We're doing a home addition to gain a laundry room in Orlando. I'm worried about moisture and plan on putting in a decent backdraft damper. How much should I budget for the duct work and damper unit? Are booster exhaust fans really necessary to make sure the damper opens properly?
Kevin Y. ~ Orlando, Florida
I would not worry too much about moisture coming in through your dryer vent. I would worry more about making sure that your dryer vent gets the moisture out of your home from the clothes drying process. A back draft damper will only prevent air from coming in from the outside. I generally upgrade the dryer one-way flapper because cheap ones can rattle in the wind and can be an annoyance. Cheap or expensive, I have not been able to tell much of a difference as far as functionality. The California code for a dryer vent is that it has to be smooth metal 4" pipe, no longer than 14 feet, with no more than two 90-degree bends. If you must install more than 2, 90-degree bends, and then you must shorten the overall length by 2 feet for each additional 90. When these guidelines are followed, there is no need for a duct assist fan. Since you are doing this work in Orlando, not in California, I would check with the local building department and find out what is required for dryer vents in your city. If the walls are still open, and you are less than 14 feet in distance from an exterior wall, I would budget only a couple hundred dollars to install he ducting. It is also a good idea to know specifically where the ductwork attaches to the back, side, or bottom of the dryer so that you can rough in the ducting as close to the attachment point as possible. Good luck!