Does anyone have suggestions of how to better seal ceiling penetrations?
I have a house which was built in the 1960s, with some type of insulation which seems to have fine dust like fiberglass. Last summer I crawled around the attic and sealed all of the celing light fixtures, vent fans, and a couple holes which were drilled for wire drops for wall switches or outlets. I used caulk on a few light fixtures, trying to fill the perimeter gap and covering the small nail holes. I also sprayed foam around the fixtures, trying to cover at least a couple inches around the fixture electrical boxes. It made a significant difference in the dust inside the house, but this year it's begun again in the bathroom area. When the bath vent fan is run and all windows are closed, the insulation smell is strong. Also during the summer when the attic temperature increases, it's a strong smell of insulation dust.
I did put soffit vents in all over, but don't have a ridge cap or power vent. There are 8 passive attic vents which seems like it should be sufficient, but when the attic temperature increases, the insulation smell is strong outside due to the hot air escaping through the soffit vents. None of the vents are blocked, but the dust problem increased when I removed the whole house attic fan.