A 15 foot long vent with two 90 degree bends 25 feet according to fl building code 504 6.
Dryer vent booster fan installation.
A pressure tap is connected to a tip on the side of the switch.
The airflow through your dryer vent cannot be maintained at the speed necessary to move lint for more than 25 feet.
If a dryer s vent run is over 25 equivalent feet or the dryer is experiencing long drying time your dryer may need a dryer booster fan.
If your dryer vent is longer than 35 feet we recommend that a booster fan is installed to help your system run more efficiently.
Proper airflow is essential for reducing lint build up and keeping your dryer working efficiently.
The electrical to the booster fan is connected in series through a normally open terminal on the switch.
The airflow through your dryer vent cannot be maintained at the speed necessary to move lint for more than 35 feet.
When calculating the length of your vent every 90 degree turn is equal to five feet in length.
This is because moist air cannot effectively exit the dryer and exhaust to the outside bogging down the entire drying process.
Cut the existing duct and attach the booster fan right in line.
Some of the fans have power cords lb and dbf4xl and some can be hardwired.
A professional booster fan installation provides proper airflow throughout the entire system.
When the dryer begins operation positive pressure in the duct causes the switch diaphragm to expand closing the circuit to the booster fan.
Booster fans should be added to any dryer duct exceeding 25 feet in length.
The units will require 120 volts ac.
No other wiring is required since all the controls are built in.
If your dryer uses flexible foil covered or white plastic vent this would be an ideal time to exchange it for the much safer rigid metal ductwork.
I have talked little about these booster fans simply because most homes do not possess them.
According to the booster fan owner s manual the fan should be removed and cleaned every six months.
Locate a spot about that far from the dryer and look for a joint in the rigid duct leading from the dryer.
Booster fan installation if your dryer vent is longer than 25 feet a booster fan may be needed to help your system run more efficiently.