Question about exhaust fans (kitchen and bath)


#1

I’ve got a new roof going on in a couple of weeks. Also have all new vent baffles, soffit (invisivent), and some blown-in cellulose added in attic.

Here is my question.

Right now, I have a range hood exhaust fan and a bathroom exhaust fan installed that dump directly into the attic. The setup my roofer is going with is continuous invisivent soffit with a powervent fan controlled by temp/humidity. With such a setup, is it really necessary for me to cut into my beautiful new soffits and to install a vent termination for these exhaust fans or can I keep dumping them in the attic? It seems like the powervent, will maintain a proper temp/hum up there anyways?

Any thoughts?


#2

absolutely do not vent them direct into the attic. i would vent them straight through the roof. they make vents specific for those. i probably wouldnt vent them through the soffitt, as it is an intake vent and if it is functioning properly it will just suck the exhaust back into the attic.


#3

Good advice. Thank you. After some thoughtful analysis, I realized that when the powervent kicked on it would just create three giant vacuums down into my house!! AAAHHHH! I also thought about the exhaust being sucked right back through the soffit. Another good point. I think I will go out the roof.


#4

make sure you use the proper flashing kit for the specific vent.


#5

Hi,

Yes, vent them through the roof.

They are called a 4" roof vent with flapper.


#6

There are 2 different sizes made and also go by the name, “Damper Vent”. Broan makes the ones we use here and they are carried by the local Menards in the heating supply section.

Smaller one for the bathroom exhaust damper vent.

Larger one for the range exhaust damper vent.

Use metal piping, not the plastic flexible springy plastic tubing for the range exhaust as these can be a porential fire hasard with expelled grease.

The bathroom vent comes with or without a plastic tube kit. Get that one with the plastic tubing to exhaust the humidity from the bathroom.

All of the other previous advice is right on the money.

Ed


#7

Hello,
If your house has a gable end then you could run the vents out the gable. This helps alleviate any ice build up on the roof if you use the vents often.(jmo)

Keith


#8

Wow, this is a great forum. Thanks for all the advice. Unfortunately, I have a hipped roof, so no gable area. I will take the advice given here and go through the roof. Problem is I live in Michigan and we get a lot of snow here. I need a vent kit that gets me at least 12" up out the roof and all I can find online are ones that sit almost flush with the roof. My plan is to install it before the roof goes on in a couple of weeks. That was when the roofer comes they can just reseal, flash, and roof around. Better for them and me that way! Any northern climate roofers here, what type of termination kit would you recommend that gets me above snow level and isn’t too ugly?


#9

Hi again Ed. Thanks for the info. I’m confused on this suggestion. What exactly is the plastic tubing? Does that mean the plastic flexible duct? or something else…


#10

the ones you are looking at are fine. dont worry about the snow. dont install it too close to the edge of the roof. make sure your roofer doesnt knock the flex duct off the flashing kit.


#11

yes


#12

The plastic tube that Ed is referring to is like a dryer exhaust tube.

I am in the Traverse city area, GTP is in the Detroit area, I have friends in the Muskegon\Grand Rapids area.
Where are you?

I don’t know of any bathroom vent flashing that sits high enough above the roof to not get covered by snow in Michigan.
If that is what you really want it can be done with pvc pipe in such a way as to look exactly like a regular vent pipe you will find on all roofs.
Not really needed IMO.


#13

[quote="-Axiom-"]The plastic tube that Ed is referring to is like a dryer exhaust tube.

I am in the Traverse city area, GTP is in the Detroit area, I have friends in the Muskegon\Grand Rapids area.
Where are you?

I don’t know of any bathroom vent flashing that sits high enough above the roof to not get covered by snow in Michigan.
If that is what you really want it can be done with pvc pipe in such a way as to look exactly like a regular vent pipe you will find on all roofs.
Not really needed IMO.[/quote]

I am in Durand. Right smack between Flint and Lansing on I-69. So you would say its not necessary to get vent about snowlevel on a roof? I’ve been in the heating and cooling trade as an installer/technician for about seven years so I know a little bit about ventilation and ducting stuff. But totally new to owning a home and just want to make sure this is done right. I know in furnace venting (high efficiency) we use PVC out the side wall of the home and have to make sure it is vented above snow level…thought maybe that same principle would apply to fart fans. If not than I will just go with a standard roof vent kit.


#14

Go with the standard Broan roof kit mounted flush to the roof. I am in the NW suburbs of Chicago and even though you guys get lake affect snow from both sides, we still get our share here too with no realized problems.

Remember that the heat being expelled from the vent will melt the surrounding snow.

Mount it flush to the roof. It is not gas like from a high efficiency furnace that yoiu were referring to.

If you do not have a roofing contractor set in stone yet, I would highly recommend both GTP and Axiom for their proven knowledge on proper techniques.

They are calling for snow here Wednesday night through Friday. Get your tarps purchased and ready.

Ed


#15

Thanks for the compliment Ed but he is a bit far away for me.
Besides, he is a HVAC guy, he knows how to put in one of these.


#16

[quote=“furnaceguy”]

My plan is to install it before the roof goes on in a couple of weeks.

That was when the roofer comes they can just reseal, flash, and roof around.

Better for them and me that way! Any northern climate roofers here, what type of termination kit would you recommend that gets me above snow level and isn’t too ugly?[/quote]

Axiom,

He is getting the whole roof done in a couple of weeks, so it is not just an install of a bathroom vent job.

Ed


#17

I forgot about that.


#18

You guys are super helpful and a friendly bunch too. I appreciate the offers, but we found a really great (professional, quality, good service) roofing contractor in our area that we are happy to go with. They were the most expensive out of five bids, but I don’t care about price, I want a job done right and I want good service.

Don’t you wish all customers felt that way? I know I do!!! LOL