Gas Dryer Exhaust Vent Length

The chart below shows the manufacturer recommendations for maximum vent length under various conditions.

Gas dryer exhaust vent length. The international residential code irc states that the maximum length for a dryer vent is 25 feet according to the national association of certified home inspectiors website. The first step of installing a dryer vent in a new location is to map out a path for the ductwork. The maximum length of a straight run of dryer duct is 35 feet with a 5 foot deduction in length for each 90º bend and half that for 45º bends based on using a 4 inch smooth metal vent with no screws protruding into the air flow. The airflow of a dryer depends on the design of the exhaust vent.

Most dryer ducts are round and 4 inches in diameter. The vent should be as straight as possible and the code sets a limit of 25 feet on its length. Your new dryer is shifted to vent to the rear. If you have to install bends you should reduce this limit by 5 feet for every 90 degree bend and 2.

The exhaust airflow of any whirlpool produced dryer at the maximum rated vent length is at least. Clean old ducts before installing the dryer. Do not use plastic or thin foil ducting. The recommendations can change from model to model even on the same brand s products so consult the owner s manual or installation instructions for your specific model.

Because all types are sold for use with dryers you would naturally assume that all are suitable for this application. The exhaust duct run should be as short as possible. The length of the run should be no more than 25 feet. Some are flexible and others are rigid.

The route should be as short as possible but there are other guidelines to follow when venting a dryer. Let s start with what the irc international residential code says. Dryer vent hoses that are run in a straight line from the dryer exhaust to the outdoors provide the best ventilation and reduce the likelihood of trapped lint. When using a straight piece of flexible metal vent hose the maximum length allowed for safe ventilation is approximately 30 feet according to the appliance aid website.

The ductwork recommended for use between the dryer in the wall should be rigid or semi rigid modeled ducting that is 4 inches in diameter. That 25 feet is based on a straight run of vent piping if there are any bends in the line. Long runs of vent line with multiple bends reduce the flow of air often to the point where the dryer exhaust doesn t even reach the exhaust vent. However there are a lot of variables that can enter into the equation.

Vent length for vertical installations should likely be considerably less than the. The international residential code irc section m1502 clothes dryer exhaust guidelines states that a dryer exhaust duct should not exceed 25 feet from the dryer to the exhaust vent in the wall or roof.