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.
The room's square footage will tell you what the CFM should be (12 x 12 = 144).
1 Answer 1 You can certainly go with an 80 cfm unit, the only drawback being additional noise (in general the more powerful the unit the louder they are). This can be remedied by using a high-quality unit designed to be quieter. You certainly can (and should IMO) use regular duct pipe in lieu of flex, wherever you can.
This can cause warped cabinetry, foggy mirrors, and mould or mildew growth. A fan that is too big can cause a bathroom to be cold and noisy. This is why calculating the correct CFM is important.
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. For medium-sized bathrooms, use 80 to 99 CFM bath fans. For large bathrooms that are over 100 square feet but under 150 square feet, use over 100 CFM bath fans.
On the other hand, if your CFM is too high for your room size, it can cause ventilation problems. Too much air results in too little ventilation, which in turn causes high humidity. The excess moisture in the air can then lead to mold and mildew, as well as other problems.
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.
Finally, the average bathroom fan with a basic light fixture will use 36 watts of energy. Depending on which manufacturer you go with, you could see a watt usage of 10 to 50. The bottom line, the less you use the fan, the less electricity will be consumed.
We recommend at least an 80 CFM for most bathrooms but a 100/110 for a larger master bathroom. This will help move the moisture out of the bathroom and reduce the risk of mold.
When sizing a vent fan, a factor to consider is duct size and length. Most 50 CFM fans will run well with a 4-inch round duct. But as you get up into the higher CFM fans, duct size will have to be increased to a 5- or 6-inch round duct.
Some of the issues come from the fact that they are installed in rooms that are bigger than their intended use. In an ideal situation (which never exists) a 50 CFM fan is good for a room about 50 square feet. In a real-world setting, it is probably closer to being able to handle a room between 35 and 40 square feet.
One cfm is needed per square foot (1 cfm/sq ft) of floor area. This is the average air quantity required for a room or an entire building. This number is based upon an averaged heat load calculation for comfort cooling.
What size ceiling fan do I need for a 12x12 room? A 12x12 room would have an area of 144 square feet, which means you'll need a large ceiling fan between 36 and 50 inches. For more help, see "Choose the Right Ceiling Fan for Your Space" above.
Excessive Usage Can lead to fire hazards and other problems
The fumes from the combustion process can be explosive, so proper ventilation is necessary. Bathroom exhaust fans should be used only when needed. If you have a high-capacity bathroom fan, you may use it multiple times each day.
Heating and cooling: 45-50%
The largest electricity consumer in the average household is your heating and cooling appliance. By a long shot. Central air conditioners and heaters use tons of energy in order to keep your home set to the right temperature.
Circuit for Lighting and Fan
Each bathroom must have the electrical wiring and capacity for a light and an exhaust fan, at minimum. Fans are used to ventilate the bathroom area. This circuit should be a 20-amp circuit in order to accommodate both features.
The higher the CFM the more air it can move, so an 80 CFM fan and a 150 CFM fan will both work, but one will get the job done in about half of the time. Approximately. A good way to select the CFM you need is to use the square footage of the area it serves. So an 8 x 10 bathroom would get an 80 CFM.
Performance: The higher the CFM, the more powerful the range hood is at removing smoke, steam, and odors. A good range hood CFM depends on the size of your kitchen, the type of stove, and how frequently and intensely you cook. Generally, for every foot of your range's width, you need 100 CFM.
If you cook every day or frequently cook for larger groups of people, it's best to choose more CFM.
Yes, your bathroom fan can be too big. A bathroom exhaust fan that is much too large for the area will only increase your energy bill, fill your space with cold air in the winters, and ultimately, not perform its job effectively.
Yes, provided both fans are fairly equally powered and will operate at the same time. You obviously don't want one fan significantly more powerful than t'other as it could - theoretically - send its contents out the other fan.