This is a post-weatherization photo of how a contractor in a local low income weatherization program boxed a bathroom fan. That's the fan buried in cellulose with a piece of tin laying loose on top of it. The fan is in complete contact with the insulation which, in my opinion, could lead to a fire and there certainly is no air sealing going on. Seriously shameful.

Tags: attic, bad, boxing, fan, income, low, program, tin, weatherization, work

Views: 436


Replies to This Discussion

If it's just a bath fan, what's the fire risk? Do the manufacturer's instructions call for clearance to combustibles?

I'm with David in that question. Not sure it's a fire risk, but it is a leaky component adjacent to a high humidity source. Does not look air sealed.

Addressing this as you would a can light before adding cellulose is how I've addressed this (box, 2 part all seams)

I think some may simply seal penetrations and seams in the box, which might be acceptable and does not appear to have been done either.

Wonder what local requirements are or how others handle this.

Ted, I was taught to box with 5/8" fire-rated drywall with a 3" clearance from any heat source. Once the box is fit into place it is foamed around the base. I tape my seams inside and out with approved foil tape. Some of the programs feel drywall is a mold risk, so they require boxing in metal stove pipe with a cap.

That looks like a regular bath vent not one of those heat lamp / vent combos.

If you have a heat lamp combo in there that might be a good precaution (check with the manufacturer) but for the rest there is not enough heat generated to cause an issue.

The big issue are recessed lights where you have a regular or CFL bulb pushing out 200+ degree heat inside the fixture itself

I will use a combination of tape, caulk & even foam around the outside of it - I never really touch the inside as that can screw with the UL labeling & besides that they are nearly impossible to get them clean enough for anything to stick long term

I tape the joints in the box with foil tape before I install the fan, then go in the attic after the drywall is in and foam the fan/drywall joint after the duct is attached and taped. I don't know how worthwhile it is, since a lot of air leakage tends to be inside the duct, in either/both directions, but if I can seal something, I do it.


Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

SmithWatson commented on SmithWatson's blog post Top 6 Energy Efficient Brands for Gas Furnace and Boiler
"Thank you for your valuable comment Gary.Yes, the product AFUE rating and other numbers are from…"
6 hours ago
Eric Kjelshus replied to Barbara Smith's discussion Eliminating Standing Pilot Light Furnaces
"Biggest pro is to keep the clay or brick or high mass chimney warm  with the 4-8" flame.…"
13 hours ago
Profile IconScott Bloedorn, Matt Macfadden, Lauren Asplen and 1 more joined Home Energy Pros
17 hours ago
Tim Wulling joined David Eggleton's group

1000 Home Challenge

Linda Wigington distinguished between deep retrofits & deep energy reductions, thus expanding…See More
19 hours ago
Gabrielle Rossetti's event was featured

Online Course: ASHRAE 62.2 Ventilation for Single-Family Dwellings at Online - At Your Own Pace

October 15, 2015 at 6pm to November 27, 2015 at 7pm
20 hours ago
Tom White posted videos
21 hours ago
Diane Chojnowski replied to Diane Chojnowski's discussion Solar Decathlon 2015
"Great photos Steven! Thanks for sharing."
22 hours ago
Steven Lefler replied to Diane Chojnowski's discussion Solar Decathlon 2015
22 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service