I've got a small half bathroom located next to my kitchen, and it's always been pretty cold, especially since it sits on a concrete slab with no basement underneath. Recently, I had a ceiling fan installed for ventilation, but now the bathroom is even colder! I measured the temperature, and while my thermostat is set at 68°F, the bathroom is only 55°F on a chilly day.
The issue seems to be that the fan is letting in cold air. I can feel a constant draft when I put my hand near it. Above the ceiling, there's an attic crawl space, and the fan is right next to the soffit. Although there's some blown-in insulation around, it doesn't seem to adequately cover the fan itself.
The fan is equipped with a damper and vents through a flex duct to the soffit, but it feels like cold air is seeping in from around the fan and housing instead of through the duct. I'm wondering if I can seal it up to keep the cold air out? It's a cramped space in the attic, making it tough to work there.
Is it feasible to caulk every crack? Would insulating the fan entirely help? Or is it pointless given its proximity to the soffit and cold air? Any advice would be much appreciated!
2 Answers
It's not ideal for that fan to vent through the soffit. You should ensure that the fan is properly sealed at the entry point to the bathroom. Check if the damper is working, and make sure that all seams are taped up. If there's no cap on your exterior vent, that might indicate there's no damper at all, which would allow for cold air influx.
You might want to consider swapping your fan for a fan/heater combo that has its own thermostat. Also, it's a good idea to apply some foil tape to any cracks or openings leading into the attic. Make sure the damper is functioning properly too, as that could be letting cold air in.
I tried using foil tape, but it didn’t seem to help much. I could cover the opening completely except for the fan, though. I'll check the damper again, but it feels like the cold air is coming from every direction! That fan/heater combo does sound interesting, but I worry that it would just end up running constantly if I don't stop the cold air.
There is a damper attached to the fan itself that came with it. Why is it not okay to vent to the soffit? I've re-taped every seam I could find, so I’ll see if that does the trick.