QA

Question: How To Size A Whole 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 do I need for a whole house fan?

Recommended whole house fans and their sizes Area (Sq.ft) Recommended CFM Recommended models 1000 2000 – 3000 1500 3000 – 4500 Cool Attic fan 2000 4000 – 6000 QuietCool CL-6000 2500 5000 – 7500 Cool Attic CX302DDWT.

How many CFM do I need per square foot?

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.

How many CFM should a house have?

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.

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 CFM do I need for a 3000 sq ft house?

800 CFM Room Size: CFM (At 2 ACH) How many CFM for a 2500 sq ft house? 667 CFM How many CFM for a 3000 sq ft house? 800 CFM.

Does a whole house fan need a dedicated circuit?

You only need an individual branch circuit (what’s called “dedicated” in the trade) in specific scenarios. Kitchens and similar areas need a small appliance outlet dedication.

What is the CFM formula?

CFM = (fpm * area), where fpm is the feet per minute. To find the cubic feet per minute, substitute the FPM value with the area after the area is squared.

How many CFM do I need for 1200 square feet?

The result is as follows: 1200 cfm/2000 sq. ft. = . 60 cfm per square foot.

How many CFM is 100 square feet?

Fan Sizing for Bathrooms Under 100 SQ. FT. The standard rule for bathrooms 100 square feet or smaller is one CFM per square foot of the bathroom. To find the square footage multiply the length of the bathroom by the width.

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.

How do you size a quiet cool whole house fan?

Simply measure the width and length, in inches, multiply them together; divide by 144, and that is your gross free vent area in square feet. Then, simply deduct 25% off that number to get the net free vent area, which accounts for any air restrictions through the vent.

How do you size a ventilation fan?

Calculation: Area of the Room=Length x Width x Height. Area of the Room=10 x 15 x 10 =1500 Cub. Foot. From the table Air Changing Rate (ACH) for Bathroom = 8 Times/Hour. Size of Ventilation Fan = (Area of Room x ACH ) / 60. Size of Ventilation Fan = (1500 x 8 ) / 60 = 200 CFM. Size of Ventilation Fan = 200 CFM.

What’s the difference between an attic fan and a whole house fan?

Attic fans are quite different. They’re installed up on a roof or through an exterior wall up in an attic. Whole-house fans need windows and doors open and attic fans need lots of soffit vents to suck cooler outdoor air up into the hot attic. Without this open space, the fans will not move much air.

How much does it cost to install a whole house fan?

Cost to Install a Whole House Fan To add a whole house fan, homeowners pay between $1,250 and $1,830 on average. On the low end, you can expect to pay between $700 and $950 including labor. On the high end, the project can cost $2,000 to $2,750 including labor.

How do I calculate attic ventilation for whole house fan?

You need a minimum of 1 square foot of attic air venting for each 750 CFM of air flow. If you need 6,000 CFM of air flow through your house, divide 6,000 by 750 to get a minimum 8 square feet of attic venting. That translates to one attic vent 3 feet by 3 feet, or two attic vents, each 1 ½ feet by 1 ½ feet.

Is a higher CFM better?

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. If you cook often or enjoy Asian cooking, a high powered fan is essential to keep grease out of your kitchen exhaust system.

How many CFM is a 3.5 ton AC?

How many cfm for 1 – 5 ton ac unit ? Cooling Capacity CFM (Airflow) How many CFM is a 2 ton ac unit? 700 – 800 CFM How many CFM is a 2.5 ton ac unit? 875 – 1000 CFM How many CFM is a 3 ton ac unit? 1050 – 1200 CFM How many CFM is a 3.5 ton ac unit? 1225 – 1400 CFM.

How many CFM is a 4 inch duct?

Reviewing the chart, a 4” pipe will convey 395 CFM at 4500 FPM. This means that a 4” pick-up on a machine will use 395 CFM from the filtering system; or, if you know that a machine will require approximately 400 CFM to remove the waste, you should use a 4” pipe for that purpose.

How many amps does a whole house fan pull?

Depending on their size and construction, floor fans draw anywhere from 0.3 amps to around 3 amps. This significant range coincides with a large range of power and price. Usually, you can find the amps required for a specific fan on the label or within the sale information.

How many amps does a whole house fan use?

An attic fan needs up to 5 Amps of service. Up to 10 electrical boxes can be handled by a standard 15-amp home circuit.

How many amps does a house fan pull?

The majority of modern ceiling fans use less than an amp, averaging between 0.5 and 1 amp, depending on the model and the setting. One amp drawn by a ceiling fan is equivalent to about 120 watts. Low settings use less amperage while higher settings use more.