What Is The Maximum Length For A Dryer Vent Hose

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.

What is the maximum length for a dryer vent hose. These guidelines will usually provide a maximum length for ductwork venting a dryer. 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. The maximum length of the duct shall be reduced 2 5 feet for each 45 degree 0 8 rad bend and 5 feet for each 90 degree 1 6 rad bend. Transition ducts must not be concealed inside walls or other building cavities and usually have a maximum allowed length of eight feet.

The vent should be as straight as possible and the code sets a limit of 25 feet on its length. Vent cap with wide four inch opening or mini louvers and smooth metal pipe total pipe length can be 64 feet with no bends. Use the tables below to calculate how far your vent can be from the dryer. 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.

Because the weight of the moist dryer air is much heavier than ambient air i would think the maximum vent length would be less than 1 2 or 1 4 of the acceptable length of a horizontal vent run. Pay attention to the type of pipe you have and the vent configuration. If you have no choice except to vent through the roof purchasing a extended vent dryer if available might help but still keep the total vent length well reduced of the manufacturer s recommendations. However there are a lot of variables that can enter into the equation.

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. However that 25 ft. Let s start with what the irc international residential code says. 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.

If you have to run a long length of duct you should consider the local building code. If you have to install bends you should reduce this limit by 5 feet for every 90 degree bend and 2. Foil duct is held in place with dryer clamps or large hose clamps. A rule of thumb to follow is that it should have a maximum length of 25 feet.

The maximum developed length of a clothes dryer exhaust duct shall not exceed 35 feet from the dryer location to the wall or roof termination.