Anybody know anything about venting a clothes dryer?

[VictoriaL]

I've posted this on a GardenWeb subforum that deals with laundry rooms, but thought I toss it out here because we need an answer asap (provided the contractor actually chooses to show up tomorrow).

We have 3 options (well, actually 2, option #3 is a bit "out there") for venting our gas clothes dryer. Can anyone please advise which may be the best one?

1. Go out the back of the dryer, a 90-degree turn straight up 8' through the roof.

2. Out of the back, a 90-dgeree turn up 4',another 90- degree turn, then a 9' horizontal run to go through an outside wall.

3. Go out the back,a 45-degree turn down to the floor (run of about 4'), then 4 45-degree turns, along a 14' horizontal run out to the outside wall.

The question basically is, will the venting work better to come out of the dryer at 90-degrees and go up 8', or is it better to not vent vertically at all and go mostly horizontally even with a bunch of turns in the ducting? I realize that lint can collect at all turns, and that most places advise against ducting a dryer up through a roof, but these really are our only options at this point.

Our contractor is a total idiot (sorry, it's me who is "venting" now...)

[Cafe Latte]

I've never had a laundry room that wasn't along an outside wall, so I am confused where yours is located within the house. However, I would not want the venting to run up - since what goes up must come down, so whatever option that would be for you - with the least distance to to the outside, is what I would pick. Hope someone can help you more.

[Cafe Latte]

Here is some info that might help.

http://www.appliance411.com/faq/dryer-vent-length.shtml

[MinEaston]

Vicci - your option #2 is just about what I have, only I go out the back of the dryer, 90 degrees down about 2 feet, then 90 degrees and out at least 8 feet. Be sure the elbows used are fastened securely to the rest of the ducting and don't have any places where lint can get caught. Mine weren't, and I had to have someone go back and figure it all out when the dryer stopped working correctly.

We were strongly discouraged from going straight up and through the ceiling, but that may have been more due to the work involved. The duct work as described above goes through the crawl space so it's easily accessible.

[VictoriaL]

Thanks for your input.

The washer/dryer (a combo unit) is on an inside wall. It was next to an outside wall, where it was previously vented, but the room was enlarged. Now there is no room for the unit to be moved to an outside wall (since we would need to move plumbing as well and the room is built on a concrete slab).

MinEaston, I was leaning toward #2 as well, since (what Cafe Latte said) what goes up... and that's a lot of lint accumulation. Unfortunately, our ducting will not be hidden in a crawlspace since the contractor finished those walls before he decided to look a few steps ahead...

Also, MinEaston, does your dryer seem to take care of the lint problem through the in-unit filter, or did you install some sort of filter near the elbows, or just clean out the ducting regularly?

[Valerie226]

I clean our dryer filter every use and our vent still developed a block. some birds set up housekeeping in the vent area and semi blocked it, and then dust started backing up.
important you can get to both ends of the ducting. we can blow ours out with a leaf blower.

[MinEaston]

Also, MinEaston, does your dryer seem to take care of the lint problem through the in-unit filter, or did you install some sort of filter near the elbows, or just clean out the ducting regularly?

I clean the dryer filter each time I use it, and the guy who fixed the venting said to stick a shop vac hose down there two or three times a year to take care of the issue. Once the weather gets consistently warmer and the painters are done outside, I'll hang more than I use the dryer, so the venting will get a respite.