Air exhaust openings shall terminate not less than 3 feet (914 mm) from property lines; 3 feet (914 mm) from operable and nonoperable openings into the building and 10 feet (3048 mm) from mechanical air intakes except where the opening is located 3 feet (914 mm) above the air intake.

How much clearance does an exhaust fan need?

The normal requirement states that a hood and associated ductwork must have an 18″ clearance from combustible materials.

How close should a bathroom fan be to the shower?





Typically a bathroom exhaust fan should be mounted as close to or inside (if rated for tub shower use) to the shower or tub as possible. This will maximize the effectiveness of the unit. Units located in a powder room, should be directly over the toilet.

Where should a bathroom vent fan be located?

You can place the fan directly over the bathtub or shower base, but it’s sufficient to position it anywhere near the bathing area. If the bathroom has both a tub and shower, or a shower and a whirlpool tub, the fan should go somewhere between the two fixtures.

What is code for venting a bathroom fan Ontario?

For bathrooms under 100 square feet, the basic rule is to exhaust a minimum of one cfm (cubic foot per minute) for every square foot of bathroom area. So an 8′ x 10′ bathroom, 80 square feet, would have a minimum airflow requirement of 80 cfm.

Is exhaust fan required in half bath?

A half-bath (normally that means no tub or shower) will not have as great a need for ventilation as a full bath, but it still needs a fan or window. If you install an exhaust fan, you must vent it to the outside.

Can you vent a bathroom fan over a window?





Wall- or window-mount fan

If the bathroom has an exterior wall, an exhaust fan can be mounted on it, eliminating the need for lengthy ducts. It’s also possible to mount an exhaust fan in the window in the same way as an air conditioner.

Can you put an exhaust fan above a shower?

In summary, you actually should install your bathroom exhaust fan in your shower, preferably right over it, where the hot moist air flows directly first. Make sure your electrical circuitry is GFCI protected, and that the fan is rated for shower use.

Can 2 bathroom exhaust fans be vented together?

Well, you can’t! You’d often blow air from one bathroom into the other, and local building inspectors wouldn’t approve it. But while you can’t have two fans with one vent, you can make one fan and one vent serve two bathrooms.

Where should I place my exhaust fan?



Best Venting and Ductwork Locations

  1. Vent kitchen fan directly outside of structure.
  2. Avoid venting between floors or walls.
  3. Keep ductwork as straight and smooth as possible.
  4. Minimize duct bending to avoid crushing or dents.
  5. Use the maximum diameter duct to fit exhaust fan.
  6. Do not vent into attic or crawlspace.

Is it OK to vent bathroom fan into soffit?

A bathroom fan can be vented through soffit so that the warm air from the bathroom comes out through it and goes outside. However, It is important to keep in mind it can not be vented into the soffit, as this will lead moisture back into the attic.

Is it OK to vent a bathroom exhaust fan into the attic?



No, you should not vent a bathroom fan directly into an attic. The problem with venting into the attic is that the moisture-rich air may form droplets on the wood sheathing, insulation, rafters, and ceiling joists, leading to mold growth.

How long can a bathroom vent duct be?

Generally a 4 inch flex duct can carry a fan exhaust for up to 25 ft. Most codes require that.

Can flex duct be used for bathroom fan?

Flexible duct is perfectly acceptable for a bathroom fan.

Does a bathroom vent need to be vented outside?

Bathroom fan installation requires outside ventilation. If the fan isn’t accessible through an attic, you’ll need to vent through a sidewall of your house. These types of ducts and vents are typically installed when the house is built. If you don’t have a duct leading to a sidewall vent, call a professional for help.

Can you have too much CFM in bathroom?



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.

How do I know if my bathroom fan is strong enough?

A simple way to test your fan’s suction is to take a single square of toilet paper and place it along the fan vent while the fan is running. If the fan holds up the toilet paper, then the fan is working properly.

Is 80 CFM enough for bathroom?

Choose a fan that can ventilate at least 1 CFM per square foot of room. So, for an 80 square foot bathroom, select an 80 CFM fan. For bathrooms 50 square feet and smaller, it’s recommended you purchase a bath fan designed for small rooms. In other words, choose under 79 CFM bath fans.

How many Sones is a quiet bathroom fan?

Typical bath fans range anywhere from <0.3 sones to 6.0 sones. Below is a chart detailing what sound level you can expect out of a certain sone level: <0.3 sones: This is the lowest possible sone rating for a ventilation fan. At <0.3 sones, you won’t even know the fan is running (maybe like my hotel experience?)

Is 3 sones loud for a bathroom fan?



Sones are used to measure noise, such as fans, which includes kitchen fans, bathroom fans, and those found in your range hood. One sone is equal to about 1,000 Hz with a sound level about 40 decibels above a normal reference level.
Defining the Sones Rating.

Sones Decibels
1 28
2 37.99
3 43.84
4 47.99

How many CFM do I need for my bathroom exhaust?

Ventilation rates based upon eight air changes per hour are generally suggested. For most bathrooms this works out to one CFM per square foot of bathroom area. For example, a 7′ x 10′ bathroom would require a 70 CFM fan. A 50 CFM rating is recommended as a minimum for bathrooms 50 sq.