Why shouldn't a clothes dryer vent to the underside of a mobile home?

Question

I have a manufactured home in Yuma, Arizona (summer temps in the 115 - 125 range) that has a clothes dryer that vents into the space underneath. All of the places that sell dryers, and sevral books, say NOT to vent underneath. One complicating factor is that the home sits in a pit that is pretty much level with the cement pad around it. It would be very difficult to run a vent to the outside; but, if safety is a factor, I certainly will.

I guess my question has several parts. (1) Why shouldn't a dryer vent underneath? (2) Is there an easy way to vent when the vent hose would not be able to break into the air? What is the danger of venting underneath?

Thank you all in advance for the help.

Answer 1

The two major factors in venting underneath are moisture from the vent creating an environment for molds and mildew to grow and the second is an accumulation of lint that may cause the vent to become blocked and creating a possible fire hazard. Your options would be to cut through the wall and mount your vent that way or use an indoor venting system sold in most hardwares. If you keep the vent clean and regularly clean the lint screen and get a lint brush to clean out the pipe from there I don't believe you have anything to worry about with your current set up as long as you can get to the pipe underneath and check it for clogs once or twice a year.

Answer 2

Installing A Dryer Vent Hose

Answer 3

Have you ever stood by the vent when the dryer is running? It gets hot. Blowing hot air under the trailer could potentially ignite something and start a fire. Sometimes lint is also blown out and if it should accumulate and then catch on fire I am sure you can understand the dangers of a trailer on fire. They burn quickly.

Depending on the layout of the trailer and where exactly the laundry is being done will determine how you can vent it out. There are several options but without knowing the layout I couldn't suggest anything.

Answer 4

I'm just guessing here, but the dryer produces humidity, and lint. Can you imagine all that sticky lint underneath your home? I would think the humidity would mess with the wood and the electrical too. Mine is vented outside and I see the gack it sends out. BTW, I live in a mobile too. Wishing you the best of luck and hopefully some more useful information than mine.

Answer 5

If you lived where it got cold I could understand cause the warm dryer air blowing into the cold air would cause a mildew problem from the moisture it would create, they sold kits where you could put the warm dryer air right into your basement to help warm it in winter months so I'm not sure where any danger comes in. You might want to go to your town hall and check your codes, you know how government works , they'll find a way to get a dime out of you. Good luck, it's 9 degrees here.

Answer 6

You will likely not have any problem at all, considering where you live but the standard response from anyone in the dryer business is not to vent into the crawlspace because of moisture buildup --something that you certainly won't have a problem with in your climate. You will get a lot of lint under there, though.

In climates where moisture buildup is a problem, certainly one would not want to dump all of that moisture under the floor of the house.

Answer 7

The problem if it is electric is moisture/humidity from the dryer. If it is gas co2 and moisture. If your home has no skirt and it is electric don't worry about it. if it does just extend the hose to vent out of the skirt.

Answer 8

Humidity,lent,and CRITTERS.The air that comes out of a dryer is very warm and needs somewhere to escape.If underneath a t-house it gets trapped and causes moisture.the only thing protecting the floor is the insulation.over time the elements will start to REEK havov underneath.The lent is a FIRE danger and will attract to the insulation and make it very DANGEROUS. The mild winters will put out a WELCOME HOME sign to all the CRITTERS giving them a nice, warm place to cuddle-up. Believe me, those CRITTERS will find a way in. I hope this has been usefull information.

Answer 9

The biggest problem with dryer lint is its combustibility.

"I read an article about fire starting, where Colleen O'Brien writes of how dryer lint makes a fabulous sparker in adverse conditions. She says to stuff a film canister with all the lint you can squeeze in (several dryer loads can be stuffed in if you try); then fill a second canister with vaseline-smeared cotton balls. She writes that lighting the lint, even in the worst wet conditions, will bring enough heat to start the cotton balls...which will flare long enough for your kindling to catch. I've tried this in the miserable soggyness of Northern Minnesota, and can vouch for its effectiveness."

Lint builds up in the exhaust pipe and inside the dryer, it slows the air flow through the dryer and out the exhaust. Lint accumulation and reduced airflow are conditions that feed on one another. These conditions cause early motor burnout and heating element overload which can cause extreme heat and Fire!Further, the slower air movement causes more lint to collect on the inside of the dryer,usually around the heating coil,and backside of the drum. The lint gathers on the motor,electrical connections inside the dryer acting as an insulator, reducing the motors ability to cool the windings causing Heat overload (FireHazard!).

Lint, the annoying byproduct of drying clothes, is also a fire hazard. That's right - excess lint can ignite. Usually such a fire starts after reduced airflow in the ventilation system causes lint buildup and overheating. The Consumer Product Safety Commission estimates 16,700 dryer fires occurred in 1997 (latest available statistics from CPSC). Of these fires, the commission reports 30 deaths and 430 injuries.

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Enough of the warnings. You need to install a proper dryer vent.

Venting a clothes dryer to the outside isn't an option - it's a requirement. An unvented dryer puts all kinds of fibers and lint into the air in the house that will not only accumulate and make a heck of a mess over time, but can cause respiratory and breathing problems for the occupants. Even more important, the hot air in the dryer (as a result of combustion) may contain gasses such as carbon monoxide that are extremely hazardous. These need to be vented to the outside.

Luckily, installing a dryer vent is a pretty straightforward job. As long as you can measure accurately and use a power drill or jig saw, you can install your own dryer vent.

What you'll need:

Power drill
Hole saw
Tape measure
4 inch rigid sheet metal pipe
Dryer vent
Caulking gun and silicon caulking
Foil tape
Screwdriver and wood screws
Ladder (possibly)

Determining where the vent will go

The first thing to do is figure out where you want your dryer vent to be placed. If your dryer is in the basement, you want to drill through the wooden sill plate that sits on your foundation.

If your dryer is on the main or second floor, you will need to determine where you can cut a hole through the wall. When you think you've found the proper location, drill a small pilot hole and insert wire coat hanger bent at 90 degrees and spin it around. If the hanger doesn't hit anything inside the wall, your location is fine; however, if it hits something in the wall you'll need to find another location.

Check the vent locations from the outside as well. Do this by measuring (on the inside) from the corner of the foundation or even a window to your chosen spot, and then go outside and use the same measurement to verify that your location is OK. You don't want to be running into any existing shrubbery or even gate posts.

Installing the Vent

Once you've established where your dryer vent is going, drill a small pilot hole from the inside. Go outside, and using a 4-inch hole saw, cut the hole for the dryer vent pipe. You can use a smaller hole saw and a saber saw to cut the hole, just be sure to mark the location of the vent pipe with the pilot hole in its center.

Install the vent hood or shroud to the side of your house using rust resistant wood screws, and caulk all around the pipe and the shroud. The vent hood should have a piece of pipe about 12" long already attached to it.

On the inside, attach a 90-degree elbow to the protruding end of the vent pipe, and then run sections of vent pipe back to your dryer. At the dryer, you'll need to attach an elbow where the exhaust comes out of the dryer and then connect the vent pipe to the elbow.

Your dryer vent is now basically finished. All that's left is to slide the dryer back into position and make sure it's level.

Final Thoughts

Use large hose clamps to attach the solid vent pipes to the elbows, and use foil tape to seal the joints between the pipe sections. Never use sheet metal screws to join the sections together - they will protrude into the pipe, where they will catch and hold lint that eventually could block the vent pipe.

One final word. Flexible plastic hoses were commonly used for venting dryers in the past. However, these hoses aren't strong enough to support their own weight, so they will sag, and lint will collect in the low spots, creating a possible fire hazard. Don't use them.

Answer 10

i can answer the danger part.your lint trap does not catch all the lint.some is vented out and dryer lint ignites easily .it is a fire hazzard to vent underneath.