Did you ever burn a hole in a dry leaf with a magnifying glass? Until the lens focuses the light to a shining pinpoint, nothing happens to the leaf. You have to move the lens back and forth until you get it at the right distance to focus the light. Only when it is at its brightest and hottest does the leaf smoke and smolder. And that's exactly what happens with the dryer when the dryer vent is blocked.
The clothes dryer generates heat to dry your clothing, but it won't set them on fire, even if the cycle runs too long. This is because the dryer was designed to vent the hot air and expel it through the dryer vent duct and to the outdoors. For safety's sake, this duct should be as straight and as short as possible. And it works perfectly, just like it was designed to do, as long as the vent remains clear.
A clothes dryer has a lint filter that you're supposed to clean off after each load to ensure proper air flow. The filter captures much of the lint that detaches from your clothes and towels in the course of drying, but some of it gets past the filter and collects in the body of the dryer, around the drum, and it also passes into the dryer vent. It clings together with static electricity, and it is damp from the humid air exiting the dryer. It sticks to the walls of the dryer vent, drying into a dense mass, very similar to Papier-mâché. Over time, this accumulation of hardened lint can block the dryer vent and restrict air flow.
Picture what happens when the dryer vent is blocked. You've got hot air, which expands in volume, being funneled from the larger space inside the dryer into the narrower dryer vent duct. The air gets hotter as it compresses, hotter than it was inside the dryer. And then it stops, because the duct is blocked. The heat is focused there, just like with that magnifying lens. And then you have the perfect storm. Not only is the duct blocked, but the dryer lint blocking the duct is highly flammable.
The National Fire Protection Association recommends that your dryer vent pipe be cleaned at least once a year, or as often as necessary. If your dryer starts taking longer than it used to dry a load of laundry, it can be a sign that the dryer vent needs cleaning. For further information, see the NFPA website.
Air Duct Cleaning Baltimore can clear your dryer vent quickly and completely with our vent cleaning equipment.