DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   HVAC (
-   -   How far to run dryer vent? (

bigmark77 11-28-2011 06:38 PM

How far to run dryer vent?
I bought an existing home without an outside dryer vent. The w/d had been moved from the basement (and all connections and vent sealed off) to the middle of the house. The previous owners simply vented their gas dryer through the 1st floor room into the basement through an unfinished spot. That's a no-go for me. I need to run a vent for my dryer now. The closest exterior wall is 12 feet away. I can run the vent along a joist bay but I have to go through finished ceiling and then end up smack into an existing deck with no access under. I have a crawl space I can access and run the vent to an outlet near other vents next to my a/c unit. But that route is 36 feet.
Question: Can I safely run gas dryer vent 36' with at least one 90 or at least a 45 bend 6-9 feet prior to exit? If so can I use 4" pvc? Will I have a problem with water vapor collecting in this long pipe? Should I pitch it up or down and how much? 36' is a long way in my mind.

sammy37 11-28-2011 07:31 PM

I wouldnt use pvc for the dryer vent, use the 4" round metal pipe.
As far as the length, 36 feet is going to be a long stretch for that thing, especially adding the extra fittings that you want.
Try to find another route that isnt as long.

Also, dont use screws in the metal piping when you assemble it, the screws will attribute to lint buildup

bigmark77 11-30-2011 03:02 PM

Not what I wanted to hear but I was hoping for the best. the long run worries me so I better go shorter. I can't go out back without re-doing a deck. I may have to look at a front of the house option. Thanks for the reply.

BSB00 11-30-2011 06:49 PM

35 Feet
45 degree counts as 2.5
90 counts as 5

No Screws into pipe tape only

IBC 2006

Gary in WA 12-03-2011 06:12 PM

I recommend a shorter route to prevent lint build-up and condensation. Look up your dryer model on line for the maximum safety run. Use a type "A" termination hood rather than Type "B' for 50% more opening door flapper;

No flex pipe, screws, or pitch; metal smooth-walled pipe only:
Exit hood 3' minimum from other openings (door, window, fresh-air intakes) to building as per code.


joecaption 12-03-2011 06:16 PM

Middle of the house is the worst place for a location for a dryer.

sammy37 12-03-2011 07:27 PM

Our dryer is in the middle of the house, our vent used to run horizontaly all the way through the attic to the end of the house. When I replaced my roof in the spring, I ran a new vent straight up through the roof and did a goosneck with two 4" adjustable 90's, works great.

To the OP, can you run your vent up through the roof?

Missouri Bound 12-03-2011 08:56 PM

Appliance411 FAQ: How long can my dryer vent be? Maybe this will help your decision....scroll down to see mfg. details and specs.

hvac122 12-03-2011 09:17 PM

Code here is 20' and 1 elbow. The only way it can be longer is if the manufacturer allowes it and we need to prove that with specs to the inspector. 35' is way to long.

Blondesense 12-04-2011 12:08 PM

I know this isn't what you asked, but have you taken a good hard look at the washer too. Does it have the proper hoses (not the old black rubber ones), a pan with drainage, or any warning system if there is a leak?

I'm no expert, but if the PO installed the dryer like this, it makes me wonder what kind of a job he did on the washer.

I know it's a lot more convenient to have them upstairs, but between the major repair $$$ a leaking washer can cause, and the potential CO issues of a gas dryer, I would give serious consideration to moving them both back to the basement.

Edited to add: Welcome to the forum, too! I was born and raised in Lake County.

All times are GMT -5. The time now is 07:32 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1