Master Flow 4500 CFM 24 in. Direct Drive Whole House Fan with Shutter-WHFS24M - The Home Depot

Master Flow

Model # WHFS24M

Internet # 100018252

Store SKU # 432659

4500 CFM 24 in. Direct Drive Whole House Fan with Shutter

Master Flow 4500 CFM 24 in. Direct Drive Whole House Fan with Shutter

This item has been discontinued.
The Home Depot no longer carries this specific product.

$245.00 / each
  • 10 Year Parts Limited Warranty; 5 Year Labor Limited Warranty
  • Direct Drive Motor
  • Maximum house size for optimum performance: 2500 sq. ft.


Model # WHFS24M

Internet # 100018252

Store SKU # 432659

Store SO SKU # 813317

The Master Flow 4500 CFM 24 in. Direct Drive Whole-House Fan is a smart energy saver for any home in a climate where air conditioning costs are a concern. It will allow you to beat the heat by forcing hot air out of your home through your attic space while bringing in cooler outside air through your windows and doors. A Whole House Fan is an important part of a complete home ventilating system! Unit comes with a white shutter and features a low-vibration direct-drive mechanism for reliable performance. A minimum 1100 sq. ft. of attic space with a minimum of 1008 sq. in. of net free area attic exhaust is required for proper operation.

  • Moves air at a rate of up to 4500 CFMs
  • ¼ HP permanent split capacitor motor
  • Direct Drive motor design
  • 2-speed pull chain switch control
  • Includes automatic ceiling shutter in white
  • Can be installed with no joist cutting
  • UL/UL Canada listed


Assembled Depth (in.)  27.75 in  Assembled Height (in.)  5 in 
Assembled Width (in.)  27.75 in  Cut-Out Left to Right Width (in.)  27.25 in 
Product Depth (in.)  31.5  Product Height (in.) 
Product Width (in.)  30.5 
Amperage (amps)  2.3  Color Family  Metallic 
Color/Finish Family  White  Material  Galvanized Steel 
Product Weight (lb.)  36 lb  Returnable  90-Day 
Voltage (volts)  120 
Warranty / Certifications
Manufacturer Warranty  10-year Parts Limited Warranty 5-year Labor Limited Warranty 


Rated 3.7 out of 5 by 69 reviewers.
Rated 5.0 out of 5.0 by Works GREAT!!! Although I have only had this fan installed for several days, I LOVE it! I decided to go with the 24" fan because my house is less than 2200 sq. ft. and I was told that if there wasn't adequate ventilation, the 30" fan would/could make excessive noise. I'm not sure if people have difficulty installing the fan, but the way I did the install makes the fan seem "quiet". The fan noise is very comparable to a traditional box fan. I truly do not mind the noise it makes. I also put the fan on a 60 min. max timer. What I have been doing is setting the timer anywhere from 30-40 minutes, with a couple of windows open down stairs and one or two open up stairs. This cools the house down extremely fast. I am so glad I decided to put a whole house fan in our home. You should do it too! You won't be sorry! May 4, 2014
Rated 5.0 out of 5.0 by Good fan I didn't follow the directions, This is what I did and the fan is quiet. My house is 2300 sqft and it pulls the air thru nicely. I open the windows about an inch in the bedrooms and other rooms I want air to come in from the outside. My attic has vents on both ends of the house and affords plenty of exit space for the fan exhaust air. I got these Ideas off the internet and found them to be absolutely correct. First I mounted the fan in my attached garage ceiling. The fan will pull air from your home and into your attached garage ceiling. You don't have to mount it in the house. You will not get that central fan noise in the house that way. We have a screen door in the kitchen that goes to the garage. The air flows out thru the screen door. The next thing I did was to build a box for the fan to sit in on top of the ceiling joists. I cut the center joist and boxed it in. Then built a frame to hold the fan on top of the joists. I cut lengths of pipe insulation to fit on the fan wood frame. The glue on the insulation seam holds the insulation on the frame.$1.79 each for 2 insulation tubes at HD. The frame, is snug to the insulation but not tight. Hence when the fan runs, it is not vibrating on wood to wood contact. All you hear is the fan blade turning like you would any fan. There is a pull chain to turn it on and off. It is a 2 speed fan. I run it on high. I used the same size wood the ceiling joist were made of, to box in the joists where I cut one out. I used 2x4 s to make the box on top of the joists. I used a sawzall to cut the sheetrock, and the center joist. If you bridge across the top of your joists before you cut the center joist, you will not get any sag from the two ends of the cut joist. All will be strong after you box them in. I attached a wire and a plug on the fan wire to power the fan. I plugged it in to a receptacle in the attic. The pull chain is right outside the kitchen door in the garage. August 17, 2013
Rated 5.0 out of 5.0 by This fan really works great. You can feel the air stream by you and it cools down the house in no time! It is amazing how many people do not know what a Whole House Fan is. Even contractors. It is a very efficient way to replace the air in your house and attic just by running this fan for about 15 minutes once the air outside is cooler than the air in your house. This fan was not the biggest, but it seems to be built really well. I am very impressed! August 20, 2013
Rated 5.0 out of 5.0 by 4star becomes 5star almost 4 years ago i wrote the lengthy (and helpful) product installation & description review regarding this whole house fan.--- Indy 2010 whole house fan Well the fan is still problem free and fantastic for spring through fall use. Wonderful breezes are pulled through the open windows/doors-- like you are riding a bike while you sit on the couch or at the table. We have actually become more users of the house fan than our AC -- the abundant, and constant, fresh air breeze beats the AC. But sometimes... the AC is called upon, but not like it used to be. We run this thing as the primary cooling device, many hours straight, no problems. Great "white noise" to sleep through. Periodic cleaning of the louvered vents and about once a year I clean the fan motor and blades, check the blade for tight/secure, no slippage. Do yourself a favor, save money and stay cool with this thing. February 18, 2014
Rated 3.0 out of 5.0 by Blows a lot of air, noisy This fan has worked fine for me for over 10 years. It blows a lot of air, but I wish it were quieter. When you are close to it, you can't hear anything else. The motor finally burned out a winding. The exact replacement motor is only available from the manufacturer of the fan, which is a big disadvantage. Replacement parts should be generic and easily available, otherwise, the fan blows no air at all. If I was starting from scratch, I would look for a quieter fan with a motor that is easy to oil and replace. This is the second one I have bought and installed. The bottom line is that it blows a lot of air, lasted me over 10 years of intense use every summer, and the price was reasonable, but you have to accept that it is very noisy. May 21, 2012
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