Most people know there’s a pipe on the back of their clothes dryer, and that it needs to be connected to the vent pipe that’s coming through the wall or floor in their utility rooms. The common solution is to grab a piece of flexible plastic hose from the home center, stick it between the two pipes, slide the dryer in place, and forget about it. But venting a clothes dryer is a lot more than that, and it’s something that needs to be taken a lot more seriously then it typically is.
There are two basic reasons why a clothes dryer needs to be vented. As heat in the dryer dries the wet clothes, two things are released into the air–moisture, and fine fabric lint. Both need to be dealt with properly to avoid some serious potential problems.
Like the moisture generated in your kitchen or bathroom, that warm, wet air has to go somewhere. If it’s allowed to just sit in the room, or if it’s vented into the attic or the crawlspace, it can cause problems ranging from health issues to mold to structural damage.
The lint that is released in the drying process seems pretty harmless, but it’s not. For one thing, it’s initially damp, so it clings to surfaces and can transfer moisture to wood, becoming a potential source for mold and mildew. Secondly, as the lint dries it becomes highly flammable, and will flash easily into flame when it meets an ignition source.
To be effective, a dryer vent has to exit the building completely so that lint and moisture are released outside. Also, a dryer has a limited ability to push heavy, wet air, so the vent needs to be as straight and as short as possible to prevent moisture and lint from simply collecting inside it.
So, why is it not enough to take the typical route of hooking a plastic hose between those two vent pipes? For one, you probably don’t know where that vent pipe in the wall or floor actually leads. It could go straight into the crawlspace and no further. It could take a long and convoluted route up and through the attic, and even though it eventually terminates outside the building, the moist air never makes it that far. Even though venting a dryer properly is a building code requirement, it’s one that many builders don’t pay a lot of attention to, and it can be overlooked by building inspectors as well.
Another problem is with the plastic hose. Wet lint can cling pretty tenaciously to the inside of the hose, and even as the moisture dries out, the lint can remain stuck in place. As it builds up, it’s not only a fire danger in and of itself, it also affects the performance of the dryer, which in turn can heat up and become a fire hazard too. Metal hoses, which are required by most building codes, allow the moisture to condense and be removed more readily from the system, so the lint doesn’t have as much of an opportunity to linger.
The third problem is with the installation of the dryer itself. Given the location of the vent pipe on the dryer and the one that’s typically in the house, it’s a difficult task to get a clean, smooth transition between the two. What usually happens is that the hose is connected between the two pipes, then as the dryer is pushed back into place–and we naturally want to push it back as far as possible to maximize space in the room–the thin, flexible hose is often crushed and pinched into a highly restricted mess that loses much of its efficiency.
One solution is to use one of the new dryer vent boxes that have made their ways onto the market in recent years. Vent boxes are special metal cans that are installed between the studs behind the dryer and offer a smooth transition point for termination of the house vent inside the wall. And because they are recessed between the studs, they also allow for a clean, easy, kink-free connection between the clothes dryer and the vent. For more information, check out the Dryerbox at www.dryerbox.com.
Here are some other tips to ensure your dryer is working safely and efficiently:
_Examine the connection between the dryer and the house vent pipe. Make sure the hose is smooth and undamaged. Replace plastic hoses with metal.
_Try and determine where the vent pipe leads. Make sure it exits the house, and that all connections are intact.
_Clean your dryer’s lint trap or screen after every load. Do not allow lint to accumulate inside the dryer.
_Watch the operation of your dryer. If the dryer is taking longer than usual to dry a load of clothes, or if the outside of it feels unusually hot, these are indicators of possible venting problems.
_Do not operate the dryer when you’re not at home.
_Do not use a “waste heat” device, which has been marketed as a way of getting supplemental heat inside your home by routing the heat from your dryer vent back indoors. This also puts a lot of wet air into the house–the opposite of what you’re trying to achieve.
_Avoid add-ons and gimmicks designed to “improve” dryer efficiency or eliminate venting.
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