More adventures in MH repairs! Bath fan

[ponch37300]

We have been doing a bunch of upgrades in the past few months. We have paid off our home and have been using the extra money to make some repairs and upgrades including new deck stairs, new carpet, closet remodel, kitchen sink and faucet, range hood, couple ceiling fans, and lots of other stuff like fixing outlets and releveling and many other little things.

So today's adventure, I like to call any repair in a MH an adventure because you never know what suprises you will run into and you are sure to run into at least a few speed bumps whenever working on these homes! We have a 2000 model and it's actually built pretty good for a MH but being a MH it always throws a few curve balls. Our bathroom fans we those little round 50 CFM piles of junk that I've probably had times were my body gets rid of more air than those fans. So the other day out shopping at Menards we decided we might as well get a new fan and picked out a nice broan 110CFM ultra quiet light/fan combo. I decided to put it in this afternoon.

I ripped out the old one and saw we had blow in insulation which is always fun when you are working under that! The broan fans have a kind of stupid design, on the side that screws to the truss they have a flange on each side that sticks out over an inch. So it doesn't just slide up in the hole, you can't even put it in at an angle. You have to cut the hole about a half inch or so bigger than the fan box. The electrical was there and was the easiest part. The vent was 3" so I had to use an adaptor but not a big deal their either, some duct tape and zip ties and all was good there. I put some batt insulation up above the blow in to cover the hole where the blow in fell out, not a perfect solution but better than nothing and about the best you can do from below reaching threw a little hole. Got the fan wired and vent on and then put in place and zipped a few screws threw the metal housing into the truss and finished putting it all together.

Turned it on and it was louder than what it should have been. I'm pretty sure that this is because I reduced the 4" output to fit the 3" vent, I'm thinking the 3" vent is to small for the 110CFM fan and creating some turbulance in the air. Not thrilled about it and don't think it's pulling as much air out as it should but don't think there is too much I can do about it without a bunch of messy work trying to run a new 4" vent line. Thinking about doing a new roof in the next couple years so might do it at that time. The extra light is great because all we had was the cheap medicine cabinet light bar that didn't do much. I think I'm going to pick up some low expansion great stuff to seal up the gap around the fan housing just so the fan can't suck any of the blow in insulation.

All in all not to bad but like usually had some speed bumps where an attic access would have allowed me to run a new 4" line and also put the fan in from above instead of having to cut a bigger hole and fanagle the fan into place. But the cover covers the hole.

[bobfather99]

General armchair guide on fans, if you put a piece of paper or tissue up on the fan cover and it sticks to it while running, the fan moves enough air out to cover the square footage of the bathroom. If not, upgrade to a fan that has more cfm.

[ponch37300]

Yep our old ones didn't suck anything. The new one you can stick a few sheets of TP on it and they stay. But I think the 3" vent isn't allowing the fan to pull the 110CFM that it is supposed to. In one corner of the fan it even blows a little bit back into the bathroom which I think means the fan is sucking and trying to push 110CFM out but with the restriction of the 3" vent line it's pushing a little air back into the bathroom. The mirror doesn't fog up like before so it was an upgrade. I think that when I redo the roof sometime in the next few years I will cut out some sheating by the vent and run a new 4" vent line and it will be able to push what it's supposed to. This way I can go from above and be able to replace the insulation. I think if I tried to run a new 4" line only using the fan housing hole it would be a huge mess with no way to replace all the insulation that would fall out.

[bobfather99]

Should work just fine until you get the bigger vent line installed, the main thing is to vent the moisture out, which it sounds like youve improved greatly.