Improve bathroom exhaust

[savvygl]

Hello. First post, but I have referred this forum many times before.

I renovated my bathroom last year and had a handyman friend do a large portion of the work, including installing my new Broan exhaust fan. Recently (due to the problem I will get to in a moment) I was assessing the exhaust fan in the attic above and realized that he did not vent out of the attic. Uninsulated 3 inch flexible tubing is stretched to the soffit, but not vented through the soffit. I asked him about it and he said that in our climate (central South Carolina) venting out of the house is not necessary. I think otherwise and plan to have the bathroom exhaust vented through the roof once I figure out what to do about the fan unit. Plenty of room to work and a short run straight up and through the roof. No problems I can foresee there.

My biggest problem now is the fact that the exhaust fan hardly seems to move air. Steam accumulates in the room during a warm shower, condensation builds on the wall, and water drips from the fan grill. The exhaust fan in place is one of the less expensive 80 cfm Broan units I bought from a big box store. Maybe I got a bad unit or maybe the model is rather ineffective (I have read other negative reviews), but either way, I need to fix this situation. I will just consider the Broan unit currently in place a loss. I am curious what I can do to improve this situation without replacing the entire unit. I do not want to tear out the housing and deal with cutting the ceiling and installing a new unit (if I can avoid it). Could I simply replace the current motor with a motor with a higher cfm rating? Is an in line unit the way to go? This is the only bathroom in my bungalow. I am looking for the most cost-effect solution.

Thanks in advance for any feedback or advice.

[jadnashua]

First, figure the volume of the room (lxwxh) in feet to get the total CU FT. Then, see how many times/hour your fan will exchange the air. 8-10x exchanges an hour is not unheard of. Also, keep in mind that in order to push air out, some has to come in. In a really tight house, you won't get much out. Doing so would create a vacuum, which a small fan just can't do.

One system I really like, and have in my home, is a Solatube tubular skylight with the fan option www.solatube.com . It lets a huge amount of light into the room without the UV or heat of a typical window, and the fan is a decent size as well. It's been years, and I still reach for the light switch sometimes...

[savvygl]

Thanks for the reply, Jadnashua. This is a pretty small bathroom (approx. 8' x 6' with 8' ceilings) and an 80 cfm fan should easily remove steam. I don't think the unit I have is actually "living up" to it's claimed ventilation capacity. After some research I am leaning toward buying an inline retrofit kit such as this one from fantech http://www.bathroomfanexperts.com/pr...product=111111

That Solatube skylight system looks great and I will keep it in mind as a possibility in future projects, but for this project I am interested in a solution that will not require removing the fan housing or making any other holes in the ceiling.

Thanks again.

[jadnashua]

I put my Solatube in place of the previous fan...no new holes there in the ceiling, anyway.

[99k]

Several things:
First, I would use a 4" line because there is less pressure drop.
Second, make sure you have enough gap under the door to allow sufficient air flow while the door is closed.
Third, I don't know how old your system is but you need to clean the fan (I have a squirrel gage) yearly to remove dead skin(it's true) and lint.
Lastly, an inline fan by fantech is a much better choice if you are going through the trouble of changing it