I used insulated flex ducting like below for my bath vents. If installing vent piping is not feasible installing a duct-free vent fan is an option.
Bathroom vent fans work by.
Bathroom Exhaust Fan Venting Options. There are really only three venting options. Venting a bathroom fan into the attic or ceiling space without a vent pipe to the exterior can cause mold or mildew to form on the ceiling or in the attic. Bathrooms Must Have Windows When this section is adopted by a community it essentially says that for venting purposes bathrooms must have windows that open.
A secondary reason for venting outside is to improve the air quality inside your home. If you have an old bathroom with only a window as a source of ventilation it might still be a good idea to provide extra ventilation. When natural ventilation requirements 3 sq ft of windows 50 operable cant be met the bath should be vented by either a 20 cfm continuous vent fan or a 50 cfm vent fan that is intermittent or switched.
Try to keep it flat or sloping toward the outside to avoid condensation pockets. Exhausting of the bath vent fan must indeed be to the building exterior. The code reads that the window must have aggregate glazing areaof not less than 3 square feet 03 m 2 one-half of which must be openable.
By fabricating bath fan duct runs from rigid metal or PVC plastic youll get the best long-term performance from your fan. Run a rigid vent from the gable wall to a point near your install and use a 2 piece of flex duct to connect the fan to the rigid vent. 1042020 Look for a fan that can be shuttered for storms or say when flying ants are hatching outside.
It can crush or tear easily which will impede air flow. M15072 Exhaust air from bathrooms and toilet rooms shall not discharge into an attic crawl space or other areas inside the building. Installing a window if you can is the easiest of venting.
6242019 It is pretty much standard for bathroom exhaust fans to meet these requirements though it should be stated in the product description of your fan. You have several options when considering bathroom. Wall fans are more work and higher cost than the ductless version but theyre highly effective for expelling moisture and odors.
Larger fans of over 50 CFM are usually recommended for larger bathrooms. No matter the location of the bathroom you can vent the exhaust fan through the wall. Typical bathroom ventilation codes such as the 2006 IRC specify that a bathroom toilet vent fan must provide 20 cfm if the fan runs continuously and 50 cfm if the fan runs intermittently presumably switched on and off manually or by a timer.
Avoid using inexpensive flexible duct Flexduct to vent a bathroom fan. 5122020 Use metal or PVC for ductwork. No you cannot vent the bathroom exhaust fan into the soffit vents.
Sizing a bathroom fan can be somewhat tricky as the information out there is all over the place. A smaller bathroom of less than 100 square feet may only need one 50 CFM fan used intermittently not continuously. 4122013 M15011 Air shall not be exhausted into an attic soffit ridge vent or crawl space.
Im not familiar with a code that requires rigid ducting for bathroom fans. An exhaust fan will help move unpleasant odors and potentially irritating cleaning chemical fragrances to the outdoors where they wont bother you or your guests. If you vent the bathroom exhaust fan to close to the soffit vents which are vented plates under your homes outer edge and roof your home the air can be sucked right back into the attic from the soffit.
Just open the window and let nature give you a hand. Check before you choose it. The size of the fan that you install will be determined by the size of your bathroom.
Bathroom Exhaust Fan Venting Options. How to Vent a Bath Fan Through the Roof This Old House – YouTube. 2182010 There arent many options for routing an exhaust fan to the outside of the house.
The flex duct makes the bends easy dont kink it and allows the fan to be repaired from below in the future.