Is It OK To Vent Bathroom Fan Into Attic?

Should bathroom exhaust fans be vented outside?

Bathroom vent fans must be vented to the out of doors.

Venting this fan into the attic is simply asking for problems.

The excessive moisture will cause condensation on the roof members, insulation and eventually cause mold.

It is never OK to vent directly into an attic even if the attic itself is vented..

Can you vent a bathroom fan through a wall?

Running any duct through an outside wall should not be done because it will get cold, which would cause condensation. It also would reduce the insulation needed in the wall. Since there is a bathroom below, the lower level may be finished, so it would not be practical to vent downward.

Can you use PVC for bathroom exhaust fan?

If you have just the PVC pipe exposed in the attic, it will get cold and the water vapor in the pipe will condense and run back down the pipe eventually leaking into the bathroom through the exhaust fan. When you go to put the PVC pipe through your roof, make sure to use a high-quality flashing.

Can you oversize a bathroom fan?

Bathroom vent fans are rated for the amount of air they can move, measured in cubic feet per minute, or CFM. Standard fan sizing applies to bathrooms that are 100 square feet or less. The rule of thumb is that you need at least 1 CFM per square foot of room area. … First, it’s a good idea to oversize the fan slightly.

Can I vent an exhaust fan into the attic?

Vent exhaust fans through a roof hood duct already wrapped in insulation at home centers. If you’re tempted to vent your exhaust fan through an existing roof vent, or even vent it into the attic, don’t do it. … The water will condense and drip into the insulation below and perhaps into the house.

Do I need insulated duct for bathroom fan?

If bath fan ducting isn’t properly insulated, the moist air from your house will condense inside the duct. The first step is to head to the attic. You may find that the insulation simply needs to be refastened. … If your ducts are properly insulated, another potential cause of condensation is lack of use.

Can you use dryer vent duct for bathroom fan?

Metal vent ducts: kitchen vent fans require, and good bath vent duct design also uses solid metal ducting, not flexible “dryer vent” material. Solid ductwork has a smoother interior surface that improves airflow, though it is indeed more trouble and a bit more cost to install.

Can two exhaust fans one vent?

But while you can’t have two fans with one vent, you can make one fan and one vent serve two bathrooms. This setup requires an in-line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms (see photo).

Can a bathroom exhaust fan be covered with insulation?

The bathroom exhaust fan can vent out through the wall or up through the roof. The box might be covered with attic insulation. The exhaust fan housing should be covered with an insulated, airtight box. … Caulk or spray foam can be used to seal the box to the ceiling drywall and to seal around the exhaust pipe.

How do you insulate a bathroom fan vent?

Best practice is to wrap the entire duct with R-3 to R-8 insulation, but, if nothing else, you should at least wrap the 6 ft. of duct just inside the termination point, which is where condensation is most likely to happen. Keep the vent low and run the insulation over the duct.

Can you vent bathroom fan to attic?

You should never exhaust the bathroom fan directly into the attic. … It is almost always required by code that the exhaust fans vent on the outside of the home with no air leaks into the interior of the home. Take the time to ensure the bathroom exhaust vent is done properly.

How far can you run a bathroom exhaust fan duct?

eight feetFantech recommends a minimum of eight feet of insulated flex duct between the exhaust inlet register or grille and the fan motor. The company does not cite a maximum exhaust duct length. Maximum vent fan duct lengths are discussed in a reader Q&A below.

How much does it cost to vent a bathroom fan outside?

Cost to Install Bathroom Exhaust Fan Through Roof A bathroom exhaust fan costs between $15 and $300. With labor, expect to pay $60 on the low end and $500 on the high end. This cost depends on the fan price and the project difficulty. You can also redirect air and moisture outside with a roof vent.

What happens if toilet is not vented?

If there is not enough air pressure from the vent in the drain pipes, this water can be lost. … Empty toilet bowls — If toilets do not refill after flushing, or if the level of water in the bowl or tank rises or falls suddenly, it could indicate venting problems in the drains.

What is the code for bathroom ventilation?

the bath should be vented by either a 20 cfm continuous vent fan or a 50 cfm vent fan that is intermittent (or switched). Exhausting of the bath vent fan must indeed be to the building exterior. Exhaust Air from toilet rooms and bathrooms shall not discharge into attic, crawl space or other areas inside building.

How do you vent a bathroom with no outside access?

Options for Fixing Bathroom Ventilation ProblemsInstall a recirculating fan in a half-bath. This type of bath fan doesn’t exhaust air to the exterior. … Reduce noise with an inline fan. … Vent under the floor to get outside. … Build a soffit to hide ductwork. … Install commercial ductwork.

Can plumbing vents terminate in the attic?

Yes, it allows moisture and odors into you attic and it needs to be extended at least 12″ above the adjacent roof. If you cap it, the fixture it comes from will not drain properly. If it’s a drain, then add a vent through the roof too.