4" Soffit Vent for Bathroom Fan

No, our bathroom soffit vent is not intended for dryer vents and can cause serious issues. The screen on the front of the soffit vent will collect lint and cause the vent to clog.

We are working to create a dryer exhaust version.

We can't recommend using 1 soffit vent for multiple bath fans since there would be more details involved in the system design.

• Where the two flows come together is important. It should be as close to the vent as possible.
• How the two flows come together is next. They should connect with an inverted "Y" to minimize the backflow potential from one fan into the other.
• Both flows should be equipped with backflow preventers, preferably just before the "Y" but it may also be possible that each exhaust fan is equipped with a backflow preventer.
• Finally, and very importantly, the total CFM of both fans must not exceed the rated cfm capacity (150) of the soffit vent.

Assuming the above are addressed by a professional, then this type of installation should be OK.

No, this is a common misconception. Soffit vents should not discharge air under the soffit. That incorrect venting risks putting the health of your home and family at risk.

Our soffit vent's design correctly displaces moist bathroom air away from the home and helps prevent the following issues that other vents can cause:

• Water and roof damage
• Higher heating and air conditioning costs
• Increased moisture in the attic which can cause mold and rafter degradation
• Early deterioration of roof shingles
• Indoor air quality issues that can impact health

Unlike other soffit vents, our patented vent:

1. Is the only bath fan soffit vent that can accurately claim that it moves the exhausted air away from the house, preventing entry into the attic via the soffit.
2. Makes venting bath fans through the soffit the ideal method of venting. Our soffit vent eliminates roof penetrations and long exhaust ducts to a gable wall. Homeowners and builders can now vent bath fans without risking moisture damage and mold growth in the attic.
3. Is the only soffit vent approved in the state of New Jersey* for installations without the need for draft-blocking 4 feet** of soffit on either side.

*Approved by NJ BPU Comfort Partners Subcommittee in October 2023.
**Always check local building regulations before installation.

You should use our soffit vent over a roof vent because:

• Roof venting bath fans increase the risk of roof leaks, water damage, and mold growth. Roof penetrations are the number one cause of roofing system failures.
• Venting through the soffit is the least invasive and lowest-risk option – having a minimal impact on the roof and siding systems. Keep in mind this is only true if you use our soffit vent given its patented design.
• Minimizing roof penetrations improves curb appeal by streamlining the design of your roof.

Using our soffit vent for bathroom fans is better than using a gable wall vent because:

• Gable venting bath fans often require lengthy exhaust ducts, increasing the risk of condensation in the duct, potentially causing moisture damage and mold growth.
• Lengthy exhaust ducts decrease fan pushing power. Gable venting is not ideal for low-speed fans because the fan cannot push the exhausted air out of the house. Venting through the soffit using our soffit vent uses a shorter exhaust duct system because most bathrooms are on an exterior wall directly below the soffit. Shorter exhaust systems promote the removal of the exhausted air.
• Gable venting exhaust ducts are exposed to attic temperature fluctuations, which can promote condensation, moisture damage, and mold growth. Conversely, using the PreVent-It soffit vent to vent through the soffit positions the exhaust duct system under the attic insulation, protecting the duct from attic temperature fluctuations.

Our 4 inch soffit vent has these main features:

• Patented design making it the only bath fan soffit vent that removes the exhausted air away from the home, preventing air entrance into the attic
• Made of durable resin plastic that is UV-resistant to help it maintain the original color
• Easy to install
• Made in the USA
• 1 year limited warranty

Leading builders in the U.S. who guarantee their homes and roofs have told us this is a game changer for them. Some spend an average of $6K over the lifetime of their home warranties (20 years) on roof leaks caused by roof penetrations. Bath fan venting is a common roof penetration, and each fan requires its own penetration. Builders are eager to eliminate as many roof penetrations as possible to avoid costly remediation and repairs caused by penetrations – or holes – in the roof.

• Eliminating roof penetrations saves money on costly remediation and repairs.
• Venting through the soffit using the PreVent-It soffit vent promotes structural integrity and is the least invasive method of venting.
• The PreVent-It soffit vent has curb appeal, blending into the entire soffit and roofing system.
• Our soffit vent offers peace of mind, as it is the only soffit vent designed to remove the exhausted air away from the house – achieving up to 95%+ displacement out of the soffit’s passive air stream.

The PreVent-It soffit vent was created by a remediation expert that knows her business. When asked to remediate exhaust issues she couldn’t find a viable solution, so she created one.

She kept seeing the same problems caused by venting bath fans through the soffit using conventional soffit vents – moisture damage and mold growth. Despite the problems observed by venting bath fans through the soffit, she believed venting through the soffit was still the best option to vent if the exhausted air was “thrown” away from the soffit’s passive air stream

PreVent-It's soffit vent meets its goals: proper and thorough removal of the exhausted air away from the house, solving the problem that all other soffit vents perpetuate. Now, venting through the soffit is ideal for builders and homeowners.

Consumers have told us:

• It’s easy to install.
• I don’t have to cut through my roof!
• I don’t have to cut through my gable wall!
• It blends nicely with the outside of my house.
• I don’t have to worry about the exhaust air going into my attic.
• I can use it on my low-power fan
• The front of the vent is removable in case I ever need to clean it.

You do not need to put screws in the 2 holes nearest the removable screen. Use the 4 provided screws to attach it to the soffit as noted in step 3 of our installation instructions.