Prevent dryer vent air infiltration in an apartment complex

January 8, 2012 10:16 AM

How do I prevent dryer vent air infiltration in an apartment complex?

We just moved into an apartment with a washer and dryer in the unit. Every night the apartment smells like food because our dryer vent is directly above the kitchen window of the apartment below. Is there anything we can install inside the unit to prevent air infiltration?

posted by MediaJunkie to Home & Garden (8 answers total)

Duct tape over the dryer vent will not let air pass through. But you'd have to remove this every time you want to use the dryer, so I'm not sure how practical it is. Basically, anything which will not let air pass through the vent into your apartment would have to be removed when you use the dryer and want air to move outside your apartment.
posted by dfriedman at 10:20 AM on January 8, 2012

As long as hot air is blowing out, it's less likely that stinky air will drift in, so dry your clothes around suppertime.
posted by Sys Rq at 10:24 AM on January 8, 2012

They make flaps that go over dryer vents to prevent this.
posted by fshgrl at 10:40 AM on January 8, 2012 [3 favorites]

If you don't have one already, I think that fshgrl's recommendation of a flap is a good starting point. If you're looking for something a bit more heavy-duty, I've seen motorized vents on exhaust fans that open (with an electric motor, typically) only when the fan is on. I don't know if these would work for a dryer vent, but it might be a good start. "motorized dampers" is apparently a good phrase to search Google to find these things.
posted by Betelgeuse at 10:48 AM on January 8, 2012

Are you certain that the problem isn't that your dryer duct is connected to your neighbour's kitchen exhaust fan? This seems like a more likely path for air to flow, as generally you will have positive air pressure in your apartment, at least in the winter, which will lead to air flowing out the dryer vent, not in.

If it really is as you describe:

There should be a louvre (closing flaps) outside on the dryer vent that would prevent this. They cost about $5.

If that isn't possible, you could install a butterfly damper (metal disc inside the duct that you can rotate from the outside) on the end of the dryer duct, but this won't block every last bit of air flow.
posted by ssg at 10:52 AM on January 8, 2012

They also make one way valves that install inside the vent line.
posted by gjc at 11:20 AM on January 8, 2012

Backdraft prevention dampers. These are "mechanical" in that they have butterfly flaps or other moving parts. See also this "non-mechanical" type which has a fabric sleeve that opens when the blower is on and collapses flat to prevent backdraft when it is off.
posted by beagle at 11:43 AM on January 8, 2012

By the way, be sure it is really the dryer vent that's causing your problem. Just disconnect your dryer exhaust and stuff something in there to prevent air inflow. If you still get your neighbor's cooking odors, then they're seeping in some other way, such as cracks and crevices in the floors and walls. If this is the case, you'll need to take other measures, like caulking and creating positive air pressure (a fan to push air into your apartment so it pushes out through the cracks, instead of allowing air from downstairs to siphon into your place).
posted by beagle at 11:52 AM on January 8, 2012