Persistant smell in house dense packed with cellulose
We insulated both attic and walls with cellulose. One bedroom that has the attic staircase in the closet develops an odor that the customer says “smells like the day you were installing it”. When you open the closet there is no smell, so it is not coming down attic staircase. Customer has bought covers for air conditioning ducts that are in the ceiling. Room is heated by a boiler with recessed hydronic registers under windows. Pipes run through the exterior walls that are now dense packed. Shoe molding is missing from baseboard. Only thing I can think of is that heating pipes in walls now sitting in dense pack cellulose are producing some odor. We are going to caulk baseboards, remove register cover, seal around sheetmetal, install receptacle gaskets and hope for the best. Will odor go away with time? Is boiler set to high?
Help!
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Does it smell like newspaper, or does it smell like the cat peed in there last week?
The latter would be an indication of sulfated fire retardents somehow getting wet, which is a potential problem. If it was a damp sprayed or "borate only" dry-blown material it wouldn't have nearly the pungency of sulfated fire retardents, wet OR dry.
If it's wetting (and I'm not saying it is) the wetting could be roof or wall leaks, plumbing leaks, or condensation (if the AC ducts are somehow leaking and quite cold.
If the water temps on the hydronic plumbing is over 140F it could be slowly cooking out some of the volatile components of the newsprint & ink causing a noticeable smell. This would normally dissipate by the end of the heating season. Below 120F the outgassing would probably be too low for most humans to detect. (Do you notice newspapers emitting a slight odor when it's been sitting in the sun by a window? )
If the water temps in the plumbing are over 180F the cellulose itself can be breaking down. If the heating system was able to keep up with the heat load before dense packing, air sealing, & insulating, you should be able to safely back off on the high-limit for the boiler, keeping it at 160F or lower and still keep the house warm. If it's an oil boiler you don't want the low-limit to be below 140F though, since chronically running it lower than that will damage the heat exchangers on an oil boiler due to corrosive exhaust condensing inside the boiler. (With gas-fired cast-iron 130F is safe.)
Did the smell go away? Getting ready to insulate with greenfiber’s borate cellulose and the bags don’t smell good at all. May rethink this. Thanks
I know it's an old thread, but I wanted to share my experience. I used GreenFiber 765LD to insulate vented attic. It's been about a year since then and even though I don't detect any smell inside the house it still smells outside near the house especially on the days with mild wind. It's not too bad, but kind of annoying. If I had to do it again, I probably would pick a different product/method for insulating attic. Just my $0.02.