I've just upgraded the pathetic nuisance of a bath fan the house came with....there is now a shiny Nutone Quiettest 110 cfm fan in there. Also upgraded the crappy plastic flex hose to 4" aluminum flex hose and installed the hose insulation jacket on it. Couple of Q's on this now...
- the opening around the fan box - of course the original drywall ceiling opening was cut jagged and imprecise, and we had to do some more simple tweaking on the opening to get the new box in there. this has left some gaps around it for air to pass up through. What is the proper method to sealing this? I'm assuming I should wrap the box in vapour barrier, and then pack insulation around it? should I bother with vapour barrier at all and just just stuff the gaps with insulation?
- the roof vent - of course the vent on the roof itself is of 3" design, and the new fan is 4"!! needless to say to get things going this time of year I picked up a 3" to 4" reducer and connected it as-is. do you recommend having a roofer upgrade to a better quality 4" vent? am I losing much by adapting down like this? is it something to even worry about??
otherwise the fan seems to be VERY effective. I can no longer leave the bathroom window open (its in the shower area) with the fan running because it draws so much air with the room closed that there is literally a cold wind being sucked in!! having the hottest shower I could (to create as much steam as possible), the mirror never got an ounce of moisture on it. and within 1 or 2 minutes of the shower ending, the room is completely clear.
needless to say I'm happy, I just wanna be sure i finish up the job appropriately.
b