actually being blown down, when it was supposed to be sucked upward. Before completing connection of the damper/reducer to a roof cap via duct-work, I went into the attic to check it out from the top. Some air came through, but the problem was obvious -- the dampers on the Broan 472 were only going up about 25 degrees. When I lifted the dampers all the way up by hand, air output soared.
A spring forces the dampers closed when the fan is off. Holding the damper down that way reduces rattling in high-winds and keeps the outside air from coming in, but it also cripples a small fan's performance. To fix this, I removed the spring with wire cutters, and installed a screw at the top of the reducer on each side, at the 85 degree point, to stop the dampers from going past mid-way. With this screw-stop approach and no spring, gravity keeps the dampers down when the fan is off, and the fan's output is fine with a small fan, since the air doesn't have to push against a too-strong spring.
The spring-loaded damper approach should work OK as it comes from the factory if the unit is installed horizontally; but it doesn't work acceptably in the vertical position (with a small fan). Luckily, there's an easy fix.
The metal-work aspect of this product is excellent.
Click Here to see more reviews about: Broan-NuTone 472 Transition
Broan-NuTone 472 Transition Since their beginning in 1932, Broan has pioneered many of the product innovations now established as standards of the industry. Today, Broan carries on the commitment to provide the finest products in the industry.Broan-NuTone 472 TransitionFeatures:; Fan Accessories, Ducts, Transitions, Elbows; 10" to 8" Reducer-damper, use with Model 504 (includes damper); Converts 10" round duct to 8" round duct; Includes damper.
Click here for more information about Broan-NuTone 472 Transition
