Dryer vents have a long unfortunate history of causing tens of thousands of house fires. Dryers depend on a 4-inch diameter, unrestricted, metal vent to exhaust the hot, moist, air to the outdoors. Many people regard the vent as a necessary evil and hardly give it another thought. When the dryer takes longer to dry a normal size load, most people don’t understand why.
Hidden Dangers of Dryer Lint
If homeowners take quick action and get help to find out the reason behind long dry times, most dryer fires wouldn’t happen. When a dryer suffers from a blocked or restricted vent, lint won’t get exhausted outdoors, but instead, inside the dryer or the vent. Over time, the lint builds up and creates a restriction or blockage that builds up inside the dryer and makes its way to the source of the heat.
Imagine for a moment what happens when dryer lint comes into contact with a glowing red heating element or the open flame of a gas burner. Lint inside the dryer ignites quickly and uses air from the vent to help it grow. After ignition, the flame follows the path of the vent and ignites the lint inside the vent.
Most contractors route vents inside walls and in ceilings of rooms before they exit the house. A lint fire has the potential to burn through a non-metal vent and catch a house on fire. If that isn’t bad enough, the dryer itself suffers irreparable internal damage caused by the fire.
Learn to Prevent Dryer Fires
Dryer lint is very dangerous, and it’s wise to learn how to prevent a dryer fire. To put the danger of lint into perspective, some camping materials suggest using a ball of lint as a firestarter because it ignites with a single match.
Aside from common sense, such as regular vent cleanings and dryer maintenance, replacing your old vent with rigid or flexible metal vent (rigid preferred) offers the best assurance that if a lint fire starts, there’s a better chance it stays contained inside the vent without spreading to the interior walls. The length of the vent determines its efficiency and can cause restricted air flow if not installed properly.
In every case, replace your vent if it’s plastic or foil. These materials burn and increase the chance of a dryer fire traveling through the vent and igniting interior walls of your house.
Length vs. Efficiency
Many times vent installers lack knowledge of proper venting for dryers and without knowing, they cause another problem that’s more serious than what they’re trying to prevent. According to International Residential Code (IRC), Section M1502 states metal dryer vent length is no longer than 25 linear feet. If there’s a bend or 90-degree turn, for each turn or bend, deduct five feet from the 25 foot maximum for the new maximum length.
The efficiency of venting decreases as the length of the vent increases. The limitations of your dryer’s blower motor help determine the dryer’s efficiency. Use the shortest length of a metal vent and keep it as straight as possible to assist the air flowing through it.
Is dryer lint really that dangerous? Yes, it is. Remember the importance of dryer safety and regular vent cleanings. Dryer vent cleaning isn’t a simple task as many think.