Keeping your dryer vents clean is important for a number of reasons which include not only energy savings but safety.

A dryer works by pushing out hot, moist air so your clothes can dry. If your dryer vent to the outside becomes blocked by lint, the air will not be able to expel moisture like it was designed to do. The result will be trapped moisture that takes more heat energy to evaporate.

If you start to notice any of the following, it’s likely you have a clogged dryer vent:

It takes longer to dry clothes

With hot, moist air kept inside the dryer drum, it takes much longer and more heat to dry the clothes. This is hard on your dryer, your clothes, and reduces the life of both.

Clothing is hot to the touch

Clothing is supposed to be hot and fresh from the dryer, right? Wrong. If your clothes – or your dryer are noticeably hot to the touch at the end of a cycle, it means the dryer is not exhausting through the vent properly. Everything overheats – and overheating is never a good thing.

You smell something burning

Bad news – lint is very flammable, and when it builds up in the exhaust vent, lint trap, and drum casing, it can actually catch on fire.

Why Dryer Vent Cleaning Is Essential
Energy efficiency. Over time, your dryer vent (which carries away water vapor produced by the clothes drying process) gradually gets clogged with dust, lint, and hair from your laundry.
Obviously, a blocked vent won’t do its job as well, meaning that the dryer spin cycles will become less efficient and drying times will be 2 or 3 times longer than normal. Besides the increased wear and tear, your dryer will require more electricity or gas to operate, raising your fuel bills.

Relative humidity regulation. Another side effect of a clogged dryer vent is higher indoor humidity. The lint buildup insde the venting system acts like a sponge, absorbing and holding moisture from the dryer, rather than channeling it safely outdoors.
This raises the relative humidity above the ideal of 30-50 percent, leading to dampness-related problems such as condensation on your windows. If untreated, the eventual result is likely to be mold damage to your house.

Safety for your home and family. Clogged vents threaten your household’s safety. They increase the likelihood of short circuits and other electrical hazards and in the case of gas dryers, prevent proper exhausting of carbon monoxide.
In addition, they cause the dryer to overheat, a serious fire risk. The US Fire Administration reports an annual 100 injuries, 5 deaths, and $35,000,000 in property loss from residential clothes dryer fires. The leading cause of dryer fires? Quite simply, failure to clean the dryer.