The rule of thumb is that you need
at least 1 CFM per square foot of room area
. To determine the square footage of your bathroom, multiply the length times the width. For example, if your bathroom is 6 feet wide and 9 feet long, its square footage is 54. Therefore, it should have a fan rated for at least 54 CFM.
How many CFM do I need for my bathroom fan?
| Bathroom Size Minimum Ventilation (CFM) Required* | Less than 50 sq. feet 50 CFM | 50-100 sq. feet 1 CFM per sqare foot of floor space | More than 100 sq. feet Add the CFM requirement for each fixture: Toilet 50 CFM Shower 50 CFM Bathtub 50 CFM Jetted tub 100 CFM |
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Can a bathroom fan be too strong?
A
Bathroom fan should not be overpowered
since this will waste energy, create excessive noise and could even pull noxious carbon monoxide into the home. It is OK to get a 20-30 % higher capacity exhaust fan than specified by the CFM calculator. A 20-30% stronger bathroom fan will exhaust the moist air slightly faster.
How big should a bathroom fan be?
In general, choose a fan that
can move 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.
Are all bath fans the same size?
Bathroom fans
are not standard size
. The housing dimensions vary across different models. The duct size is standardized. On most bathroom fans there is a 4 or 6-inch duct.
Is it bad to oversize a bathroom exhaust fan?
Bathroom vent fans are rated for the amount of air they can move, measured in cubic feet per minute, or CFM. … First,
it’s a good idea to oversize the fan slightly
. In our sample 54-square-foot, for example, it’s a good idea to install a 60 CFM fan for good measure.
Is it better to have a higher CFM?
A
higher CFM is always better for your kitchen fan
. You can always run a high CFM hood on lower settings. It provides great ventilation by moving a heavy amount of air per minute.
Why are bathroom fans so weak?
The Dampers Are Stuck
There are two dampers for a bath fan, one at the housing and another where the duct exits the building. If they don’t open easily or open only partly,
airflow will be weak
. Try moving the exterior damper by hand to make sure it opens easily. Clean away any debris that might hinder movement.
What is the strongest bathroom fan?
- Hurricane 12 Inch Inline Exhaust Fan – 1060 CFM.
- Air King High performance – 620 CFM.
- Broan-Nutone l400 – 434 CFM.
- Broan-Nutone 506 – 430 CFM.
- Broan-Nutone 504 – 350 CFM.
- Broan-NuTone L300 – 308 CFM.
- (My Choice) Delta BreezProfessional Pro300 – 300 CFM.
- Panasonic FV-30VQ3 – 290 CFM.
Can I install bathroom fan in Wall?
As a general rule, bathroom exhaust
fans can be installed vertically/on the wall
. Some of these exhaust fans even put that mounting position as an option in the manual. Though you should always consult the manual before making the decision to install it vertically, many can be installed in this position.
How do I know what size bathroom extractor fan I need?
This is calculated by
multiplying length by width by height
. Let’s take an average measurement: 3m long x 2m wide x 2.4m high = 14.4 cubic metres. This means that in order to change the air in that room once an hour, a fan would have an extraction rate of 14m3/h.
What is code for venting a bathroom fan?
Section 1203.4. 2.1 of California’s building code requires all bathrooms with a bathtub, shower, spa or similar fixtures to be ventilated by an exhaust fan. The fan
must be Energy Star-compliant and vented
to the outside.
Where should an exhaust fan be located in a bathroom?
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.
Do electricians install bathroom exhaust fans?
Electricians handle bathroom fan installation
. We recommend hiring a plumber or HVAC specialist if you need new ductwork. But for fan installation and wiring itself, electricians are the ones to call.
What size fan do I need?
| Blade Span Good for Room Size | 29′′ to 36′′ Bathrooms, Breakfast Nooks, Utility Rooms Up to 75 sq. ft | 42′′ to 48′′ Bedrooms, Kitchens, Dining Rooms Up to 175 sq. ft | 52′′ to 56′′ Large Bedrooms, Family Rooms, Media Rooms Up to 350 sq. ft | 60′′ or larger Great Rooms, Other Large Spaces More than 350 sq. ft |
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Can you replace a bathroom fan with one with a light?
Replacing a bathroom vent fan/light combo is an intermediate-level project you can do your own in just two to four
hours
. When taking on this DIY task, be sure to equip yourself with the proper safety gear. Remove the old fan mechanism.
