Fiberglass Dust Moving Through Ducts
I moved into my energy efficient house about two months ago. Recently, I started wondering about fiberglass dust.
We have a one-floor home with an attic. The attic is unvented and considered part of the conditioned space. We have closed cell spray foam insulation on the ceiling, then below that, there is blown-in insulation held up by some kind of fabric.
Our Fujitsu indoor unit and our ERV are located in the attic. When the HVAC guy installed the Fujitsu, he disturbed the insulation, which I didn’t really clock at the time. But he was complaining about how itchy he was.
When my husband and I went up there to start storing stuff, we noticed the floor (just OSB) was really dusty, and there were pieces of insulation on the floor and the tops of the mechanical equipment.
Also, the fabric has penetrations where the blower hose went in. They covered those with some kind of clear tape, but it fell off. So my husband went up there and tried to cover them with duct tape. He also tried to vacuum up the dust twice with the shop vac. The duct tape fell off, too. And it’s still dusty on the floor (and we have recently learned that may have been a horrible idea and that you need a vacuum with a HEPA filter, or else you make the problem worse . . .)
Anyway, the last time I went up there to pick up the duct tape, I started wondering if the dust could get down to the living space. Then I noticed a couple pieces of insulation were stuck in the grille in our office and the grille in the mudroom. I have no idea how long they were there.
We have been running the “fan” setting on the Fujitsu just to circulate air. We have a supply vent in the attic (but not a return), and we found that running the “fan” setting keeps the humidity in the attic very close to the living space (we live in zone 5 and we have been trying to be very careful about paying attention to humidity). The temp has always been the same or a few degrees lower than the living space.
The house’s temp and humidity has been comfortable with just the ERV, so there has been no reason to use the Fujitsu lately (there is no ERV supply/return in the attic, by the way).
So, a few questions:
– Do I have reason to be worried about fiberglass dust? I have no idea if this set up (blown insulation, heat pump in attic) is common or not.
– Does the fan on the Fujitsu bring air from the environment into the system? Or is the system completely closed? I am afraid that the supply vent is disturbing dust and it’s getting sucked into the HVAC system via the fan. The manual for our unit does not address this, and I can’t find it explicitly addressed online.
– Should my contractor have done something more with this to protect the home from fiberglass dust? For example, is the insulation fabric enough to keep the dust from continuously settling down to the attic floor? Should they have covered the holes / the entire thing with something? Should they have cleaned up the space before we moved in?
I’m having trouble finding anything online because my understanding is most attics are completely sealed off from the living space, so coming into contact with the fiberglass isn’t likely. Here, however, the spaces seem more “related,” and I’m afraid the supply vent is doing something. It also seems somewhat uncommon to have your HVAC in the attic. (We don’t have a basement.)
Plus, we intended to store stuff up there. It seems like at the very least, the attic is contaminated and will be until it is abated properly. It seems like every time we open the attic stairs, we could bring dust down into the house.
I already have a line out to the HVAC person, but he is difficult to get a hold of, and for various reasons, I would like other opinions.
Also, I’m feeling kind of stupid that I didn’t think about this earlier, and I’m afraid that we’ve been breathing in harmful air for two months.
Absolutely no one on our team seemed concerned with the set up, including the third-party energy consultants that checked the duct work, airtightness, etc. for our ZERH certification. Or if they did, no one said anything to me.
But there have been a few things that have come up lately that have shook my faith, and now I can’t tell if I’m being reasonable or unreasonable in my concern.
Any insight is helpful. Sorry for the long post.
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