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. 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.
Vertical/horizontal not a concern. 35 feet max run, 90 degree elbows calculate to 5 feet. 45s Calc to 2.5 feet. 6 feet max flex duct from dryer to solid.
The standard maximum distance your dryer duct can run is 25 feet from end to end. Some brands can go up to 35 feet, but you'll need to check manufacturer instructions and local regulations.
There is only code to dictate the height of the exhaust above exterior ground. There is no code for interior height. Standard puts the top of the vent pipe typically around 12" off the floor.
DO NOT terminate dryer vents in crawl spaces or attics. Dryer vents that terminate in crawl spaces or attics allow for moisture to deposit and encourage mold growth and health hazards. Dryer vents must terminate outside of the building.
M1502.
According to the M1502. 5 code, the construction of a dryer duct has to be a minimum of 0.4 mm thick with a smooth interior. This means ribbed vents are no longer being used. Additionally, all duct joints must point in the direction of airflow.
Per the requirements of the International Residential Code, Section M1502 (2009-2021 IRC), the clothes dryer exhaust duct should be a rigid or semi-rigid metal duct made of galvanized steel or galvanized aluminum with a smooth interior finish and a duct diameter of 4 inches.
Venting a dryer through the roof is possible, but there are important considerations to remember. This method can be practical when sidewall venting isn't an option due to your building's layout. However, overall, sidewall venting is considered the safer option.
Exhaust systems longer than the manufacturer's recommendations can extend drying times, affect appliance operation and may encourage lint build-up on pipe lining.
Route the dryer vent horizontally to the home's outside wall. Duct work should pitch 1/4-inch per foot to the outside. This keeps moisture out of the pipe. For basement laundry areas where your ductwork will run vertically to the outside wall, you may need to use 90-degree elbows.
Some places or building codes may not allow indoor dryer vents due to safety concerns, so check your local rules.
Yes, that's considered safe. The operating temperature of a dryer vent is not a problem for direct wood contact. Keep the vent clear and you'll have no fire. Ensure all joints are foil taped, so lint does not escape from the pipe.
This means that vents should also be as straight as possible and cannot be longer than 35 feet. Any 90-degree turns in the vent reduce this 35-foot number by 5 feet, since these turns restrict airflow.
In situations where outdoor venting is not an available option, the vent bucket serves as an efficient indoor solution. It collects lint and moisture, ensuring they do not disperse throughout your living area. It is particularly convenient for apartments or temporary setups.
The dryer vent you install on a roof creates a path for the hot, moist air from the dryer to escape outside the building. This helps to prevent a buildup of excess humidity and heat, which can cause problems such as mold growth, and fire hazards.
With home maintenance, some shortcuts can lead to big problems. One of those shortcuts is venting your clothes dryer into the attic. It may seem convenient, but it violates building codes in most cities because of its hazards.
Avoid Long Vertical Runs: If vertical runs are necessary, they should be as short as possible. Long vertical runs can result in greater humidity and lint accumulation, which will reduce drying efficiency. Vertical runs may require the installation of a booster fan to maintain effective exhaust air flow.
In most cases, rerouting costs $75 to $100 as long as no structural changes to the home are needed. This project is done if the vent doesn't route to the outside or if you find the hoses have too many bends. The cost to reroute a unit depends on the accessibility of the job.
Venting a dryer through the roof should be your last option, if possible. You almost always want it to go through sidewall vents, which are less likely to get clogged and are usually much easier to access. Even if your dryer is placed on a floor other than the ground floor, you can still manage a sidewall vent.
The maximum length of a 4-inch (102 mm) diameter exhaust vent shall not exceed 35 feet (7620 mm) from the dryer location to wall or roof termination, and shall terminate with a full opening exhaust hood. A reduction in maximum length of 2.5 feet for each 45-degree bend and 5 feet for each 90-degree bend shall apply.
Some dryers can exhaust beyond 25 equivalent feet without a booster fan. Dryer Duct Booster Saves significant energy - reduces drying times 50% or more. Reduces lint build-up, dust & fire hazards by maintaining proper velocity in duct runs up to 150 equivalent feet.
Dryer Vents should never be longer than 35 feet
The 4″ smooth metal pipe between the laundry room and the outside should never be longer than 35′. 5′ should be subtracted from the 35′ number each time a 90-degree elbow is used. GOOD! Flame-resistant steel 90-degree metal elbow for dryer ducts.
conditions should be at least 1,200 FPM (feet per minute) to keep lint moving through the vent. (In a 4" (102 mm) diameter pipe, this requires at least 105 CFM of air flow.) Back pressure should be measured with an empty dryer, a clean lint screen and with the dryer operating in the Air Only cycle (no heat).
You can use a 4-inch flexible aluminum foil duct that is UL 2158A listed and marked for safe dryer venting. Look for a product that is constructed from heavy duty, fire resistant aluminum foil with a high density, corrosion resistant wire helix. Remember that only ducts 8 feet or less can be UL listed and marked.