Where should I put my whole house fan?

Although it really depends on the home, the whole house fan works best when you install it close to the center of your home. The best place is an unobstructed hallway. In order to determine which spot is best in your home, go to your attic and choose the attic joists nearest to the center.

What are the negatives of a whole house fan?





What are the disadvantages of a whole house fan? While a whole house fan is known for saving money on the cooling bill, it can possibly lead to a higher heating bill in the winter, especially for older whole house fans. An older house fan is a perfect escape for the air you are paying to heat in the wintertime.

How many windows should be open with a whole house fan?

Make sure at least one window is open. Opening two or more windows halfway or wider is recommended to allow the fan to do its job. For general cooling, open windows far away from the fan to provide airflow to the whole house. Or, open windows strategically in the areas you want cooled.

How many Whole house fans do I need?

We use a general formula of either 2, 2.5, or 3 CFM, or “Cubic Feet per Minute”, per square foot of living space. 2 CFM would provide a good system, 2.5 CFM would provide a better system, and 3 CFM would provide the best system.

Should you run whole house fan all night?

Actually, it is recommended to run a whole house exhaust fans overnight. This way, you are cooling more than just the air, you are reducing the temperature of your home’s entire structure.

Should you use a whole house fan in the winter?





A whole house fan can provide benefits nearly every day of the year. Not only does it help remove hot air from your home, but it can provide air circulation and improve the overall air quality in every room of your home. Here are some things to know about using the whole house fan in the winter.

Are whole house fans noisy?

Newer whole-house fan models tend to run very quietly and don’t emit the disturbing, loud noises associated with the older style whole-house fans. You can run a newer whole-house fan all night long and still obtain a quiet and peaceful night’s sleep― even if you sleep lightly.

Can whole house fans cause mold?

Many homeowners that have a whole house fan love running them when they get out of the shower to exhaust all that steam and humidity that builds up and can cause mold.

How long does it take a whole house fan to cool a house?

The larger the fan’s capacity, the quicker it will cool the house. The fan should be able to completely exchange all the air in the house every one-to-two minutes. Larger fans will increase comfort and lower the air temperature in the house to near the outdoor temperature in less than one hour.

What size attic fan would an electrician need for a 1500 square foot home?



Attic fan size chart for quick reference

Attic floor area Recommended attic fan size
1000 sq.ft 700 CFM
1500 sq.ft 1050 CFM
2000 sq.ft 1400 CFM
2500 sq.ft 1750 CFM

How many air changes does a whole house fan use per hour?

3 to 6 air changes

Whole house fans should provide houses with 3 to 6 air changes per hour (varies with climate, floor plan, etc.

How do you size a house fan?



1) Determine the total cubic feet of air in the living area in the residence. (Multiply square footage by ceiling height). 2) Divide the fans CFM (cubic foot of air movement per minute) into the total cubic feet of the home to determine the amount of time to perform one air exchange.

How many CFM fan do I need?

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 CFM do I need for 1000 square feet?

Heat and energy recovery ventilators

Total area of home (square feet) Continuous ventilation rate
1,000 square feet 50 CFM
2,000 square feet 100 CFM
3,000 square feet 150 CFM

How is whole house ventilation calculated?



The continuous whole-building ventilation rate is 1 cfm for each 100 ft² of conditioned floor area plus 7.5 cfm for each occupant. The number of occupants is calculated as the number of bedrooms plus one. For example, a three bedroom house is assumed to have four occupants.

What is minimum ventilation?

Minimum ventilation (MV) is the first stage of negative pressure ventilation in a poultry house where the amount of ventilation air exchange is dictated by a time clock setting or timer in the electronic controller, and not by temperature.

How many CFM do I need for 500 square feet?

That’s why we need to divide the total volume by 60; hence 4,800/60 = 80 CFM. Answer: You need an 80 CFM airflow (for 300 sq ft standard room and 2 ACH).
CFM Chart For Common Room Sizes.

Room Size: CFM (At 2 ACH)
How many CFM for a 400 sq ft room? 107 CFM
How many CFM for a 500 sq ft room? 133 CFM

How many CFM do I need for 200 square feet?

Step 1: Calculate Bathroom Size: 20′ x 10′ Bathroom = 200 square feet. Result: You will need a 150 CFM fan for this bathroom.

How many CFM will 12 flex carry?



CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)

Duct Size (Inches) Flex Duct Airflow (CFM)
10 inches 300 CFM
12 inches 480 CFM
14 inches 700 CFM
16 inches 1,000 CFM

How many CFM is 100 square feet?

If you only need the air changed 1 time per hour (ACH = 1), then just . 135 CFM is needed per square foot of space. So, a 100 square foot room would need 13.5 CFM. A 1,000 square foot room would need 135 CFM.