Have you ever wondered why your clothes were still damp after running a dryer cycle? Have you ever wondered why the area around your dryer is always cold in the winter? Have you ever wondered why the heating element burned out? Has a dryer cycle ever just stopped? The answer to all these question and maybe some others “could” be related to your dryer vent.
The dryer draws air in and exhausts the damp air out through the dryer vent. If you have a gas dryer, the vent is even more important. Exhaust air passes through a “lint screen” that is supposed to catch lint that comes from wet clothes. Lint screens do not catch all the lint, hence one of the big vent problems. Lint mixed with damp air can make a paste like substance which can stick to the inside of the vent pipe. This is the reason why dryer vent pipe sections should be properly overlapped in the outgoing direction and should not be screwed together. Joints that overlap in the wrong direction along with screws that stick into the air passage can and will collect lint. Any of the pipe joints should be sealed with aluminum type duck tape, not the cloth type duct tape that can dry out and become worthless.
Over time the vent pipe can become completely clogged with lint eliminating that flow of air. When this happens, your clothes will not dry, the dryer may short cycle or shut down by itself because it has over heated or even worse allow the heating element to burn out.
Sometimes, during home inspections, I see the vent outlet completely clogged. The outlet fitting should have a damper door or louver type doors that should open with air flow and then close when the dryer is not in use. When the outlet is partly clogged or stuck open, outside air can find it’s way back into your home when the dryer is not running. This problem is very noticeable in the winter when it’s cold air coming back in making heating the home more expensive.
When hooking up a dryer to a vent system in your home, use materials such as flexible aluminum piping that is smooth on the inside. Materials that are corrugated tend to disturb good air flow, will catch lint rather than letting it pass through and make cleaning almost impossible. Keeping the damper door or screen on the outside fixture clean and free flowing is important too. Keep in mind that a good vent system is one that is as short and straight as possible with the discharge far away from your air conditioner.
The dryer must vent to the outside and not into the attic, crawl space or basement. The damp air alone can cause other problems like mold and rot in a crawl space and the same or other issues if allowed to exhaust in the attic or basement. Section joints in an attic can become clogged so bad that back pressure can actually blow a joint apart. I have seen this where a stained ceiling was thought to have been caused by a roof leak, but was in fact a dryer vent joint that came apart and allowed the damp moist air to blow out into the attic. Over a period of time, enough moisture caused a stain on the ceiling. Attic conditions are best when the attic, outside air and humidity are about the same.
