Minimum length for dryer duct and best ducting material

[dylanmitchell]

Just swapped out the foil duct for semi-rigid duct on my gas dryer a Speed Queen Speed Queen ADEE9RG. Is there a minim length or number of bends for dryer exhaust ducting? Old machine was installed with close elbow and hooked turn semi-rigid ducting.

Photos are of foil duct installed by delivery guys, semi-rigid duct I swapped in, and prior snaked ducting. It appears that some foil ducting is UL approved and semi-rigid ducting like the one I got is also UL approved. Still, think that semi-metallic is a better way to go and lower fire danger.

Thanks.

 

[yogitunes]

as long as it stays like in pic #2, you should be good to go.....

there really is no minimum....but maximums, yes!....usually no more than 8ft and two elbows...total length from machine to outside exhaust...give or take...

you might want to consider, taking either a 2x4 or 2x6 and lay that behind the machines, it will prevent anyone pushing it towards the wall and crushing the vent pipe...

 

[powerfin64]

I agree with Yogi

Keep the duct as short and straight as possible.

I very recently replaced my duct with new semi rigid duct with collared ends,

which make connections MUCH easier. Then used aluminum tape at all the connection

points for no air leaks. I see a difference in drying time since I've sealed all the connection points(including at the vent hood coming through the wall.)

The most elbows that could be used is 4. Im using 1 close elbow on mine, but mine is a very short duct run to the vent hood coming through the wall.

 

[wayupnorth]

I have the same hose from my Maytag electric dryer. But since I dont use it alot, I dont have it going thru an outside wall. I keep it inside with one of those flip inside or out. There is a window next to it and an insulating board that fits in the window just fine around the vent. Too much cold air comes in a dryer vent here. Those that dry several times on a daily basis, yes. Me, using the dryer every other week, no. After forgetting to start the dryer until the next morning in this sub zero weather to wake up and find a frozen blob many years ago.

 

[dylanmitchell]

Thanks for the comments. 2x4 or 2x6 is a great idea. We're in San Diego and don't see those temps but I do want to add a rodent guard around the outside. Something metal that has minimal impact on air flow and you can blow lint out of with a can of air or suck up with a wet dry vac.