Dryer hazards are preventable by checking vent connections, preventing vent restrictions, cleaning dryer lint traps and clearing obstructions in the vent ducts. Restrictions or obstructions cause the dryer to work harder, leading to overheating, which can cause a fire. The highly flammable lint spreads the fire quickly.
The ducts leading to the dryer vent play a role in safety. Ducts with a smooth interior made from rigid metal reduce potential hazards. The ducts should be no longer than 25 feet, but that maximum decreases with any bends in the duct because of air restriction. A 90-degree angle cuts down the maximum by 5 feet, while a 45-degree angle takes off 2.5 feet.
A duct of any length should be free of kinks or compressed areas, which slow down the air flow. Restrictions or blockages in the ducts cause lint to collect. If a fire starts in the dryer, the accumulated lint provides fuel for the flames that lead right to the wall. A full lint trap in the dryer also increases flammability and spreads the flames.
Lint isn't the only potential blockage source. A bird might build a nest at the exhaust end of the duct. If the exhaust is unprotected, other outdoor debris can clog the exit. Regularly looking for and removing obstructions helps keep the dryer vent safe.