True that! I lived in attics on the jobs in my earlier trade 40+ years ago.(and visited just last week...) It's a seniority thing. They own the company & you go/do what they say ;`)

It does work. I live on an Island and when elnio hit the Humidity was unbearable. Installed an electric vent and it's definitely cooler.

It depends on your type of roof. How your attic is designed. My house has A Frame. It's Attic height is around 3ft high.

Phoenix energy auditor here. The main issue with the attic fans is that they tend to depressurize the attic with reference to the house interior and thus pull conditioned house air into the attic. I use a smoke pen held up at the can lights to show the homeowners that their attic is getting cooler, in part, by pulling air from the house. (The dirty insulation around the can lights further lends credence to this.) We recommend against attic fans for this reason. Also, a properly ventilated attic, with less high vent square footage relative to the soffit vent square footage, is a more efficient way to go. Stack effect will carry the air from the soffit vents to the ridge/dormer vents. At the same time, we recommend proper air-sealing around the house-to-attic penetrations. That said, the fans *can* work, but the house has got to be sealed tight from the attic. “In order for the fan to work the air needs to come from the outside and not be pulled from the house so this means that the attic ceiling needs to be airtight. If the attic ceiling is airtight you don’t need the fan. Your money is better spent on something else.” -- Joe Lstiburek

You’re probably correct because the attic fan is pulling cold conditioned air from the living space into the attic thanks to the negative pressure effects. This is actually NOT what you want to have happen as now your central A/C is cooling your attic-an unconditioned space.

I agree in some applications they will save energy on existing homes I am a HVAC professional

I partially agree with him. I've looked at the solar-powered vent fans and they contain a computer cooling fan!!! My range fan over my stove is more powerful. I'm looking at the AC powered ones but still evaluating. I'm wondering if just installing a powerful range fan or duct booster fan under my current wind turbines will do any good. I'm researching that too.

I have a 1913 church building with zero attic ventilation. With no ridge vent, and no eave vents, my solution, until the next roofing job is to place to electric roof vents, and bore multiple holes in the 2x6 blocking the path to the eaves. Seal off the attic from the rest of the building. Sure, roof venting is needed at the time of the next roofing job.

I disagree as well. I had a solar attic vent installed years ago (in Texas) summer electric bill dropped 100.00 per month and it allowed me to get the house much cooler. 100% fact

Attic fans are terrible because the manufacturer refused to pay for advertising on this channel.

This dude has 0 scientific evidence, or examples showing it doesn't work just "trust me man it doesn't work"

Attic fans are not a scam and I disagree with the way they were presented in this video. However something I will point out is that most people should not be looking for an easy solution via an attic fan, they should be addressing the actual problems. These include but are not limited to blocked soffets preventing proper airflow to the attic, poor air sealing between the attic and the living space below, lacking insulation, etc. So in that regard I would not suggest an attic fan. I would fix the reason my attic is reaching 150f degrees to begin with.

You should check into what people who actually study building science, and use it to test for and fix problems with homes have to say about powered attic ventilation. None of it is good. In the vast majority of cases, powered attic fans are detrimental to a home to some degree, or at best neutral. When there is an actual perceived benefit, like you claim for your house, it is a band-aid for a home with serious thermal and pressure envelope problems. You would be much better off actually fixing the source of the problems with your home.

@@markbeiser Provide links. I've seen enough people trying to deny basic thermodynamics on this subject to take claims of actual harm to the home based solely on improved ventilation with suspicion. Also, the home is relatively new and completely up to code. Additionally, the entire roof was reinspected for problems when I had it re-shingled. Finally, the anti-fan crowd appears to be an extremely small minority. If attic vent fans were truly harmful to neutral in effect, they wouldn't be so popular and it could be, and would be, easily demonstrated without resorting to moronic claims that moving the hot air out of a mostly enclosed space doesn't cool it off.

@@Doctaphil64 probably the reason it’s 150f is the god damn sun, so fix the sun?

You in all the way south Alabama?

True. Power attic ventilation is great at night. In my house, there is three times faster cooling of attic construction, which gives you great buffor during the day, and much lower temperatures during sunny days. Thermal transfer to level below is reduced or even canceled during some part of the day. It is great solution.

THIS!

Hard to cool down when the sun goes down with a solar powered fan.... lol

@@garbizwal seriously?

This guy is so full of _hit and doesn't know what he's talking about when it comes to using to attic roof fans.. Where is the test in the attic to prove this ? My upstairs air conditioner runs so much less during the hot summer after installing the attic roof fan. my walk out attic is 15 degrees cooler and now I can go out there in the day time. What a moron !!

yeah, you want to be sucking the coolest air however, if your entire house is vented, you are sucking cool air from everywhere. I think the atic fans work best in areas other than texas or places with 100f weather because sucking 100f + air into your atic, isn't gonna make a big difference. I live in southern california where its been 75f for the last 3 months straight and its almost July. This week its pretty much 80f. Sucking 80f air into the attic that would be 120f, without the atic fan works well.

I like the poster, and he's pretty smart but even smart people get it wrong sometimes. Like I said, he's partly right in climates that are above 100f. He should have mentioned that.

I agree with you. Here in the Okanagan valley very hot summers. Installed a few of these and the customers reported back cooler upstairs on hot days.

I agree with you. I installed a gable vent fan on a friend's house. The rafters were so hot that you couldn't keep your hand on them. You also couldn't be in the attic for more than about a minute. After install, it was still somewhat uncomfortable but you could touch the wood and could be up there for hours without dying. Of course, the electric bill dropped too.

@@cyborgdale there is a reason us HVAC people if we run into a house that has no ventilation in the attic and equipment is there, we will pull a salvage furnace blower and put it on a gable vent and turn it on for 5 minutes before staying up there for longer periods.

@@ouimetco Okanagan Valley? Hot summers? ha. Do you understand, this video is from Austin, Texas?

HouseORudd I have been to Phoenix once and ya it was cooking. Hope your staying healthy down there. Lots of horror stories in the media about the pandemic. Cheers man

Facing this issue today. Couldn't get below 77/78 inside the house today in Atlanta to save my life. AC working well and doing all it can do. I have to think that if my attic was a bit cooler I could have gotten my temp down inside the house.

@@tima.478 Do you have an attic HVAC and how are your soffits* doing?

@@Doctaphil64 Unit is in an unfinished basement. soffits vents are about 10 to 15 feet apart, all around the house. The vents themselves are a cluster of about 15 holes, each 3/4" in diameter, covered by a grill. I am actually thinking of removing the grill and making just 1 large cutout under the grill. This might bring in more air than a cluster of holes. I did recently notice that there is a ridge vent that goes across the entire length of the roof. Let me add some backstory: I had the unit turned off on a day that was close to 100 degrees. I was cleaning out the AC coils, fan, compressor area. By the time I got it all cleaned and turned back on it was 78 degrees in the house. The unit simply maintained that temp and was never able to get below that. On a typical day, it has no problem maintaining my usual 72 degrees in the house. My thinking is that a properly functioning unit should be able to achieve whatever temp you set, no matter how hot it is outside. Maybe that's just not always the case, especially in extreme heat. Thoughts???

@@tima.478 I live in Texas and I cannot get my upstairs below 77+ any time it is over 100 outside. Using a temperature gun I have measured the temp in my attic at over 156f! In my case the lack of ventilation was the problem. My soffit vents were too small and too few in number. If you do believe the attic is the problem I highly suggest getting one of these $20-$30 infrared temp guns. Get up in the attic when your home is the hottest and measure the surface temperature of your attic floor's insulation. In my case I had too little insulation AND very little airflow to the attic. Additional insulation provided the base thermal barrier I needed. Cutting six new soffits and an attic fan fixed the attic's lack of air circulation. While all of this has been very helpful, it actually has not fixed the situation entirely. Upstairs still cannot cool below 75f when it is over 100 outside. I have a company coming in soon to install a radiant barrier as the final straw. My only other option after that will be to get a bigger unit, heh. Backstory: Two story house in Texas. First floor stays cool, second floor 77+ on hot days. Attic surface temps were reaching 156f before I intervened.

Did you install the active attic fan IN ADDITION TO a soffit/ridge vent passive system that already existed? I’m getting my roof replaced in a few weeks and they will install passive soffit/ridge vent system and I was wondering if I should have them install an active fan while they’re replacing the roof, or if the passive system should be enough.

I am thinking the same thing. How much does the 36 windows cost?

@@dr_920 Probably a lot more than you will ever save in energy savings

Not of you repaired your old windows and used a storm, they would be much closer to a new window. Plus, those new windows aren't built for a lifetime, like old windows are. They are rebuldable. Plus, you can now add e coatings to old windows if you like. I rebuilt my windows with new glazing, rope, glass where needed, spring bronze to seal out drafts, and it came to about $37 per double hung window, which should last another 150 years. Add a storm and I have insulated glass, same as new windows. I priced Anderson for my old house, and they were about $39,000. I will die long before those break even.

@@miragesmack007 Do you have a link for the things you have done? I am thinking about replacing the glass myself. I got several quote, but cheapest one is about $150 for the glass only. Including the labor, at least $300 each for a 34x28 inch glass. It is will expensive than I expected.

My guess is you replaced old worn out windows. If you restored the old windows, like I always do on old houses, there is little difference. Eventually those replacement windows will live up to their name, they will need replaced. If you had old wood windows, they were rebuildable for the life of the house. But no one maintains windows, they let them go. Single pane is R-1, and double pane is R-2, then other factors increase value somewhat. E coating reflects light, but you can install that on old windows. Then there is gas. My friend who sells windows told me, the only thing he can guarantee, is that the gas is going to leak out eventually. Which gets you back to an R-2 window again.

yep, same here in Florida. This guy misses the entire point of why attic fans keep the house cooler.

He is just thinking of what he can say to argue against attic fans. Otherwise he would have actual data and video

Living up north I had 3 ft icles hanging from the gutters and had the home sided with perforated soffit and the icles disappeared.....

He’s talking about an attic over a conditioned space that uses AC. He is not talking about a non conditioned garage space with an attic over it that’s not in the home envelope. You can do whatever you want there, that isn’t his point.

jim yeats my sister has one and it works. And it’s over the whole home. Without the attic being at 150° there’s less heat getting into the home. Therefore the home is not getting as hot. It doesn’t suck the ac from the home into the attic. It gets the hot ass air out and replaces it with ambient air from outside. There isn’t enough suction to pull ac from inside the home over the wide open vents all around the eve.

In Australia here, have them and 100% agree

I agree with you. I put one on my house in Texas about 2.5 months ago and I also added about 20" of blow in insulation over what I previously had (30"+ now) so I'm fairly certain my cooled vs uncooled envelope are not interacting as much as they once did. I also maintain a temp and humidity sensor in the attic as well as outside so I know what my conditions are. I never see more than a 20* difference in temp between the attic and outside air. It should be noted that I went for the highest CFM and watt solar fan I could get and where I installed the panel gets direct sun about 85% of the day so it runs constantly when the sun is out.

As a person with a pretty good head on my shoulders, I would have to disagree with Matt on this issue. I say that as long as there is enough makeup air to compensate for the exhausted air, then there is no reason why an attic ventilation fan can't be very effective. You must match exhausted air with an equal amount of intake air. This is ventilation 101

100% I like this guys videos, however his info in relation to southern california, (Orange county) is just false on the attic fans. Maybe with the solar fans, but growing up in my house I just remodeled, we installed a powered attic fan and it literally took the temps in the house down by 10 degrees. Maybe his info is specific to 100 plus days which we never see. His microwave analogy is bad. OK, the roof is hot. Theres a space between that roof and the ceiling of the house. He's saying that you can't cool off that space with a fan? A microwave oven does not heat up the outside of the oven. Duh. This logic might work on some dude who works in the walmart accounting office but not where I come from. HE says texas a lot in his video, maybe that's the disconnect.. If I were to believe his analogy, then the water cooling system on a cars engine is useless. OK..... next....

How much was it installed ? I’m in murrieta.

He's a hack.

I live in Illinois, attic fans definitely work. Build has this one wrong.

​@@fastj1962Amen brother. South cal attic fan lover here too. It's really a game changer IMO

He completely misunderstands why moving air through the attic keeps the house from heating up.

He comes off like a dick.

Ok well my attic was 142 degrees and now it’s 90. My electric bill went down almost 100 bucks 🤷‍♂️

Turn mine on in summer off in winter

Thanks! The whole point is to lower the attic temp to 10 degrees above the ambient temperate

The new ones have thermostats so you don’t even have to turn them on and off. They work amazingly this guy is wrong his science doesn’t even make sense Solar Fan is a great idea

​@Ray96744 Such a claim against solar attic fan not working is ridiculous. I am a big fan of solar attic fan, how can air circulation in your attic is bad compare to none at all. Those whirly birds don't do crap.

Seems logical, not sure what setup he is talking about drawing your cold a/c from your house, must be an attic with sealed off gable ends he is using as a comparison, never seen any of those.

I did not know about solar powered vents I live in north eastern Montana winters extremely cold summer extreme hot... well insulated attic no vents during the 16 + hours of sunshine daylight makes it hot it can reach temps over 200°F I cut in two vents (one on each side ). Put a fan in one blowing out. It reduced the temp from +80 to +130 above the outside temp to +20 to +40 above when running regardless if the house AC is running... and when using the AC it runs 2/3rds less. In winter I close up the vents

That’s because cold conditioned air is being pulled from your living space into your attic thanks to the negative pressure from these fans. It’s not solving the underlying problem, but “tricking” you into thinking it is because the attic is cooler. The attic is cooler because your house’s AC is now supplying cold air to your attic as air leaks are pulling that cold air into the attic at a higher rate with that negative vacuum pressure from the attic fan.

@@eggnogaddict6287 I simply don't believe that's true. There's no way those two fans create enough negative pressure to suck air (through 18" of blown insulation) from inside the house. These are not commercial floor drum fans. They move about the same amount of air as a desk fan. If anything, they will pull in air from the perforated soffits around the perimeter of the house. Now if we had a unit pulling 20,000 cfm and huge holes in our ceiling then the situation would be different. Anyways, the benefits of having an attic that is slightly above outside temperatures and not 160 degrees cannot be overstated. You don't have that lingering thermal mass overhead, and you save a lot more energy because the HVAC system doesn't have to cool the ductwork before cooling your house.

@@wabio I mean, you can believe whatever you want, and it seems like you’re defensive because this is your current setup you spent real money on, and the thought of it being incorrect means not only did you waste money to not solve the problem, but if you are wrong then that means you have to eliminate your attic fans and spend thousands more to do it correctly. There are reasons why roofers don’t combine multiple exhaust methods for a roof. For instance-a ridge vent with gables, or a ridge with a passive wind turbine. The effects are detrimental to air flow within your attic resulting in a humid attic risking mold. Likewise, adding a powered exhaust with passive intake is a terrible idea. You want the intake to exceed the exhaust for the very reason of the negative pressurization you create. With undersized intake, your exhaust “sucks” air from wherever it can find it. That means from within your conditioned living space. 18 inches of blown-in insulation is not an air seal. Insulation is a barrier to conductive heat transfer, not air leakage. You stop air leakage by air sealing gaps with foam spray or caulking. A layer of batt insulation or 10 feet of blown insulation is not an air seal. The air loss moves through the insulation fibers. Do yourself a favor and scoop up a handful of insulation and tell yourself that stops air leaks. Then, caulk or spray foam a gap and see if any air flows through it. Done correctly, it won’t. Cover the gap with blown in fiberglass and blow lightly on it. The fiberglass will move and allow air through. You don’t solve air leaks by adding more insulation. You move the insulation out of the way to caulk/foam the gap. So yes, attic fans do create a “suction” effect pulling conditioned air from the living space whether you want to believe it or not. All laboratory research points to this fact. The DOE recommends against attic fans for this very reason. You just seem incredulous that a small fan could do this. Have you ever blower door tested your house? One fan in your doorway finds leaks through the entire house. I just blower door tested mine and found leaks in my basement from a fan on the floor above me on the other side of the house. So yes, fans do more than you think or “believe”

@@eggnogaddict6287 Yes, and I will still continue to argue attic fans do much more good than harm. I've yet to hear anyone say their electric bill has gone up after adding attic fans. Have you? But there are scores of people who have had their energy usage go down....just read the comments. If these fans were pulling mass amounts of cool air into the attic, their e-bill should skyrocket should it not since they are essentially adding a lot of square footage their AC needs to cool. It would be analagous to opening the door between your house and garage and blowing cold air into it. Your electric bill would go way up. BTW the primary function of attic insulation is not to stop conductive heat transfer. It is to stop convective heat transfer by retarding the movement of air. The batts or blown insulation have millions of tiny air pockets that essentially stop air movement. So the hot air stays on one side and the cool air stays on the other. So to say that mass amounts of air is leaking from inside the house, through R60 insulation, and out the attic fan is a stretch IMO. As many others have already stated, the air movement in the attic will follow the path of least resistance (just like your blower test). When the attic fans pull air out, the majority of the air replacing it isn't coming from the house. In our home, it's coming in from the 75+ feet of perforated soffit vents around the house. Anyways, I have absolutely no regrets or remorse buying those attic fans. If I did not currently have them installed on my house. I would gladly spend the money and have them installed today even after reading all the pros and cons. Our attic temperature is just above outside temperatures during the summer and gets pretty hot here in Texas. 2 story house is 4100 sq. ft with 25 ft cathedral ceiling and a total of 52 windows throughout so it's no cakewalk in term of energy conservation . Our e-bill is under $200 per month in the summer with thermostats set at 76 @ $0.13 per KWh.

@@wabio absolutely ridiculous. You air seal the attic floor and then add insulation. The insulation is not an air sealer and conditioned air moves through attic insulation when the attic floor is not properly air sealed. Adding more insulation does not change nor solve this. From the sounds of it, you must stuff batts into the rim joists, too, huh? Do yourself a favor and read up on batt insulation in the rim joist and how that design actually results in a rotted rim joist. How, do you ask?! Because the insulation with “millions of air pockets” allows humid air THROUGH the insulation, touching a cold wooden rim joist in the wintertime. The result is condensation as humid warm indoor air moves THROUGH the insulation and condenses. The solution is to air seal the rim joist and add rigid foam board. Batt insulation is an absolute worst practice precisely because air passes through it, trapping moist air that condenses and rots the wood. Same principle applies. Air isn’t “trapped” by loose blown in insulation. As I said, pick up a handful of insulation sometime and blow on it. Let me know if it traps air, would yah?

I replaced all the windows in my 1200sqft house. They were all single pane aluminum frame. The windows were VERY loose in the frame. They were USELESS.. They were all replaced with dual pane with that silver stuff and argon inside.. I went from running the AC all day. to running the fans at night. The cold air would stay in my house all day long. Saved me OODLES! And yes. Attic fans work.. I run mine for about 3 hours before I have to get into my attic now.. Takes the attic from about 140+ to 80. Helps so much!

@@austech360 well now that's a great point. Whether the fan is pulling AC from the house or simply helping push out hot air and replacing it with ambient air, it's a great discussion, but who gives a rip if you have to go into the attic to do things? Attic fan is easier and cheaper than hauling a portable AC up there.

I don't understand double glazing is pretty standard in the UK and most northern European countries. Triple glazing is common in Scandinavian countries.

The roof deck will still also radiate heat into the attic. Stand in an unfinished garage on a hot day and then hold an umbrella over your head, you can feel it

Radiant energy can penetrate surfaces that appear opaque to our limited range of visual sensing. So, yes, some radiant heat blithely passes through the shingles and is not IMMEDIATELY converted to conductive at the roof surface level (not everyone has shingles) thence convective thermal energy. kzfaq.info/get/bejne/gspoo9162pqZdmw.html

@@vennic Thank you. Much radiant energy is converted into conductive thermal energy thence convective energy, but not all. Just because a surface appears opaque from the standpoint of our limited rage of radiation perception (aka vision) doesn't mean that some radiation blithely passes through it.

If the eave vents are not plugged air will freely move back to the attic and the "negative pressure" is inconsequential.

If your ceiling isn't air tight you can potentially pull conditioned air from below into the attic. I totally agree on airwave and fan scheduling. My upper floor is 3-4 degrees warmer without it.

I agree 100%.

3 differences: 1) Static attic vents (industry standard) will let hot air out and pull cool air in just by the natural pressure differential between the free, cooler outside air and the hot attic air. This cooler air comes in through the soffits underneath your roof and the hottest air will flow out the rooftop vent especially with most roofs having ridge vents now which is perfectly at the hottest part of the roof and so that air escapes the easiest. 2) You're cooling your house as well and the pressure differential could pull air from your house into your attic if the pressure is different like what he said in the video. 3) Your house doesn't move. Basically, a house is more akin to a parked car and a static roof vent is like cracking your windows, however, it would also need an air vent at the base of the car door to let cooler air into the car and the hottest air out through the cracked window.

No that thats like opening your windows and then putting a tiny computer fan in the window to pull more warm air out and saying you notice a difference. That fan is not capable of generating the air flow required to cool you or the car.

Or it's like saying cooking with the oven door open is just as efficient as with it closed.

Well, houses don't move, so you can only compare them to a parked car. So what you just described is passive ventilation, which is what he promotes. It's actually like saying installing a roof fan in your car will cool it down if you insulate and air condition under the car. Then the fan can pull the air conditioned air air up into the car like it does with houses. If all you care about is the attic being cool, just skip a step and run ducting up to the attic from your AC, the efficiency will be similar.

@@ryckXattack Also - you're not pulling very much conditioned air from the house - that's what soffit vents are for. Putting an attic fan is the equivalent of instead of sitting in a hot car with windows down - driving it, AKA forced air. And another point - you talk about air conditioning the attic? Insulating the rafters makes the attic conditioned space, so that's EXACTLY what you're doing when you spray foam rafters - you're air conditioning the attic.

That's the main reason why I put in an attic fan. Reducing the humidity in the attic has helped a ton.

You guy are a riot. THINK: How does taking in humid air from outside reduce humidity in your attic? It doesn't! This is a classic blunder and misunderstanding of what "relative" humidity is.

@@sprockkets Go study the relationship of grains of moisture in air to the air temperature and you may understand how moving 95* air in Georgia through a hip roof attic will reduce the relative humidity of the attic air and reduce the temperature of the sheetrock ceiling in the afternoon and evening making the energy costs of a properly maintained A/C system less than it would be otherwise.

Don’t forget power venting your attic pulls cold conditioned air from your living spaces, so now you have more load on your HVAC systems to cool an area of the house you shouldn’t be cooling. Far better solution is for soffit/edge vents with adequate exhaust in the form of a ridge vent or turbine.

Bingo.

Not true. If the pressure in the attic remained atmospheric, then there would be no air entering through the soffit vents. To create airflow, you need to create a pressure differential. As he said, the same pressure differential that draws air in through the soffit vents can also draw conditioned air out of the house through holes in the wall top plates, holes around light fixtures, etc. Also, one of the main rules for attic ventilation is that you NEVER want more than one type of vent on the roof. Most houses already have ridge vents, turbines, etc, which don't play nicely with power vents.

@@averyalexander2303 The pressure differential is what drives this air movement as you say, but big 2 foot by 2 foot vent holes on either side of your attic is gonna let a lot more air into the attic from outside than all of the combined nail size and smaller holes in the ceiling. Air is gonna take the easiest path with the least resistance. That's fluid dynamics 101. Sure, some will come from the house, but 95% of it at least is coming in through those vents.

@@lukew1383zero should come from the house. Anything more than zero coming from the house is too much

@@HomePerformanceGeeks I agree, but I also understand that people building houses are not perfect. The barrier between the attic and the house interior is going to have some holes in it. I never say anything is 0% or 100% because in the field, that is an impossible standard to reach.

Before I replaced my double pain aluminum windows there would be days in the winter where ice would build up on the inside of the window frame.

I would have to agree with you! He is pointing out worst case scenarios, oversized air conditioners oversize ventilation fans or lack of soffit vents! My parents live in New Jersey and last year their attic fan stopped working! So I replaced the fan and also replaced theThermostat due to its age! A few years ago I installed a four channel weather station that measures indoor temperature, outdoor temperature, garage temperature and Attic temperature! I just got off the phone with my dad to ask him how hot the attic was when the fan broke, because he watches those temperatures all day long! (Being retired he’s kind of bored) He said on a 95°F day the attic was about 135 to 140°F and with the fan it is about 110 to 115°F! As long as you have enough soffit ventilation or you do not install a fan that is way too big for your attic you will have no issues and it will cool the attic significantly! As for windows I purchased a home five years ago in South Carolina that had single pane windows! So I replaced all the windows and insulated properly around them! I can Positively say when the old windows were in my air conditioner used to run much longer and come on twice as much! The air conditioner stays on about half as long and remains off twice as long! Now my electric bill is a lot lower all year long! The money I spent replacing my windows I got back on what I am now saving on my electric! Anybody can sound convincing in a video by themselves without anybody to argue the other side! Oh and by the way that attic fan I just installed is only the third fan since 1984! There are a lot of nice homes and cool ideas in his videos but sometimes he can really talk out of his ass!

I have seen 30-40 degrees difference in Spotsylvania/King George VA with a wireless thermometer in the attic and powered fan. Much hotter now that the motors burnt out and got disconnected (and the landlord won't replace them)

Matt how much did it cost and how did you manage your comprehensive energy analysis? Did Dominion help in the cost at all?

I live in Virginia also (Hampton Roads area). This is our second summer in this house, and the first summer with a powered attic fan. Our electric bills this summer have been $60-$80/month lower than the same time last year.

@@ronirby4496 what fan did you get? Im considering putting one myself.

I stayed in a Manhattan hotel once with single pane windows. Good lord was it loud. Might as well have left them open!

Heh, double glazed windows, how quaint. In the parries in Canada, the better homes have triple pane windows! Need it to keep the cold out in the winter, and the heat in the summer! My parents replaced the double pane windows with triple pane shortly after they bought the house. I always wondered why being in almost any other house always felt colder and draftier.

@@jblyon2 Same thing for me in a San Francisco hotel.

You should try some triple Glazed windows 🤷‍♂️

I got my Nest E on sale and it cost me less than $10 after rebates. Definitely worth it. Plus, the airwave function of the Nest only comes on if the humidity is low! So if you're in the west or somewhere else with lower humidity, you can take advantage of the cold left in the coils to do more cooling instead of just wasting it! I also use the fan setting because I have a basement with cool air that I can pull from and circulate around my house, providing cooling without having to run the AC compressor.

You have to remember the duct insulation isnt super thick so with arid stagnant temps in the attic that heat is going to heat the air in the ducting too so with a positive discharging system for that heat you should see lower bills as the cooling system doesnt have to work as hard to cool the air going into the conditioned space. In theory I can agree with Matt that a single deck vent by itself (during the day) isnt going to be able to make a dent in the attic temps. Add an intake fan thou which creates circulation and I disagree in them being a waste.

Same here 👏🏽👏🏽👏🏽

Yea I am going to have to agree on the thermostat points. There's also the convenience factor. Wake up in the morning, walk into the hallway, thermostat greets me with the outdoor temp, weather, and temps for the day. I deploy a lot, it's nice to check on that whenever. Back when I was troubleshooting a bad condenser fan, it was really nice to not have to go in and out of the house 37 times, because I can just run it from my phone. Plus it just looks great. Say you are selling your house, what do you think is going to impress a potential buyer more, a faded beige box on the wall or a stainless steel ring with an LCD screen?

NYG&E had the Sensi for free (pay shipping and tax) so I got one. Liked it and next year they had another rebate where it was $25 so I got a second one for upstairs.

I've considered going to a big box stores and getting one for my bedroom. It can be SO uncomfortable during the summer nights and mornings.

I'm pretty sure what Matt had in mind is a central dehumidifier (based on his previous videos) which will run you a lot more than $150 and not worth it in my opinion. Your A/C should dehumidify just fine. But your suggestion is much more viable.

150% agree! I just got a little freestanding dehumidifier - nothing fancy like what Matt has shown in previous vids - and that thing has made a WORLD of difference! In my next build, I will definitely install a full-blown dehumidifier system - non-negotiable. I will never be without one again.

And then the seal breaks and the windows fog up and water etched the glass. New window time. I am keeping single pane and getting storm windows.

He's talking about remodel rip offs though

pretty sure you can't buy new single pane anymore.

@@lynxdiamond4888 how is upgrading your windows from single pane to double pane insulate a ripoff? this guy is absolutely wrong about every "scam" he made his video on.

@@ericgustin3386 You obviously didn't watch. He said on a remodel, the payoff is a lifetime if your goal is energy savings.

@@ericgustin3386 have you ever priced out new windows for a whole house? You'd have to be in your house minimum 20-30 years to justify the expense. They also at best improve the value of your house to the tune of maybe 70% of the cost. So if you are putting in new windows to sell in a couple years, you are again losing money. Your money would be much better spent adding insulation to an attic, upgrading an old hvac system, new water heater...

What’s cfd

@@captainmigs1655 Possibly "Computational Fluid Dynamics."

He's got nothing.

I've been thinking of installing one too. Dumb question do you have to leave the garage door open slightly or install vents anywhere to bring in air from the outside?

If your conditioned space is sealed from your attic (and the only place it can pull fresh air is from the soffits) it'll work as intended. If the whole area is unconditioned then it'll work as well. The only time you'll run into a problem is if you don't have soffit vents or if you don't have any sealing between your conditioned space and your attic. It's just a more aggressive version of the ridge ventilation most roofs already have.

Yeah, I did the same in my attic (insulation on bottom, nothing on roof) and it improved the air quality and temperature substantially.

You are right. powered ventilation systems are helpful to speed up the time of cooling in the night. Think of fans to control heat in desktop computer cases.

We have one too and it made a difference in our cooling bill. It makes the biggest difference at night. Gets rid of the hot air and plus in the cooler air. Our house has vents in the attic so it does not pull any air from the house.

No

#Yuhhp

I know of Whole House fans for your attic to be good. Is there a scenario where an attic fan will work good?

Attic fans also increase pollution in the house.

Coolsdown my attic by 8 to 10 °F and fresh air blows continuously throughout my house👍

Incorrect. It's bad in any climate.

His point is powered attic fans are a rip off. Didn't talk about regular attic vents which obviously are important.

@@shootthechit I'm sorry, did the algorithm wade you and other losers to a video from over a year ago? Tough sht.

@@shootthechit see if IGAF

Karl Lundin you are correct. In a hot and dry climate the more attic venting the better. Otherwise your attic will be 160F in the summer and your 40 year comp roof will only last 20 years.

Agreed. I did my own installation of a wired attic fan a few years ago, and measured a before and after attic temp drop from 160 to around 120 during the heat of southern summer. The attic was designed with ridge vents and soffit vents, and the fan addition dramatically helped the HVAC system keep the house cooler. Was one of the best $120 I ever spent.

Karl you are incorrect, no presumption is being made. All fans have a negative pressure and positive pressure fronts, doesn’t matter if the fan is installed on a sealed container with only opening is at the fan; it will depressurize the container.

Jason Villamil well thats weird, my house came with one and doesnt help the house or even just the attic cool off.

Added a Solar attic fan...20 year old house...ran air during the day, not at night. But upstairs still warmer and uncomfortable. With the solar fan, it kept the upstairs cooler. Instead of 2 floor fans and 1 ceiling fan at night in the bedroom, now we just need the ceiling fan. Best $300 investment I ever made.

Same. Huge difference in my house that was built in 1900.

Yeah, he's wrong on this one. An attic fan alone won't usually solve the problem, but it is part of a multi-step solution. I've had them make a big difference in numerous houses, including my own.

Can also be very useful at venting humid air that has leaked into the attic from the living space.

They're good if you seal off the rest of your house

Well, in his defense, he only does jobs that are new construction or complete renovations, and he insulates the roof, the rafters, and would probably build a giant umbrella that would block the sun from reaching his customer's property entirely if he finds a rich enough client. "Why spend $500 installing a fan when you can spend $15,000 installing a new roof with 6 inches of foam insulation?" ... A true salesman.

You know you can get a cheap wifi or Bluetooth thermometer so that you can do this without a camera. Keeps detailed historical readings for you as well.

@@owenf4535 I was sure that I had checked this out and that I was disappointed. Your reply made me look again and you are right, there are some inexpensive Wi-Fi items out there. Thanks!

Wow a lot of disagreeing

@@davidweggel9573 And rightly so.

@@PianoUniverse Exactly 💯

agree 100%. I am in Az and its 110 outside, attics are 140 if properly ventilated. If not- they are pushing 200. He needs to stay in his lane---and stick with building and not try to be an expert in everything.

I am also skeptical of his theoretical pontifications. If you have 300-400 s.i. net-free area in the eave vents, how could that little fan possibly create enough negative pressure to suck gobs of air out of light boxes and walls? Matt is not the only one who pooh-poohs the attic fan-Joseph Lstiburek trashes them also. I think they are harmless at worst and mildly helpful at best. I have never seen a controlled test, yet these fans have some very dogmatic adversaries.

Tests to prove otherwise would be nice. Best I can tell, his argument comes from math, which no one seems to want to disprove.

I have a radiant barrier and an solar attic fan and when my attic fan died, i definitely could feel the difference in the house, until we replaced it.

I happen to have a tester in the form of a 12x20 short gambrel shed (see big comment above) with an off grid powered (fabbed) 900cfm 12 volt fan in a mushroom style passive roof vent. On a 95 degree day the back of the plywood right under the shingles is 125 degrees (no insulation yet), and that fan running at full speed does not change that one whit. And that's with 3 windows open.

I have a thermostat in my attic. It makes a 10-15 degree difference in the summer with 1 powered attic fan running

Has to be one of the worst videos iv seen in awhile.

1) the “giant powered fan” isn’t “giant” 2) the “tiny holes” in top plates, wall and ceiling penetrations, combine to make sizeable leaks when aggregated across the entire house. Always amusing reading arrogant KZfaq commenters who think they’re more intelligent than they actually are.

@@eggnogaddict6287 Lol 😂 okay kid.

@@mastrcraft4067 Nothing better to do, huh?

@@eggnogaddict6287 eh, just depends. Always can find time for KZfaq. Like you, right?

It really is though it releases ionizing radiation

Metaphor. Do you recall that word in middle school I think it was? Some words are literal, others are metaphorical. Calling the sun a giant microwave is what is called a METAPHOR, a way of illustrating a concept.

@@STV-H4H oof you must be fun at parties

Guillaume Duteaud LOL You have no idea.

I laughed pretty good at that one to, The sun doesn’t agitate water molecules in my house to generate heat 😄

Couldn't agree more .

we have one that is thermostatically controlled, the fact that it cycles on and off throughout the day disproves his theory

if an attic fan is lowering your power costs then you aren't insulated properly and are getting massive amounts of heat transfer in the summer and cold transfer in the winter.

In SW Florida we had 140° - 150° F attic and the 5 ton AC could barely cool the house, and now after a 4,600 CFM thermostat fan 100° F and we can freeze ourselves with the AC. The roof is just as hot, but the temperature between the scalding roof and insulated ceiling is 50° F cooler. I'm NOT trying to cool the roof .. I'm cooling the space to the ceiling.

@@DanielRichards644 There is a balance between how much money you want to spend on extra insulation and what will be your electric bill every month. After so many inches of insulation your money back start to diminish rapidly, plenty of charts around to explain and confirm this, so now attic fan becomes so much more attractive - cheap, easy to install, instant payback. I bought two 60 buck attic fans, one blows in from the Northern side one sucks hot air out from the South side and the very first month my electric bill dropped 30 percent.

Also, if you have vacation homes you can save a ton of money in avoiding frozen pipes in the winter and cooling in the summer when you’re not there. I let my house sit pretty close to 80 unless I’m going to be there. Then I can cool it down starting in the morning before I get home. Also, I have a dual zone AC that was never balanced. Now I have assignable temperature sensors in every room and the thermostat does a good job at consolidating them into a comfortable average

They are also great for turning down/up the temperature when you haven't moved for hours while you binge watch TV and schedule thinks you are asleep.

Show it in math and that will validate your claim. Otherwise such comments are pointless.

sorry, but almost certainly you just think it makes a huge difference and in actuality it does very little or even hurts you home's performance.

@@alanr745 Maybe his home is not air conditioned. In that case it would make a big difference.

Alan R Heh- 220+ year old house here- I think you are missing the lil joke. When you have 0 AC and are using open window technology, the power vent is a big deal- it does exactly what he describes but intentional in its function: create a negative pressure to pull in outside cooler air and gets rid of the warm air blanket. He is completely correct when you are conditioning the air artificially with modern tight house philosophy.

romwil how so???

You should try a Z-Wave thermostat along with a hub and a temperature sensor for each room. You can program the hub to calculate the average temperature throughout the house from the temperature sensors and control the thermostat accordingly. Because it's on the Z-Wave wireless communication protocol, it will continue to work if you lose internet connectivity.

Yea man, he never even got into the pure convenience factor of a smart thermostat, which was enough for me to buy one.

@@MAGAMAN I totally agree. There is a small argument to be had if you have A/C. If you don't have A/C, you NEED an attic fan!

I think there's a difference between a "powered vent fan" and a gable vent fan. The powered vent that Matt showed replaces a typical roof vent, which is near the top of the roof. What happens is that as it pulls air out, the replacement air is coming in through the closest roof vents. So you end up with a circulation near the peak that just goes from one vent to the other, and really doesn't cool the attic space. A gable vent fan, on the other hand, pulls air across the attic. It may still pull in through the roof vents, but it's still evacuating more of the space, not just the small area near the peak. I have a gable vent fan in my 40's house,) which could definitely use more insulation...), and I can tell the difference in the living space.

@@JohnMeissen Many houses don't have roof vents and he didn't say powered vent fans were rip off "if x" only rip off If you have plenty of roof and sofit vents then you don't need any additional venting.

@@davidmorrow4195 The only houses that don't have roof vents were either built improperly, or it is a sealed conditioned space. To say "many houses don't have roof vents" is absurdly stupid.

@@ryanroberts1104 I lived in a house that had only had gable vents. When house was built in the 1920's this is what they did. My current house and all of the houses in my neighborhood (1910's) were built without roof vents, also what they did then. Many of them were retrofitted later but the 3rd floor is a living space with a small/medium sized area in the peak that isn't vented. You're ignorance of how houses were built in the past is absurdly stupid.

The thing people don't realize is that the old windows could have been refurbished for less than the cost of new windows. Do you think that in 1930 there was air blowing through a closed window? No...They need to be maintained.

@@bearded4glory809 Crappy old aluminum windows aren't worth it to refurbish, if it's even possible.

@@genli5603 1930's farm house with (original) aluminium windows... I think you will find they will be timber windows.

you might see that the savings came from the cavity around the window behind the trim. most old windows even from 80's are not well insulated when they were originally installed. Pull trim board and you will see air gap. That mostly where air leak and heat/cooling losses happen.

Fine, but Matt is specifically talking about the thermal difference and energy difference between one pane of glass and a multipane glass window, assuming all else equal. The issue with your dad's windows were they were fitted poorly, were uninsulated, etc.

Air is kinda dumb, it doesn't know it is only supposed to enter the attic through the soffit vents. When you depressurize an attic, air will leak into it through every path it can find, regardless if it is from the conditioned space or outdoors, in proportion to the size of each opening. Even with newer homes, where they actually made an effort to seal the conditioned space off from the attic, at least a little air will be pulled from it. You also have to regularly clean the screens behind the soffit vents, or they will become clogged and cause even more air to be pulled from the conditioned space. On an older home where none of the wall top plate and ceiling penetrations were sealed, and/or where building cavities and floor trusses are open to the attic, powered attic ventilation can be catastrophic to the temperature and humidity control.

Noise transmission is reduced also

Surprised he didn't bring up double to triple pane.

@@jaspersonnyoner yeah i used to live right next to the train tracks and you can barely hear the trains at full speed, I live in the UK where new windows tend to be double pane.

@@olympicfireball sadly North America is way behind on moving to triple pane. hopefully we see many people switching over soon, but with big houses with many windows it isn't a cheap operation

@@raysonviswas In urban environments I would opt for triple glazed for noise benefits alone, closing a window can be like closing a bank vault door

Did you hear Matt mention it pulling cool air from your openings in the sheetrock? He didn’t say it wouldn’t work, he explained why it’s a bad idea. If you don’t believe him, go in an old house with a whole house attic fan. (The ones for cooling living space). Slightly crack open a window and turn on the attic fan. It’s shocking at the large amount of draft it will pull.

@@jaye9300 But Matt's talking about those roof fans, not attic fans.

@@jaye9300 I think you are confusing the whole house attic fan mounted in the ceiling below the attic with what Matt is opining on the powered roof ventilator fan which is very beneficial in some roof attics with poor conventional soffit or eave ventilation.

Cooling your attic isn't for the benefit of a cooler living space. Attic insulation satisfies that important job. Cooling your attic protects your roof sheathing and shingles from burning up all summer long. The cooler they are the longer they last. So while I agree the attic ventilation is important for the sake of your roof I'm not sure that the cost and electricity of a fan is money well spent in most residential construction.

@@phillijp Think here bro: Do you really think your attic temps actually influence the temps of your roof tiles when they are in the sun? They don't. That's the whole point of the analogy of you being in the sun on the beach with a fan on you - it doesn't do anything at all.

It isn't any different. Matt needs to actually test this stuff himself before spouting off about it. The utility companies wouldn't be providing energy rebates for window replacements, smart thermostats and attic fans if there wasn't science that showed it reduced their energy load.

i'm willing to bet the box fan pushes a lot more cfm than these solar fans. A quick search on Menards website shows 800 to 1100 cfm. A box fan i saw on Amazon was 2400 CFM. I've used box fans to cool my house and it seems to help. I'm too lazy to read the article Matt mentions but I'm finding it hard to believe its really that big of a problem with negative air if there is adequate soffit or gable vents. Where I live in the north its not really common to have ducts in the attics.

Because now it’s no longer an attic fan. You just said you put a box fan AT THE OPENING blowing cooler air in. That’s not an attic fan- that’s a box fan, at the attic opening, pulling in air. Attic fans are at the roof deck. Attic fans can’t outpace the amount of heat being constantly produced by the sun.

I am pretty sure he said powered attic fans not attic fans in general, but I could be mistaken.

I'll chime in on this as well. I have to disagree about the attic fans as I actually had 5 or 6 of them installed several years back (we have one of those large 2 story roofs that a portion of it actually covers the entire rear of the downstairs level as well, so we 2 placed in the areas above those lower level rooms and the rest in the upper sections of the attic... It's a big attic, trust me) . We built our house in 2010 and in the summer time, our AC just couldn't keep up with the heat in the Austin, TX area and I realized that the if I ever opened the attic access, it was like opening the hatch to a literal blast furnace and the sweat would start running before I could make it up the ladder. After getting the aforementioned solar attic fans installed, this made a HUGE difference and the same ac system no longer had difficulty keeping the house comfortable. Also, on another of his points that I'll disagree with, I switched to the exact Google Nest Thermostats with the Airwave feature that he mentioned, but I don't think he understands how they actually work bc they do have humidity sensors and that helps determine when the Airwave will run. That being said, I firmly believe a lot of these thermostats are not made equally as I switched from Vivint Smart home thermostats (one upstairs and one downstairs) and ever since going to the Nest thermostats, we don't have to set the temperature nearly as low as we did before (my wife is the meat locker temperature type and would set that Vivint one at 66 or 67 at night and with the Nest during the same 90-100 degree temp days, she only needs to set it at 69 or 70). Usually just setting the upstairs one to 70 or 71 will keep the up and downstairs extremely cool and comfortable. This is all running from a single large ac system for a ~2900sq ft home.

Yeah. If you're getting detrimental negative pressure from merely running an attic fan, where's your venting? I don't understand how someone's attic could be so lacking in ventilation that running an attic fan would result in so much negative pressure that air from inside the house gets sucked into the attic.

@@MAGAMAN I do not have zones. It is a propane only furnace. And my smart thermostat gives me poor man's zones.

@@MAGAMAN it's not exactly the same. My bedroom temp changes a lot faster than the thermostat room so it runs a lot more frequently when I have it set to the bedroom. Way comfier

@bobwatters I actually don't enjoy living in a cave, e.g. what it would take to make the curtains useful. I like to enjoy the fruits of my outdoor labor from the comfort of my home. Replacing the windows cost me about $5K. I'll see a good portion of that back once I sell my home due to the update in appearance to the home. And at $40 a month, I see almost $500 a year in lower electric bills, I am not having to have my HVAC worked on almost monthly and I was able to extend the life of my HVAC system. So, I am damned sure that I will come out just fine on this purchase.

@bobwatters how bout stopping the cold in the winter? they make curtains for that? lol. northern climates and resale value. those are the 2 reasons to upgrade your windows from single to double pane insulated. Good luck selling a home with single pane windows. and in a northern climete like maine or mass? forget it. single pane is a joke. you get a MONSTER high heating bill in the winter, and to top it off , your house is never really warm. where do you spend most of your time? in the living room usually on the couch. whats behind the couch? two big fucking windows, thats what. and single pane in the winter up here will literally be blowing ice cold air on you.

We put in new windows and it also made a big difference. Our old windows would almost burn you. The new windows are cool to the touch and our kitchen that’s gets the morning and afternoon sun is now nice and cool. Before the new windows it was always hot.

@bobwatters, not curtains... removable solar screens on the exterior of the windows would've solved this guy's problem for a fraction of the cost of new windows. The solution is to stop the sunlight from ever hitting the window in the first place. A curtain will do little good. At the point which the radiant heat from the sun hits a curtain, it's too late...the heat has already entered the home. It heats the curtain which radiates the heat into the room.

@@eodhowland, I don't know, so I'm only asking..is your hometown hot enough every month of the year for you to see that $40/mo savings?