Air flow: It's all about fan thrust

Testing how much air the fans can move through a window. This turns out to be considerably more than the air that goes through the fan itself, even if the flow is impeded by a bug screen.
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[@AdamEarl2]

I’m a big fan of your experiments, the results blew me away.

[@HeroOfTime303]

Yeah, these videos really catch the wind in my sail.

[@mz00956]

They have a cool(ing) effect

[@ShowLocalTV]

I see what you did there being a "big fan" 😅

[@trezspre]

@@ShowLocalTV”blew me away”

[@jameschristiansson3137]

Go to your room Adam Earl.

[@Karza_357]

It would be interesting to plot the air moved and noise generated to get a "noise efficiency" rating for the fans.

[@matroosoft4589]

This. We have a very powerful fan at home, I think it's 3000W. But we almost never use it, both because it's very heavy and very loud. My in-laws happen to have a very very silent fan and I'm very envious!

[@CRANEREVIEWS]

The sound signature can be more important than just pure noise levels

[@questioner1596]

It would be interesting to see if the noise efficiency remains consistent across all fan speeds. Also, without a testing body, any of these ratings can't be compared across brands.

[@fantabuloussnuffaluffagus]

I'm curious what that 3,000W fan gets plugged in to.

[@matroosoft4589]

@@fantabuloussnuffaluffagus just a wall plug. European outlets can deliver 16A @ 230V. So approximately 3600W. In reality most appliances are limited to 3000W because there's multiple outlets on one breaker

[@ArtHeld]

This channel is the closest I've found to high school physics class - which I still remember loving 55 years ago... Thank you Matthias for making an old fart's morning better.

[@k.hendrickson8735]

Ditto, from this old fartess. I didn’t even know Physics also could be interpreted as “Getting more bang for the Buck”!

[@Castlependragon]

My husband told me about your video and we did a minor test on our box fan that we kept right against the screen door. When we moved it away(about 4 feet), it produced significantly more breeze. Thank you so much for this!!!

[@ShowLocalTV]

It's due to air entrainment... Dyson bladeless fan works on that principle...

[@mr.headcrab31]

Excellent video as per usual, but I'm somewhat surprised you didn't test one of your home made blowers in the test rig as well. Would be rather interesting to see where your trash picked plywood and yard-sale motor creations compare to one another, let alone the store bought competition. Thanks again for sharing.

[@user2C47]

Those blowers were mostly meant for dust collectors, rather than air movers.

[@MrDoroh]

His box fan might as well be trash picked :D

[@mr.headcrab31]

​@@user2C47 True, originally i had thought to ask for a performance test vs one of those stationary squirrel cage fans, or for a comparison of velocity optimized vs static pressure optimized fans. But then i remembered that our gracious host both has kids, a million other things to do, and isn't like Project Farm and willing to buy fans just to test for us. I blame lack of sleep on my part.

[@fumthings]

disappointed not to see the garden blower...

[@davidelang]

I picked up a dreo based on your last video and over the 4th I run a fireworks show and used it to push air into the back of a big box truck to cool it down while we were unloading it. I also had an old school circular fan (slightly larger than the dreo) I asked how well they worked, and the report I got was that the old fan moved a lot of air a short distance, the dreo moved a little air a long distance, but when run together they resulted in a lot of air moving a long distance, so you may want to try combining the box fan and the dreo (next to each other, on top of each other) and see if you see a similar multiplication effect.

[@brainndamage]

It would be interesting to see thrust efficiency (thrust vs power consumption)

[@kk10494]

I picked up one of those Dreo fans, they are very impressive. One of my favorite (albeit mundane) features is that the LED display will automatically turn off depending on ambient lighting conditions, i.e. when sleeping

[@pengting87]

The pedestal one?

[@kk10494]

@@pengting87 Nah the small desktop silver one - though I imagine the pedestal one does the same thing

[@Dukey8668]

The videos on this channel over the past several months are my favourite content on youtube right now. Thanks Matthias.

[@litnoregrets7551]

Love this video. You are a man after my own heart but with far more ambition and know-how. Please keep these great videos coming.

[@LarryKapp1]

I would have liked to see the watts power input to each fan on your graphs. Also as you move the fan backwards in the room you are creating all kinds of air patterns that can effect your sensor . For example if air is going out the back door it will make different readings on that . A smoke test would be interesting see what the air is really doing. Also a blower door test where the entire door is blocked so you see how much positive or negative pressure is created.

[@ronski50]

Agreed, cfm per watt would show the efficiency of each fan.

[@brjan.]

Yep, seems like a miss. Based on listed specs only, Vornado is 44W and Dreo is 48W, which seems to account for the difference between the two outputs.

[@shakeit995]

@@brjan. if you watch Matthias' video comparing the two from 3 weeks ago, it seems the dreo is actually more efficient than the vornado. idk about the rated power but his measurements show 53 and 38W at full power for the vornado and dreo, respectively.

[@ShowLocalTV]

Agree with the power input graph... but the negative pressure measurement would not yield any result... Assuming the house as a closed system... the volume is just too big...

[@k.hendrickson8735]

He doesn’t have an actual LAB… although pretty darn close!

[@briannewhouser154]

Love these type of videos. Very informative. Thank you and keep up the good work.

[@chet3larson]

Can’t thank you enough for the original video. Bought one and have never been so happy with a fan

[@manuelkohpei3719]

KZbin has shown me a nice channel today! Keep up the good stuff! This knowledge is gonna save people!

[@davidoutside]

matthias you're a genius and an angel for doing all this research for us. i will no longer be putting my box fan RIGHT on the bugscreen to exhaust the hot air out of the house. 5 feet is the magic number! thank you my dude

[@TrainFlood]

Just bought my second Dreo DC Desk fan. It's a terrific little machine.

[@johnnyllooddte3415]

great video... love how you answer all our questions on air flow

[@DjangoBit]

Thank you, I really appreciate this analysis. Fantastic job as always!

[@matthiaslange392]

About 2 weeks ago I bought a 106cm Dreo tower-fan, because of your videos, and I'm very pleased with it. Quiet and blows more air on lowest setting than my 46cm honeywell classic ventilator on medium setting. And on highest setting, it's like putting your head out of the window while driving your car. Greetings from Germany, the country with this awesome window-mechanics 😉

[@flyingvish]

Where did you get it? I can't seem to find european distributors

[@matthiaslange392]

@@flyingvish I bought it on Amazon

[@matroosoft4589]

The last seconds pushed me over the edge to give this video a like. Gave me a good grin, too.

[@wannabewoodsmith4217]

Seriously ...... The world needs more nerds like you. Most people that know me are in awe of my curiosity..... but when it comes to curiosity you are the GOAT !!!!!

[@dolf182]

That's why i love your videos. Nice experiments

[@davidworth4692]

An excellent video, clearly explained with a real-world finding of what was a complex and carefully designed expeiment.

[@Curtis-Randall]

What a great video. I loved the cart at the end. Cheers

[@deemstyle]

This really is a GREAT sponsored video- and your research and testing are remarkable sellers. I've been a big fan of Vornado for years and have many of them. In general, they work very well and can be very quiet. But the Dreo's performance looks exceptional. I think I'll pick up one of these!

[@k.hendrickson8735]

Maybe Vornado has cheapened their manufacturing… I just bought a Vornado at Costco, not on a short neck, but in a square form on TV-like feet, it can point low or upwards. It REALLY moves air, but is so noisy and rattling you can’t hear yourself think. It was only around $40 dollars though. Think I will take it back and apply the $$ towards a Dreo.

[@deemstyle]

@@k.hendrickson8735 I actually DID buy the Dreo- specifically the pedestal one. Quite frankly, it’s the coolest fan I’ve ever owned. It’s extremely quiet and that silly feature of the app allowing you to point it where you want, remotely, is actually really useful. I typically keep it on a combined horizontal and vertical oscillation, but when I’m feeling hot I can open the app and position it on me. You can also tweak the oscillation range horizontally and vertically to specific angles of rotation. I don’t recall this being mentioned on the video, but there’s also a feature called “natural” mode in which the fan randomly speeds up or slows down in order to simulate wind gusts. It’s the craziest thing I’ve ever seen in a fan, and I quite like it; it’s like being outside while inside. In short (I guess not really) I would absolutely buy it again and don’t in any way regret my decision to do so.

[@mickdog2]

wow, I'm impressed yet again

[@zweg1321]

Your video was as informative as usual thank you for making it

[@kirkanos3968]

Man i just found your channel and love it can't stop watching, They need to show this in schools. Guess you could say kinda crazy but can't take all the tiny synthetic junk flying around in the air from mainly tissue, paper towels and kitty hair in my house. To help with it cheaply i get keep pantyhose and put them over a round tower fan, or the cheep green filters from home depot on a box fan just taped on with painters tape. It does help keep the fans and house air cleaner, I know it it cutting the airflow but would love to have some real number:). Another great video

[@geekless]

I just love these videos 💨

[@htiekmahned8859]

Hat off for using the box to measure the more even airflow of the inlet side of fans. Very smart move!

[@eric13hill]

I like how you care about the details of your work.

[@eric13hill]

ps. This series of videos just sold me on buying 4 of those fans. Thanks!

[@Elnufo]

I just love this channel, i really do.

[@TimPiggott]

Hugely entertaining as well as informative 👍🏻 😂

[@Dusk_Daze]

Thanks for the video. This and a few of your others led me to buy the Dreo. It’s fantastic (sorry) and outclassed the my Dyson and Vornado by a lot.

[@DaveChurchill]

Making a video and then contacting the winning company if they want to sponsor is a great business model :D

[@tiitsaul9036]

Thanks nerd. I love your work.

[@SpruceWayne1]

I would love to see you test some of those air movers they use to dry carpets and such. The have similar cfm, but seen to produce lots more thrust.

[@tybellfy5000]

Really enjoying your only fan videos, I’d almost pay a subscription for them. 😂

[@weedwacker1716]

If you get the Lasko fan with the round plastic pivoting frame you get exactly the same motor and blades as the box fan. The round frame is only about a tenth as loud and moves a lot more air than the box version, though.

[@Watchyn_Yarwood]

Woah! I can buy 3 box fans at the farm store for the price of one Dreo Desk fan. Which I have one of that has been running 24/7 for 2 1/2 years. I like air circulation. p.s. I think your videos are great! So interesting, well thought out and I love the data gathering!

[@H3110NU]

I love when you embrace the analytical questions in your head, then develop a scientific way to analyze it.

[@mayoropl1]

Cool experiment! Now it's interesting to see how thrust will change if you remove all (or at least front) protective grid from fans.

[@E_mailMeLater]

Another hit with me😊. I just subscribed.

[@confusingdot]

I like when you add in the factor for how much power you're drawing.

[@donezo1558]

amazing content

[@shintarolin1933]

Your only Fans group exands. I am impressed by the teusting blowing power. Definitely have to check that!! Thank u!

[@gi0rgi0ne]

Great video! Entertaining and useful! :-)

[@thesushifiend]

Very interesting stuff! Perhaps you could test the effect of removing the fans' protection grilles in terms of both thrust and noise?

[@CharredSteak]

For shrouded fans i'd imagine they'd move a little less air. Non shrouded ones might see an increase

[@Inityx]

For the air circulator fans, the grille acts as a stator against the rotor of the blades, and is actually necessary to collect the airflow into a focused jet

[@k.hendrickson8735]

😯 Who knew?? Thank goodness you scienc-y types do what you do!

[@NotaRobot_gif]

This video definitely blows! Nice work!

[@andrewgalbreath2101]

I respect the technique. Compare objectively and then reach out to the winner and see if they'll give you money. Good work

[@wannabewoodsmith4217]

I am a big fan of this content

[@T1nCh0]

I actually trust the brands that let you test their products after you do your things, because MAN you hold no punches in your reviews haha.

[@justinkase1360]

The consistent results of all of your tests are that the cheap fans do best...crazy.

[@gary1anderson]

Thank you for providing us with thrustworthy data.

[@UserNameAnonymous]

I'm glad you checked the one blower, but I'm very curious how a normal sized blower fan would compare.

[@cyphre]

Would love to see more on those window fan types! They seem like a good quiet/compact option, but it's hard to tell if any of them are even good. Literally no real stats available anywhere.

[@andyo-pl]

Thank you for these. I bought the pedestal one and it's great. The app is surprisingly good too. I'm getting the other one soon. I know you tested with 12V but I'm sure you can also use a 20V USB-PD trigger to run it at 20V, and then you can use any USB-PD 60W adapter or even some power banks.

[@bunit8]

Are you getting the dreao desk fan next ? It’s interesting that it is more powerful than the pedestal version

[@andyo-pl]

@@bunit8 I'm not entirely sure I'm getting it, I do think I'd prefer it with a pedestal cause I have no use for a desk fan. I was wondering if I could take off the base like on the pedestal model, and attach it to a stand but now I see that it has electronics in the base, unlike the pedestal model. I do see that they have different blade configurations, 5-blade vs 3 blade. I don't know if it makes any difference, but the blades on the pedestal one have this golf-ball texture to it, more like a curiosity, don't think it would make much of a difference in noise or air movement.

[@GeloNegron]

Since we’re here, I just wanna say I feel like MOST if not all Lasko’s move air really good. It feels strong, fresh & they do a good job. They’re also cheap & have lines that are higher price, they have lots of options… just wonder if anyone else has experienced the same?

[@MCsCreations]

Fascinating indeed! Great testing, Matthias! 😃 Stay safe there with your family! 🖖😊

[@u2bst1nks]

I'd love to see you test blower fans/axial/centrifugal fans like the Lasko U15617, and other ones like it. My understanding is that blowers can produce pretty high velocity streams. I'd love to see how they perform in your tests. I think they'd do well in the thrust test.

[@TheCapt]

When you said fluid dynamics and then talked about the Vornado and Dreo, I couldn't help but notice that their blades resemble more of a boat propeller vs the box fan that resembles a plane propeller.

[@VarionJimmy]

Really like this video. 👍 I’ve just re-discovered electronics/physics after a burn-out, and this video reminded me of how much enjoyment you can have with “simple” things as fans. (Another discovery like this was when I backward-engineered a broken LED tube to build a battery-driven light source for my camera.) I wonder.. could the conclusions (and a fan) in the video be used to build a dust extractor?

[@nickf3242]

I vote yes for thrust ratings on fan packaging! Something else to make it easier for an apples to apples comparison when fan shopping similar to the simulated "nutrition facts" on light bulb packaging added many years ago. I know I've seen a simple version on ceiling fan boxes in the big box home improvement stores.

[@fumthings]

couldn't agree more

[@shakeit995]

but that would just make too much sense from a consumer perspective, we couldnt have that!

[@markushensel7712]

Sehr interessantes Video!

[@ClanMcCormick]

we need a Canadian discount - come on Dreo :)

[@Traderjoe]

I’d be curious to see a comparison between these and ceiling fans regarding air movement

[@k.hendrickson8735]

I don’t think you could ever depend on ceiling fans to actually cool a home; except in the most PERFECT, cool dry climate. As a person living in a sizzlin’ hot climate with ceiling fans in every room of the house, Trust me, they are not much more than auxiliary air movers to help an overburdened central air conditioner between its cycles. At least they’re quiet for the most part.

[@seansean1709]

I like how the arrows on the box point in the direction of the air flow haha.

[@ryann2674]

As someone who doesn't use air conditioning I splurged on the Dreo pedestal because I wanted a quiet fan (instead of the box fan I was using). It's weird to have such a positive opinion on a fan, but I'm really happy with it . And surprisingly all the functions are very useful too. I guess you could say... I'm a Dreo fan-boy now

[@matthiasrandomstuff2221]

my main gripe about the pedestal one is that you need the app to turn on "turbo" mode

[@fairclothjm]

Thanks Matthias, that's really interesting. Here in Texas our attics get hot. I am monitoring mine and when it is 100 F outside the attic gets well above 130 F. So I was considering getting one of those solar attic fans that sits on the roof. But based on this video, it seems like it would be better to put a fan in the attic and point it at my ridge vent. What do you think? It would be interesting to see you do a video on attic air circulation by the way!

[@matthiasrandomstuff2221]

if yor ridge vent is 2'x2', and the fan is rated for the temperatures then yes. My guess is that neither are the case.

[@k.hendrickson8735]

Sounds like a worthwhile experiment…. My big question is: Would an electric fan cool the attic enough to reduce the electricity bill for cooling the home below? 🧐 Or would the power usage needed to run the electric fan in the attic be justified at all?

[@k.hendrickson8735]

There are NO fans in the universe rated for the attic of my home in Phoenix in August.

[@dasmin1135]

I wish You can test the effectiveness of evaporative cooling to lower the temperature and how to make use of it in the most effective way. Also, a DIY evaporative cooling project by using existing fans will be much appreciated. Because, people tend to be cost conscious after energy price increases.

[@RodDiaz]

This video is awesome! im happy I bought the dreo one! Do you have any number on what Watt consumpion is using on every speed?

[@fersuremaybek756]

i would love to see a watt comparison as well that would be interesting.

[@Remmes]

Lol I love the testing shows a winner and then contacting the winner to see if they'd be willing to sponsor, very smart.

[@matthiasrandomstuff2221]

well I had been working with them long before. just I wasn't planning on making this one sponsored.

[@Don.Challenger]

After all is said and done, if the unconstrained results are to their advantage then paying for the privilege is certainly within reason - and presumably having paid, they have the rights to trumpet the results.

[@blobscott]

Very interesting! I have a 1953 Robbins & Meyers 22" 1/2 hp full house window fan that has stamped on its data plate that it moves 3400 cfm, and is certified for this volume by Texas A&M University. It draws a massive draft through all the windows of the 3 floor house when turned on, and it has been in continuous operation for 70 years with a bit of oil every season. I would love to send a Dyson fan (and all other Dyson products) through its steel blades, but of course I won't insult it with such marketing hype junk.

[@k.hendrickson8735]

😂 You had me at ‘1953’ !

[@jameschristiansson3137]

Dreo currently makes no window fans nor any all metal fans of any type. Hopefully one day they will. A fan ought to last a century or more.

[@vmoutsop]

More than I ever wanted to know about fans.

[@deltafactory]

What about CFM/Watt? Wondering if there's an efficiency gain for one design or another.

[@BRISTOLFORCE2009]

I have that same vornado but it’s a pedestal variant (model no: 7803), holy crap on high it’s powerful

[@wilcojuffer5940]

It is so funny how you make a video from fans and also you gif us a lot of data and graficx and so on but I like it also 👍👍😉😉

[@larsaberg6851]

So easy and so good. Measuring thrust. At minute 7 in the video.

[@Studio23Media]

This video broke my brain. I have so many tests to run now. 🤯🤦🏻‍♂️

[@mitchd949]

Coincidentally, I have the same box fan and I've been contemplating making a shroud or circular duct to surround the blade. By having a fairly close fitting shroud the efficiency will be increased over the square box w/rounded corners, therefore I hope to move more air.

[@matthiasrandomstuff2221]

that might actually make it worse

[@jangoofy]

"Lucky for me, this fan has an app" - not something you would typically hear Matthias say 🙂

[@mlindholm]

"Has an app" is an entirely different situation than "requires an app". You can completely ignore app/smart features and it still works just as well, or you can use them for increased convenience.

[@JoseSilveira-newhandleforYT]

Interesting study! So, thrust rules :-)

[@nobody8717]

I'm curious to see the power consumption vs effective thrust of all these fans. That's something to consider. And i wonder how it would compare with the dyson, even though it wasn't performing very well in tests. Performance per watt, I guess.

[@BikeisDusty]

It would be interesting to see a test using this test setup for air filter boxes for

[@theBaebbls]

thanks for your work! i placed the van in the kitchen and let the air blow out. should i open only one window to suck cold air in, your can i open two in different rooms?

[@socas_nic]

It's just sad the Dreo isn't available anywhere except America 😢

[@bigguymarc05]

man should start a fan channel lol, hes got the collection

[@pilotdog68]

Would be interested in you testing a high speed "commercial" metal fan. They have the diameter of a box fan, but more aggressive blade angle and RPM closer to the Vornado style. Many claim 4000-5000 cfm for a 20" fan!

[@Lizlodude]

Ok if Dreo ran that last shot as their advertisement I might actually consider buying one 🤣

[@hansangb]

What en epic ending. I hope the marketing team was paying attention! This is my next fan purchase. I'm happy with the Vornado, it's been more useful than I thought, but it is pretty loud and not as flexible.

[@xuthnet]

The Dreo and Vornado "DC Energy Smart" fans seem to be extremely similar in the fan parts of things. They're both 24V with a simple speed controller module and much the same fan and stator designs. I specifically like the Vornado because it's all analog controls with no "smart" anything and is far less expensive. I ripped out the 120V AC -> 24V DC power supply on mine (vornado) and run it on my DC power system that I use while camping, usually on 12V where it only draws a maximum of about 5W but sometimes I put a boost converter inline to run it at 24V where it push more air but draw about 35W.

[@k.hendrickson8735]

I’m wondering where you’re camping that’s so warm you need a fan? I thought the whole point of camping is that you can move to ‘greener pastures’, or cooler pastures. That was what the entire lifestyle of the American Indian was based upon - moving - and how they survived in the ancient pre USA Southwest.

[@xuthnet]

@@k.hendrickson8735 Depends on why you're going camping. I primarily go camping for lots of events that happen in many different climes and seasons. Anything from camping in winter with sub-zero (F) temperatures to events that occur in 100+ degree weather in the summer. And while I have different tents for these two extremes, I'm still sleeping in a tent none the less.

[@enduringtech822]

Very interesting information considering I am looking to buy a circulator fan. Am I right to say the conclusion is that they work? What would be an ideal way to place them? I am looking to cool a rectangular space, with a door to the balcony which wind doesn't enter. Some said a circulator fan should be oscillating all over, some said to blow it toward the wall or the ceiling. Any advice?

[@tinkerer4]

What if you make wood inserts for the corners of the box fan to make it "ducted"?

[@Neslekkim]

what kind of software do you use for the measurement and graphing?, looks very minimalistic and nice

[@Todd1561]

Pretty sure it's just Microsoft Excel 1997/2000 lol

[@purpleidea]

It would be good to know if these fans return to their previous mode when unplugged and plugged back in-- for all of us that plug them into a wall receptacle that is controlled by a switch on the wall. Thanks

[@matthiasrandomstuff2221]

sadly, none of the black ones do. The white ones are old school no electronics fans though.

[@MrSupaman777]

So what’s the optimal distance for a box fan from a window/ screen door? Can you include distance between two windows/door

[@Sunsetrecordsstudios]

Should also talk about blade pitch and how that also effects the CFM

[@mynintendogamingfeed5208]

Can you also measure in MPH as well? We can see that the CFM is pasted in your awesome data sheet that is easy to understand.

[@Dan-qi4np]

A few years ago you did the experiment of placing the fan at a distance from the widow. These results seem to match.... but weren't you drawing in outside air in that experiment?

[@matthiasrandomstuff2221]

yes, I was. But this year is just too rany. Also, by doing it all indoors, I get much more consistent results

[@vfxforge]

i would be interested to see how a exhaust fan ( for bathrooms ) would perform