The Master Flow 4,500 CFM Power Whole-House Fan is designed for houses larger than 1,000 sq. ft. It works with or without central ducting to cool your home by pulling fresh air in from outside and pushing warm air up and out into the attic. It has a 24 in. shutter and features a low-vibration direct-drive mechanism for quiet, reliable performance.
(55 reviews) 55
74%of customersrecommend this product40 of 54reviews
Rating Breakdown55 reviews
74%of customersrecommend this product40 of 54reviews
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.
Pros: Easy to Use, Performs Well, Easy to Install, Quiet, Good Size & Weight, Seals Well, Good Shape, Great Value, Easy to Clean, High Quality, Economical, Light Weight
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Whole house fan mounted in Garage will vent the house if your garage is attached to the house.
12out of12found this review helpful.
Review 2 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
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.
Pros: Performs Well, Great Value, Reliable
3out of3found this review helpful.
Review 3 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
from El Sobrante, CA
Age Range:45 to 54
Home Improvement Profile:Other
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!
Pros: Easy to Use, Performs Well, Easy to Install, Easy to Work With, Good Shape, Great Value, High Quality, Economical, Reliable
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3out of3found this review helpful.
Review 4 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
I have owned several homes with whole house fans ... this is the loudest one I have heard. However, if you have a hallway to the garage or other out of the way location, it is not too bad. If you go with the standard "over joist" mount, plan on cutting up two two by fours to build a base around the joist, and if you have blown in insulation, plan to cut up two six foot one by tens to build a box that extends above the fan to hold back the insulation. It takes only a few minutes to draw cool air through the entire house. Only wish is that the low speed would be lower. Even low still creates quite a breeze through the house!
34out of34found this review helpful.
Review 5 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
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.
29out of29found this review helpful.
Review 6 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
*Tip* I grabbed a roll of wide camper mounting foam tape to put between the fan and the frame, suppose to make it less noisy
I special ordered the belt driven fan and it arrived in 2 weeks. The measuring, cutting, fitting, mounting wasn't to bad. Wiring is confusing (I'm not an electrician) and I had to make a new hole in the wall for switches and finally after it was all wired up, the motor was dead. I thought maybe the belt tension or wiring but nope dead motor. I returned the belt driven fan and had to grab this direct drive fan off the shelf because I didnt want to wait 2 more weeks with a giant hole in the ceiling. Having had both in the same weekend
Reasons to go with the direct drive fan -Includes a shutter template to cut out the ceiling. With the belt driven fan, I had to use long sticks and a square and it came out a little crooked (you know, you don't cut straight either) -The direct drive shutter is square (a little bigger), the belt driven shutter is a smaller rectangle. It would make a difference when replacing -This shutter is nicer, shinier, better flaps and a bit more solid -Includes a very nice joist-in mounting bracket/set up -It's easier to assemble (2 minutes to flip the fan blade and tighten) vs belt driven remove the motor, put it on right, adjust belt and re-adjust -It's lighter which makes it easier to lift and get it up there -The wiring is so much easier, no holes in the walls or fishing out wires. It is just 2 wires and a pull chain for the switch
Reasons to go with the belt driven fan -It's cheaper -It has 4 blades on the fan vs 3 on the direct drive so maybe better air flow -The belt driven is suppose to be quieter. I can't say because mine didn't turn on but I think they are all noisy, not motor noise. It's a big fast moving fan moving a lot of air noise. Even my 20" box fan on high is noisy
Starting from scratch I would go with the direct drive. Sometimes stuff is on the shelf because they are better and easier to put in
Pros: Easy to Use, Easy to Install, Easy to Work With, Straight, Good Shape, Great Value, High Quality, Light Weight
0out of0found this review helpful.
Review 7 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
Home Depot is fine. The unit however, is very loud, even on low fan speed. It was unexpected that the fan noise would be this loud since I was replacing with an identical unit (the old unit: the low fan speed noise level was acceptable - the bearings wore out, thus the replacement). Once I/you install the replacement unit and discover the noise/decible level it's too late to return without severe effort: time, sweat, reinstallation cost, etc.
22out of22found this review helpful.
Review 8 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
Fan was relatively easy to install, all parts seem to be of good quality. Installed an RF remote outlet (SVAT WRC101) and key fob for easy on / off. This works great from anywhere in the house. Fan is quiet but has the sound of rushing air, would definitely recommend this fan.
0out of0found this review helpful.
Review 9 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
I spent a good bit of time installing this fan in the house I just bought. Upon completion of the project I was ready to test the new fan. It works is the best I can say about it. I have a whole house fan in my previous home and wouldn't think of not having one in this house. After turning this one on I was very disappointed in noise level. I walked outside to the street and could still hear it. I won't buy another of this brand. It's loud, what? It's Loud, what? IT'S LOUD.
42out of45found this review helpful.
Review 10 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
The fan is good for the cost with a solid motor and a decently built frame. When installing additional joist support the louvre cutout is bigger than the fan frame so a complete flush frame on which the fan can sit is impossible. However, the provided plastic pieces bridge the gap well to channel airflow. My only complaint is the switch was pretty cheap and broke after 1 day of use (would not reset and allow me to shut off the fan - it stuck). Company has offered to send out another one in 5-7 days. Brother-in-law has the same fan and also had the provided chain switch break in the first week. Definitely look into constructing some kind of insulation box for summer and winter since it is literally a 30" hole in your ceiling that is only insulated by some thin plastic flaps.
16out of16found this review helpful.
Review 11 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
This whole house fan is the first one I have installed. The job came out perfect. I first read the instructions three times. I didn't think the instructions were worthless like some reviews said. Maybe they have updated them. If anything, they were very detailed and you had to avoid the parts that didn't concern your particular type of install.
This unit seems to be designed to be placed on one of the joists. The middle of the fan and shutter has a notch so it can be placed directly on to the joist. Once I found a place for the fan, I found that the joists next to the joist I had placed the fan on were too far to hold the edges of the fan. I had to cut some 2X4's to make up the difference. After adding the 2X4's, I placed the shutter template on the attic floor and traced around it. I cut the hole for the shutter from inside of the attic. Once the shutter hole was done I installed the fan and then the shutter.
I don't believe this fan is made to be ran all day or evening. This fan will cool my whole 2500 foot house in less than 20 minutes depending on the temperature of the air outside. I just open a few windows on the first floor and turn on the fan. You can feel the cool air coming in from outside. It also pushes all of the hot air out of the attic.
As far as the noise, the noise is comparable to the amount of air the fan moves. If you look at one of those slow turning fans that are usually installed in a factory that are very quiet, you will also find they have to be quite large to move any air. This fan is quite small for the amount of air it moves. It will be louder because of the amount of air being moved. I can put up with noise for 20 minutes to get my house cooled down. But I really don't think this fan is loud. If you are married, you will fine this fan is quieter then a wife (or husband). Just kidding !!!
After about four hours, the fan was installed and ready for use. I love this fan. It is much cheaper then using the central air conditioner.
32out of33found this review helpful.
Review 12 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
For the cost this fan does a great job. Direct drive is typically a bit noisier than belt drive and definately noisier than in line fans. However, in line fans are about four times the cost. The consistent noise easily becomes white noise. Installation is not difficult but is not for the weak! You are cutting a hole in your ceiling and need to do some electrical wiring. I installed mine in the attic access so I did not mount it on all sides. I built out a frame that the fan sits on and mounted it with hinges so I can simply push it up to access the attic. I added weather stripping to seal it and the back pressure when the fan is on really keeps it tight. Instead of the pull switch, I added a dual on/off timer switch for more control. Typically, I want the fan to go off once we fall asleep because it can get too cold if it stays on all night in So. California. Something else to remember is that you do not want to open all the windows in your house. A few strategic windows across the house works much better. It will create a breeze in the house. Bottom line is that venting the attic alone will help cool the house and a whole house fan will draw air through your house creating a nice breeze but the temperature of the air is still up to mother nature! Hope it helps.
15out of15found this review helpful.
Review 13 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
24 in Master Flow direct drive WHF installed this model in early July 2010, Indianapolis. Blower went out on my furnace (18 yrs), so no AC. This was a VERY HOT SUMMER, record breaking "most above 90 degree" days, most consecutive above 90 days in history. Hot, humid, miserable.
Had 1 helper, neither of us are trade educated but both are pretty handy. A 60 and 40+ year old doing the work here. Only "special tool" we used was a saws-all (reciprocating saw). A circular saw would work but not as easily. I think you can rent a saws-all Standard tools: drills, chalk-line, tape measure, ratchet or socket wrench, utility knife, dry wall saw. If possible keep a "set of tools" with each worker (attic man and inside house man). Get some knee pads if you don't own a pair. You will both want them if you need to work up on the roof as we did.. and gloves.
Understand that the real "cooling action" from this fan takes place @ night. I would open windows, turn on the fan about 6-8 pm. The inside house temps were usually about 82-85 degrees at this time on bad/worst days. With the hottest hours of the day past, open up and draw fresh air in. I run the fan through the eve/night and then shut the fan off, close all the windows/blinds-curtains and doors about 7-9 am. Just seal the house up. The inside temps would usually/only be 74-76 on the worst days. Just depends on how cool it during the night. Then the morning/daytime heat returns and the house slowly heats back up again. Keep the house closed, keep as much of the 90 degree heat from coming inside That's how this thing works. Cool off at night, close up the house, locking the cool air in and go to work. If you stay home I ran a box fan just to move air around inside the house and waited. It was not bad at all, 77-81 degrees well into the afternoon, 2-3 pm. This is the bad days, of which there were way too many this summer. With normal night temps the house gets even cooler, low/mid 60's, so the house stays VERY NICE AND COOL. When the temps went into the hi 50's one night we(somebody) had to shut the fan down... it was too cold for my wife.
But remember It is not "air conditioning".
My electric bill usually runs $100++/- in the summer (gas water/heat/dryer). Using the house fan and NO AC, zero AC during this horrible summer: July $68, August $56. So this model will pay for itself very fast.
Installation was simple but not easy.And i did make a few changes i felt would be improvements, though not necessary.
I chose to place the fan in a central hallway, center mounted on top of a single ceiling joist. This is a standard/primary way of installation. The hardware supplied is sufficient to get this done. But i added some support/stability with 2 furring strips on the OUTSIDE of the fans wood box/frame PERPENDICULAR to the joists. My joists are 16 on center, so the 24" fan unit, when center mounted, had 12 inches left/right of the joist it rested on above nothing. It STILL rests above nothing on 2 sides, but i spanned 3 joists (the Lt-CTR-Rt) with the added strips of wood. Depending on how you mount the frame you may want to support either Lt/Rt or Top/Bottom sides. But the entire fan unit weighs little, the hardware supplied is probably adequate, i just felt better securing it across 3 boards. IF you use the CTR mount/single joist setup you CANNOT pass the fan upwards into the attic from below. The opening that gets cut for the louvers, and the joist that you will be using for installation will not allow passage. The fan is just a bit too big top to bottom to pass through. If you have a decent attic access you are fine (i don't).
The other installation option is cutting through a joist and securing the fan into a custom made (by you)frame. I did not use the "cut joist" method, but it did cross my mind at one desperate moment.
This fan can be installed vertical or horizontal. It cycles Hi/Low/Off from a pull chain. You can wire it to a wall switch, but i did not get into any of that. If you install vertically you will need to use a switch because the pull chain won't work. DO NOT INSTALL near gas pilot lights. So much air is drawn in it's possible to extinguish the pilot lights, resulting in a gas leak... so they say. The air drawn in part i have no doubt about, this fan moves air.
THIS IS A MUST: You MUST have adequate ventilation OUT OF the attic for the fan to work. It draws in thousands of cubic feet of air every few minutes, and that air has to escape the attic. I installed 7 more roof vents to be certain the air could get out. There is a formula you can look up, but it got too WTF? for me. My ventilation/roof area is about 30 ft 16 or so. I have 8 pan style vents (4 on either side), a turbine type vent and 2 gable end vents. I run the fan on Hi speed and have no problems with noise, ventilation, anything. But you have to allow for the incoming air to leave the attic peacefully. MUST. I guess it will sound like inside a car on the highway with only one window open, the fast air coming in hits the trapped air trying to escape and that horrible headache noise occurs... until you open another window, problem solved. The opposite also applies. When the fan is on you must provide enough air to feed the fan. And it's not like every window has to open or even cracked. Just get enough of a flow through to the fan. If not you burn out the motor.
When i was cutting the openings for new vents, i made a cardboard template of the vent opening. Using some kids "sidewalk chalk" i spaced & marked my 8 positions from inside of attic. Drilled a hole at the top of each template outline and pushed a nail up into/through the hole. The template outlines should be positioned as diamonds, NOT SQUARES. Went out onto the roof, located nails, placed top of template DIAMOND at the nail and sketched/chalked the outline i would need to cut on the roof. Drilled 2 holes with an inch and a quarter bit in each diamond outline, one at the top, one at the bottom. You will destroy about 2-3 bits doing this, and you think you're about to start a fire from the heat/friction/roofing tar/asphalt/drilling going on. Have your gloves on because you will need to wipe off the drill bit and it will be HOT HOT HOT. Be ready to throw away/change the ruined bits. Then through the top/bottom holes use the saws-all to cut along the chalked outlines for the roof vent openings. Nail and putty the vents in place. I puttied all around the openings and the underside of the vents.
Regarding operating noise we are fine with the level(s). I can hear crickets, i can have a phone conversation, hear the toilet flush, the shower running, the dog bark, toast pop up. I/we have no issues. And this is a Direct Drive model, not a belt drive. I CAN hear when it's running, but that's not all i hear. Maybe others are not venting the attic air fast enough.
I would rate 5 star, but i need to know a lifespan/reliability to go there. I wish i had done this years ago. Even if you pay somebody to install it you will probably regain the cost. But be certain the roofing vent issue is covered. Ridge vent and soffit vents count if you have them. But you will never have too much on the exhaust side of the fan.
well i hope this helps somebody get through the installation job and stay cool. Wear eye protection if you're cutting overhead, have a few different lengths of screws on hand, 2-3 inch, in case wood is far off.... that's all i got
48out of52found this review helpful.
Review 14 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
PostedMay 24, 2011
No, I do not recommend this product.
I purchased this unit to replace another fan that quit after 15 years. This fan is smaller than the one I replaced. 24" vs 30". This fan worked OK but it was loud. I could hear it in the basement. I tried a foam gasket between the fan housing and the rafters but it didn't help much. I returned it and got my money back but the manager said that was an exception, They usually don't let installed items be returned. How can you tell how noisy a fan is until it's installed. I wouldn't reccommend this unit. It's loud. sounds like an airplane ready for thke off. Did I mention it's loud?
18out of21found this review helpful.
Review 15 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
Gets the job done but noisy. Belt drive better.
PostedMay 5, 2010
No, I do not recommend this product.
Installed two years ago in 1000 square foot home. Great for making the house more comfortable while saving energy. I recently changed to the 30 inch belt driven model. The difference in noise is incredible, I would say the belt drive is at least half as loud. If you're planning on buying a whole house fan spend the extra 80 dollars for the belt driven model.
11out of11found this review helpful.
Review 16 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
Our drywall finished garage used to be like an oven, with no ventilation at all. The garage is 960 sq ft which was perfect for this product. I hard wired it to the electrical outlet also used for the garage door opener, and use the two speed pull chain included to turn it on and off. Since this was installed for use in the garage (not the house) the noise doesn't bother me. However, there is a bit of noise to consider if you decide to install it in their recommended hallway location.
11out of13found this review helpful.
Review 17 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
I live in the mountains of north Alabama, the nights are cool in the summer so a whole house fan saves me running the A/C 7PM-8AM. Although my home is in excess of 5000 SQ FT, the 4500 CFM fan cools my home in about 30 minutes after the sunsets.
6out of6found this review helpful.
Review 18 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
from Commerce Township, MI, USA
Age Range:65 or over
PostedMarch 25, 2013
No, I do not recommend this product.
Only installed one day...Way too loud for the upstairs hallway where it was placed...Sounds like a jet taking off it is so noisy, even at the lower speed it is un-acceptable to run at night...Probably just run for short time in summers to cool upstairs bedrooms and then shut if off and use air-condtioner as before....Hope I did not waste my money...
Pros: Great Value, Easy to Clean, Economical
Cons: Noisy, Too Big
3out of3found this review helpful.
Review 19 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
First off, the install instructions are completely worthless. Hopefully you will find these tips helpful. The fan comes attached to a frame that rest on top of a truss in the attic. The frame as pre-drilled on all 4 sides giving me the impression I could install it oriented any direction I desire. I oriented it such that the electrical box (and thus pull chain) were in the most convenient location. Upon completing the install, I went to install the cover and noticed the hole for the pull chain pretty much limits the install to 2 directions not 4 since the pull chain has to be close to the truss. Why they have pre-drilled holes on all 4 sides when a specific orientation is required is beyond me.
Then I noticed the thing wouldn't even fit. I installed the fan with the 2 brackets drilled into the truss and then built 2 u-shaped pieces of blocking to block the fan and ensure it was sucking air from the home and not just recirculating attic air (and insulation) per the worthless directions. However, with the 2x4s in place, the cover was too wide to fit. If I were to move the 2x4s further out, they would be blocked by the support brackets and if I moved them beyond the support brackets then they would be so far away from the fan, they wouldn't do the job intended. I am still not 100% sure why but the only thing I can determine is that the brackets are supposed to be on the INSIDE of the box rather than the outside. The directions do not state which side. This would allow me to move the 2x4s out a little to give room for the cover. The problem is that after I finished and tested the fan, I used spray insulation to make sure I had a good airtight box so that air and insulation in the attic wouldn't get sucked in. I now have to scrape all of that off, take everything apart, and basically start from scratch.
Hint 1: Despite holes for the brackets on all 4 sides, make sure you install the fan so that the pull chain is near the truss. I guess if you aren't using the pull chain, you might be able to get away from this but it isn't worth the risk.
Hint 2: Put the brackets on the inside of the fan box. Putting them on the outside seemed more logical to me (wider is better, more stable) but if you do it that way then the blocking you build will either not work or not provide room for the cover.
It does seem to move air ok but I think when I take it all apart I will exchange it for the bigger unit.
17out of19found this review helpful.
Review 20 for 4500 CFM Direct Drive Standard Whole-House Fan with shutter
I put this fan in last weekend and it works great. It is a little load but I was expecting that from a big fan. My house is 2100 square feet. The direction are not even worth opening so you are your own to figure it out. Putting one in my buddy’s house this weekend. I wish I would have done this years ago because my upstairs can get very hot and this fan makes a huge difference in a small amount of time. I also took pink foam board and made a box around it in the attic to keep the blown in insulation away from it.