Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-19-2010, 02:03 PM   #1
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


I want to install bathroom vents in my parents' upstairs bathrooms, since they don't have any and have mold issues.

The preferred area to have the vent exit the house is on the side, but the bathroom is dead center. It would be about a 30-foot run of duct. Is this ok? It's a small bathroom, about 6x12. I was thinking of using a 100CFM fan.

Also, since this attic is not finished, I take it I should be using special ductwork to keep it from freezing? Or do I just wrap metal 4" duct with fiberglass?

Thanks.

__________________
Andrew

secutanudu is offline   Reply With Quote
Old 01-19-2010, 08:48 PM   #2
Member
 
Join Date: Jan 2010
Location: Ozarks, Missouri
Posts: 67
Rewards Points: 75
Default

Installing a new bathrom vent fan


You would want to insulate the duct to prevent condensation inside the duct running back into the house. I've used the flexible insulated duct in my attic, but it was a short run (10').

30' seems like a long run. Can you not go straight up through the roof? I've never done it, but a recent episode of 'This Old House' demonstrated installing a fan vent in a shingle roof. He made it look easy. You might check their web site and see if the info is on line.

My other advise is the get the quietest fan possible. It will last a lot longer than the cheap builder-grade fans, and the family will use it. It will be significantly more expensive, but worth it.

Rick


Last edited by houseinthewoods; 01-19-2010 at 08:51 PM.
houseinthewoods is offline   Reply With Quote
Old 01-19-2010, 08:54 PM   #3
Member
 
jlhaslip's Avatar
 
Join Date: Dec 2009
Location: Canadian Rockies
Posts: 1,280
Rewards Points: 500
Default

Installing a new bathrom vent fan


Albany New York gets a fair bunch of snow, so I would go out the gable end and not bother the roof.
jlhaslip is offline   Reply With Quote
Old 01-19-2010, 10:01 PM   #4
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


I may be able to put a 4" hole in the soffit. It's not a very deep eave, so if it is not big enough, the only option is the gable, which is the 30' distance (i agree, do not want to put a hole in the roof). I want to get a quiet fan, but if the run is, in fact, 30 feet....how can I ensure the air will move all the way to the vent? Would I need another fan in the attic to help pull the air?
__________________
Andrew


Last edited by secutanudu; 01-19-2010 at 10:05 PM.
secutanudu is offline   Reply With Quote
Old 01-19-2010, 10:23 PM   #5
Member
 
Join Date: Oct 2009
Location: Freeport, ME USA
Posts: 120
Rewards Points: 75
Default

Installing a new bathrom vent fan


I personally would install a fan that is a higher cfm than you have figured. It will exhaust a greater volume quicker.
meboatermike is offline   Reply With Quote
Old 01-23-2010, 09:14 AM   #6
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


I will get the most CFM that I can stand, noise-wise. Is venting a bath fan through a soffit OK? Will moisture make its way back into the rest of the soffit vent into the attic?

Would it help or hurt things, if I go with a soffit vent, to tape over the soffit vent for a foot or two on either side of the new vent to prevent moisture from finding its way back in?
__________________
Andrew

secutanudu is offline   Reply With Quote
Old 01-23-2010, 09:40 AM   #7
Member
 
Join Date: Jan 2009
Posts: 489
Rewards Points: 250
Default

Installing a new bathrom vent fan


http://www.panasonic.com/consumer_el...oseyourfan.asp

Never ever vent through a soffit. The moisture will enter back into the attic causing mold and mildew. The shorter the duct the better and use insulated ducting. The noise rates are in sones. Look for a fan with the lowest sones if you want a quiet fan. Panasonic are THE best all around fan, no ifs, ands, or buts about it. Roof would be a better option than running 30'. If you have snow issues, run the ducting up toward the top of the roof. If you do decide to vent through a gable, make sure you don't have sags and allow slope in case of moisture buildup.
__________________
Josh Jaros Remodeling in The Woodlands, Texas www.jarosbros.com
jaros bros. is offline   Reply With Quote
Old 01-23-2010, 10:48 AM   #8
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


Ok, so no-go on soffit vent.

What about using an inline fan up in the attic somewhere, maybe in tandem with a bathroom fan to account for the long range?
http://www2.panasonic.com/consumer-e...00000000005702

Or maybe just a really powerful fan to be able to push the 30-foot distance?
290 CFM: http://www2.panasonic.com/consumer-electronics/shop/Building-Products/Ventilation-Systems/Ceiling-Insert-Fans/model.FV-30VQ3_11002_7000000000000005702

150 CFM: http://www2.panasonic.com/consumer-e...702#tabsection
__________________
Andrew


Last edited by secutanudu; 01-23-2010 at 10:58 AM.
secutanudu is offline   Reply With Quote
Old 02-09-2010, 09:50 AM   #9
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


Any thoughts on a 290CFM fan's ability to ven a 6x10 bathroom about 20 feet?

The run isn't quite as long as I thought it would be. This fan is a bit big, but only operates at 2 sones, seems like a good choice due to the long run.
__________________
Andrew

secutanudu is offline   Reply With Quote
Old 02-09-2010, 12:17 PM   #10
Member
 
Join Date: Jan 2008
Location: N.C.
Posts: 418
Rewards Points: 250
Default

Installing a new bathrom vent fan


Never vent through a soffit?

If you must always vent through the roof, how do you keep snow from blocking the exhaust vent?

My bath exhaust fan is venting into the attic close to the soffit. I know it needs correcting. Was planning on soffit venting and as the OP mentioned and blocking the soffit air holes either side of exhaust grill.
Earnie is offline   Reply With Quote
Old 02-09-2010, 01:16 PM   #11
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


Well since the bathroom is so small, I think the 290 CFM fan should be fine with the longer exhaust run (20 feet).

I'll probably go that route.
__________________
Andrew

secutanudu is offline   Reply With Quote
Old 02-09-2010, 02:28 PM   #12
Newbie Bill
 
Join Date: Dec 2008
Location: Alberta, Canada
Posts: 1,056
Rewards Points: 500
Default

Installing a new bathrom vent fan


Quote:
Originally Posted by Earnie View Post
Never vent through a soffit?

If you must always vent through the roof, how do you keep snow from blocking the exhaust vent?

My bath exhaust fan is venting into the attic close to the soffit. I know it needs correcting. Was planning on soffit venting and as the OP mentioned and blocking the soffit air holes either side of exhaust grill.
Correct, never vent through a soffit. That is almost as bad as having it directly vent into your attic. Either way, moist air will be circulating within your attic which will lead to all kinds of moisture problems, the least of which is mold.

Venting through the roof is the ideal solution. There are vent caps that are taller and reduce the likelihood of blockage from snow. Even then, the air coming out of the vent will be warm and moist. This will lead to the snow in the immediate vicinty to melt/sublimate.

Look where I live. We have roof vents for bathroom and kitchen exhaust and I have never known anyone to have an issue with snow.

But the final say should be what code requires for your area.
__________________
Bill

A DIY Noob that knows just enough to be dangerous.
drtbk4ever is offline   Reply With Quote
Old 02-09-2010, 03:37 PM   #13
Member
 
Join Date: Jan 2008
Location: N.C.
Posts: 418
Rewards Points: 250
Default

Installing a new bathrom vent fan


Not questioning the wisdom or hands on experience here, just trying to understand the science behind it.

What's the difference between 95 degree, 100 percent humidity natural environmental air being drawn into the attic from the soffit and hot humid air from the bath fan vent?
Earnie is offline   Reply With Quote
Old 02-09-2010, 03:44 PM   #14
Member
 
Join Date: Jan 2009
Posts: 489
Rewards Points: 250
Default

Installing a new bathrom vent fan


2 sones. That's pretty loud. Find something that's a little quieter.
__________________
Josh Jaros Remodeling in The Woodlands, Texas www.jarosbros.com
jaros bros. is offline   Reply With Quote
Old 02-09-2010, 03:53 PM   #15
Just call me Andrew
 
Join Date: Mar 2009
Location: Albany, NY
Posts: 2,257
Rewards Points: 1,010
Default

Installing a new bathrom vent fan


http://www2.panasonic.com/consumer-e...702#tabsection

There's one that 190CFM, 1.3 Sones. I think that'll be fine for pushing ~20 feet of exhaust.

__________________
Andrew

secutanudu is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need advise installing soffit vent scrupul0us Roofing/Siding 11 10-09-2010 08:57 PM
Shingling over ridge vent -details needed jogr Roofing/Siding 4 11-06-2009 06:47 PM
Installing vent in glass block window jasoncw Building & Construction 6 09-27-2009 11:57 AM
Installing range hood - wall vent DIYGST HVAC 3 01-04-2009 08:45 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.