FYI for the pressure gauge I used it did not need a pressure differential to measure the pressure. So that is not the reason it didn’t change. I’ve used this one many times inside my vacuum chamber and it works great.

@edyeduard4368

6 ай бұрын

The presure dosen't play a roll here, beaucause the fridge it's not a seal chamber, there is a smal hole in the fridge to evacuate the water from the auto defreeze function in to a tray in the back of the fridge. I think the seal acts like a momentary spring some how end you gave to overcome that spring force first!

@ScienceDude-ux7ug

6 ай бұрын

I was able to measure my freezer using an OMRON D6F-PH5050AD4 sensor. I put the result on hackaday. The project title is hrv, and the user is sciencedude1990.

@gelo1238

6 ай бұрын

@@edyeduard4368 Spring force?...

@eksboks148

6 ай бұрын

​@@edyeduard4368did you watch the video? Not like in a rude way, you seem to be telling him what he said in the start of the video

@ChurchOfThought

6 ай бұрын

It'd be nice to see the small difference reliably just to be sure we have the right explanation. Ala Steve Mould and Electroboom, explanations can get thorny, the chain link one 🔗🖇️ ahh 😅

If your freezer DOESN'T do this, it probably means the seal is bad, and it is wasting energy due to warm air entering all the time.

@robbbbery

6 ай бұрын

Uh oh, mine doesn't! Did older freezers do it? I don't remember noticing it growing up, only as an adult.

@Lucius_Chiaraviglio

6 ай бұрын

@@robbbbery I don't know about that particular unit, but I do know that in the lab where I work we have a -80 C freezer (a LOT colder than a home freezer) that did this when it was new, and it even had a giant screw on the left side that you could unscrew to let air in to break the vacuum. But then as it got older it didn't do this any more, and now it builds up ice inside like cracy, like the other older freezers. I even got service to try to replace the gasket, but that didn't get it back to its new state.

@adi11246

6 ай бұрын

Yeah, even my freezer has this problem. It's quite old, though.

@MontyCantsin

6 ай бұрын

Or you have a good valve connecting the inside to the outside

@Lucius_Chiaraviglio

6 ай бұрын

@@MontyCantsin That was the purpose of the giant screw on the left side of our Panasonic Health Care -80 `C freezer where I work, and when it was new, you had to use this to be able to open the door again after closing it. But later on, the seals got bad, and you didn't need to use it, even after we had the seals serviced.

This seems like a vid someone would make during the pandemic. Trapped at home, looks around their flat, "Okay... what science can I do HERE?"

@towerofresonance4877

7 ай бұрын

People like action lab are the people that lead to the greatest inventions...from their "flat"

@generalingwer4341

7 ай бұрын

Well maybe but science is all around us🙂

@Nir_Ban

7 ай бұрын

Flashbacks 💀💥💥💥

@ozziegillion9049

7 ай бұрын

😂😂😂

@planerdude88

7 ай бұрын

​@@towerofresonance4877yeah I'm with you on the "flat" who says flat? Fuckin British man.

I’m amazed that the interior air temperature drops that quickly. I’ve however experienced this same phenomenon in reverse but when using a microwave oven to heat a dish of food in a food container with a gasketed lid. For example, pop the lid tabs but leave the lid in place, then heat the food as normal and remove the dish from the microwave. Once removed you can then watch the lid concave as its being sucked into what I call a reverse vacuum and it’s impossible to pry the lid apart from the dish without breaking something lol. To remedy, ya gotta put the dish back into the microwave and reheat for 30 seconds or so. To avoid the issue from occurring, you gotta break the seal as you’ve already mentioned by placing a paper towel sheet between the lid and dish, and with the lid in place, your microwave oven’s interior remains clean with no food splatter 😂.

@TheActionLab

7 ай бұрын

That is mostly due to the water vapor condensing more than the air cooling down. As I mentioned at the end condensations can make crazy changes in pressure almost instantly

@Speeder84XL

7 ай бұрын

The interior of the freezer it self and all the food and frozen stuff in there have way more mass than the volume of air inside and doesn't move by convection and get replaced by warmer mass from outside, like the air. So for the short durations the door is normally open, it will stay at almost the same temperature as it was before the door was opened. Once the door is closed again, all those cold surfaces will very quickly cool down the warmer air that got inside again. I did actually experience the same thing truly in reverse for a big electric furnace that I built for metal/glass melting and stuff (as it was electric, it didn't need an exhaust like a gas furnace and was pretty much like a closed box). Which I made a hole in the front of the door of, to get some ventilation and to be able to watch into it, without the need to open the door every time. That turned out to be quite dangerous. Because every time the door was open, the hot air inside got replaced by cold air from the outside - then when the door was closed again, the air inside heated up quickly and expanded, causing jet of air that was up to 1250°C, to blow out thru that hole, haha.

@ProjectPhysX

7 ай бұрын

​@@TheActionLabYou can actually measure the pressure drop with the super accurate barometer of your smartphone! There is this free "phyphox" app that lets you log data from the sensors of the phone. I measured it with my fridge, it's about 1.5 hPa pressure drop within 1 second after closing the door. Equilibrating pressure takes another 5 or so seconds.

@IIISentorIII

7 ай бұрын

@@Speeder84XL Sounds like fun times 😁😅

@bagnon

7 ай бұрын

@@TheActionLab I think the Bernoulli effect also plays a major role where closing the door forces some air out before it shuts completely.

I love how The Action Lab makes videos answering questions that we were asking ourselves in our minds before. Thanks man!

@anteshell

4 ай бұрын

I agree. This is good channel for uneducated to get already munched up and complete answers without having to use one's head to try and apply pre-existing knowledge on practical setting.

The sheer power of pressure-based suction honestly amazes me, how can such a miniscule drop in pressure as the one in the freezer example create *not only* a noticeable effect, but one that TRIPLES the force required to open the freezer door?

@jay2ssrstt

7 ай бұрын

The answer is surface area is multiplicative so what doesn't appear to be a huge change in area actually has a very large effect. Try this same experiment with the smaller freezer door on top of most fridge/freezer units and it is far less noticeable. We also don't seem to think about the actual air pressure very often, probably because it's invisible and we are just so used to it but there is around 6000 miles of atmosphere sitting on us at all times. If you actually start to compare 14.7 PSI atmospheric pressure vs other pressurized systems you realize it's actually a fairly decent amount of force.

@brendanberry7403

6 ай бұрын

Can't remember exactly but it's something like 8-10psi in a house is deadly and will blow your windows out meanwhile you can spray them down with 1500psi pressure washer and do no damage.

I’ve gone my entire life just thinking I was significantly weaker on the second pull 😂😅 great explainer video!

@jonathanc2536

7 ай бұрын

there's no way you actually thought that right?

@leafy_5

7 ай бұрын

@@jonathanc2536 🤣😂 there’s no way you actually thought I thought that right?

@raqqafeller152

7 ай бұрын

⁠​⁠@@leafy_5there’s no way you actually thought that he thought you thought that right?

@KPoWasTaken

6 ай бұрын

​@@raqqafeller152 there's no way you thought that he thought that he thought that he thought that, right?

@AshCid84

6 ай бұрын

Both can be and are true. 🫠

I always liked observing bubbles forming on wine glasses when you place them on the kitchen counter after washing them and before drying. The hot glass heats up the air trapped inside, causing it to expand and "bubble out" to equalize pressure. Once the glass cools down, so will the trapped air, causing it to contract again, creating bubbles, but this time on the inside of the glass

@trucid2

7 ай бұрын

Once in a while I do that to a plate, completely by accident, and it starts making noise from the bubbles and sliding along the table.

Yo so I'm an HVAC tech and I want to thank you for the food for thought with these videos. I swear watching demos like this help me be better at my job 👍🏾👍🏾

A typical refrigerator has a drain hole connected to a pipe that leads to a container where melted ice collects. Most of the time, when the container is not filled with water, the pressure has to equalize much faster because the drain hole is quite large.

@spelunkerd

6 ай бұрын

You make a good point, air pressure should equalize quickly if that drain tube is not obstructed. If the door is hard to open, I'd inspect and clear that drain of frozen water.

@Lookcatbanana

4 ай бұрын

My fridge’s drain hole turned out clogged. After cleaning it, it’s much easier to open the door.

I've noticed that if i slammed shut the big freezer in our basement it was harder to reopen than it was after slowly closing it. So i thought this phenomena was due to the air squished out of the freezer due to the door being shut too kuch for a short time, which then afterwards would cause a lower pressure inside it.

@MsTyrie

6 ай бұрын

I wonder if slamming the door forced some air through the equilibration tube while slowly closing the door didn't. Good observation!

@MontyCantsin

6 ай бұрын

Was it a chest freezer, i.e. with a door on the top? If so, gentle opening will allow the cold air inside to mostly remain inside, since it is heavier than the outside air.

@neutronenstern.

6 ай бұрын

@@MontyCantsin yes it is, and this actually makes a lot of sence now.

I love the force measuring apparatus, that was hilarious. I thought he was going to get some scientific instrument that I've never heard of before and then he whips out a scale and paper towel holder.

@22Platypus

6 ай бұрын

If you think that’s funny, wait until I tell you it was a plunger!

thank you for answering all these questions!!!

yeah! finally, you got to do a video about this, I've always suspected this but never experimented it

I recently stayed at a beach house that had a vacuum sealed Sub Zero refrigerator and that thing was awesome. Of course I'd never pay $15k for a fridge but apparently some people do. It was smart enough to break the seal when you opened the freezer even after closing it.

@merreborn

7 ай бұрын

You can find a similar feature on mid-range fridges these days -- around the $2k price point. They drop the pressure about 20%. I guess the lower the mass of air in there, the easier it is to chill

I asked about this in the comments at another video, years ago. This is a great answer

You can also see this phenomenon if you have a plastic bottle with just some ice inside. If you cover the bottle and shake the ice around, it cools the air inside the bottle and the bottle will begin to compress a bit as the cooling air takes up less volume, reducing the pressure inside. When you open the bottle and allow ambient temperature air to enter, it regains its full shape. Then if you close it and shake it, it compresses a bit again.

@alexandermcclure6185

6 ай бұрын

I have seen the opposite happen with a bottle of ice water; When I open it after a long, hot day, it will often spray water (just a few mL) into my face, due to the pressure gradient from the air expanding. I only realized what made it do that until now, but it makes perfect sense once you think about it.

@jerecakes1

5 ай бұрын

​@@alexandermcclure6185with me recently getting an insulated tumbler, yea this happens frequently too lol

I always needed to know this.. thanks bud 🎉

Great video. Perfect illustration for a daily situation.

Really good demonstration. I have wondered about this phenomena for some time now.

ik so love the placement of your sponsors! i will not skip yours like i do so many others much Appreciated!

While the pressure drop inside the freezer is small, pressure gauges typically measure relative to their surrounding atmosphere which is why it didn't change when you shut it in the fridge. To get a true idea you'd need to have the gauge outside the fridge with a (well sealed) tube running into the freezer cavity.

@anteshell

4 ай бұрын

That is, unless the meter have it's own sealed pressure chamber to compare against. On one hand, I have no doubt he did know this and used a correct tool properly, one the other, he's made even worse blunders before so it's possible he just made one another.

It's stronger because the photons from inside the fridge light don't want you to know it'll turn off.

Thanks for answering the question. Kinda had an idea that it worked that way. Always wondered what made the door get sucked in and the noise it made.

Thank you, I always wondered what was happening.

I've been wondering about this for many years. Thank you for answering it.

@waelfadlallah8939

7 ай бұрын

Same here my friend

KZread: He watches anything anything at this point

Would have liked a demo with a non-cooled fridge, running the same open/close test to make more sense and solidify the conclusion, instead of trying to verify the tiny pressure change alone, confirming the conclusion. This would probably rule out? the springy one way rubber seal(bellows?),not adding to the equation. Also, if several trays of hot pastries were let to cool down and see, if that was a terrible mistake?🤯. It might also accidentally, uncover the presence of a hidden one way pressure balancing valve!🧐.Just some 💭♥️👍

@kikixchannel

4 ай бұрын

If the freezer is not turned on (air inside it is the same temperature as the air in the room), then nothing happens at all. You can open and close it repeatedly without any difficulty on either of them. There's no real point in defrosting a freezer (which clearly has a lot of food inside) just to show something like this.

@aware2action

4 ай бұрын

​​@@kikixchannel Finding an empty fridge(any appliance showroom should have many!) should be easier than acquiring a bottle of liquid nitrogen🤔

I’ve always wondered about this! Thanks!! 😃

that's INSANE! Such a tiny change for such a large difference!

I never noticed. Thanks for info

I love this channel.... been watching it for years! Thank you!

OMG! Loved the plunger and scale. Your the best.

Oh, thanks for explaining! I observed this effect and although I was annoyed by it, I didn't realize what's going on.

I notice that effect with my refrigerator also. I wondered why. Now i know. Thanks.

I always thought its just me using up all of my strength to open it the first time and then not having enough for the second one. Thanks for the explaination, now I know everybody can relate

Wow you explained it really well even better than some teachers at my school

Yes. This happened to me like 3 days ago. Thank you.

Thank you so much for this video .32!years of wondering

Amazing how I just now noticed it for the first time in my life and then exactly after I stumbled upon this video.

THIS MAN BE GIVING THE ANSWERS TO THE QUESTIONS WE ALL SECRETLY WANNA KNOW

Thanks for the video explaining it. I didn't watch it because I am assuming that the cold air that falls out while the door is open gets replaced by room temp air, which is less dense than cold air. So when the room temp air gets trapped and condenses behind the closed door, the volume of air tries to reduce but is kept from doing so by the rigid structure of the refrigerator, therefore offsetting the equilibrium of the air pressure. A mass of warm air has more volume than the same mass of cold air at equal pressure. Open the air tight door, exchange some cold air for warm, close the air tight door, warm air becomes cold, creating a negative pressure effect.

thanks for putting that rock back

At 2:25 After the initial theory for why a vacuum was created inside the freezer, I think that the reason could be that the Refrigerator has a One-Way Valve, and that when the refrigerator is closed, the pressure or movement of air from closing the door shut could cause a valve outlet to spin (kind of like a revolving door), that pushes the air out without letting any back in.

@jasonharrison25

6 ай бұрын

This should testable with a warm or not running freezer

The can made me think of the imploded sub. The speed is insane!

I never had a freezer so I didn't know about this but I realized why this happens pretty quickly after I saw the title. Low-key proud hehe

I have always had this question.

wow great price on the solar charger and love how fast it charges

I've always wondered this! Also, TIL: "equilibrates"

I like the way he ran into an issue with his hypothesis when he failed to measure a pressure difference, then proceeded to present a new hypothesis as to why there was no measurement, presenting calculations that proved that the pressure difference was so small that the gauge was not sensitive enough to measure it.

warm air is less dense, then when it replaces the cold air, then all the stuff in the freezer, cools he air, lowering pressure. Good test of freezer door seal!

Nice, now could you please explain if the light goes out when you close the door or not?

@Krushak8888

7 ай бұрын

It goes out, like older fridges had a v like trigger at the time. My current one has a sensor so ifyou line the doors up when open it'll turn off

@mr_dadik

7 ай бұрын

There is a little guy in the freezer that turns off the light when he sees you close the door

@generalingwer4341

7 ай бұрын

Lol.ive tried to catch mine on,but its to sneeky.🤔

@Ithenna

7 ай бұрын

@@mr_dadik lol

@Ithenna

7 ай бұрын

Mine literally has a button on top that gets depressed when the door is shut. I can turn the light off myself when the fridge is open. Newer fridges probably use a light sensor. Like the type that sends an infrared or some other invisible frequency directly to a detector when closed, and the signal is broken when the door is open, thus triggering the light to turn on.

for some reason, the scale + stick pressure gauge impressed me the most.

Always so interesting 😊

Following your video, I felt like trying an experiment to see if the door seal had anything to do with it: I thought that maybe when the door is closed, with the speed, the seal is compressed, reducing the air volume between the seal and the fridge edge. The rest, I understood both by watching your video and by trying the experiment. Here is the remaining part of the theory: Furthermore, due to the door opening, the air around the seal was heated; waiting a few seconds after closing the door, the air that remained despite the closing speed became cooled, further reducing the remaining volume. Thus, the pressure between the seal and the door became lower. Due to this low pressure, the seal was pressed even more against the walls, preventing air from passing through. Certainly, after waiting a bit, air enters again partly between the seal and the door, making it easy to open the door again. Here's the experiment I conducted: I opened the fridge door and then closed it very gently. I could reopen the door directly without needing to exert more force. However, if I waited a few seconds after gently closing the door, I couldn't easily reopen it. An astonishing phenomenon: after a gentle closure, even if I reopened and closed it with a bit of speed, I could still reopen it without much effort if I didn't wait. I also tried starting by closing the door with some speed, and I noticed that I could also open the door quite easily (the seal of my fridge probably needs to be replaced :)). So, I think that between the two phenomena I mentioned that could tend to reduce the volume, the one that is most at play is the reduction of air volume due to the decrease in temperature between the seal and the walls of the fridge. The other phenomenon is not to be completely ruled out either; if the door is closed with a lot of speed, it might be more significant.

@TheActionLab

7 ай бұрын

I think when you close the door slowly the air that is inside is cooling down before the door even closes all the way so the pressure already equilibrates before you even close the door. But when you close it fast it is already completely closed before the air starts to cool down. So when you close it fast there is a larger air difference.

now i get it!! ty for that...

Without the video even starting I know it’s because of pressure, and if it’s hard you just push in before pulling. Works so well

@The Action Lab You should have used your phone to measure the pressure difference. There are several apps (my personal favorite is the Physics Toolbox Suite). It actually measures pressure down to Pascals! I've measured the pressure differences when you open doors inside of rooms and push other doors. The pressure difference is usually on the order of 10 Pascals, or up to 50 if you push the door quickly.

@cyrilio

7 ай бұрын

Just tried the physics toolbox suite and it’s awesome. Had no idea my phone could make all these measurements so precisely. Thanks for sharing.

@DANGJOS

7 ай бұрын

@@cyrilio Yes, it's amazing! Glad you found it! :)

@jasonharrison25

6 ай бұрын

No barometer sensor on my phone ☹️

I thought it was just my imagination that it was harder to open it the second time. Finally someone is explaining it.

I'm so proud of myself for figuring this out myself one afternoon when I experienced this myself while getting a soda can (and then ice) out of my fridge.😂😂

i love this channel soo much

Now we're asking the big questions

This is super cool!

You should have used a samrtphone's barometer to measure the pressure difference, they're incredibly accurate

Vacuum caused by the warm air losing volume by being chilled. Over time, the vacuum is lost due to imperfect seals.

The phase change science is really cool

I didn't notice that it's harder second time But noticed that. But sometimes notice that it's hard to open sometime

That makes sense

5:15 That's actually kind interesting, the pressure drop seems to accelerate, I'm guessing it's kind of a chain reaction situation, since lower temperatures means slower movement of molecules they start to slow each other down as each of them slows down.

The same effect occurs when you pour hot tea/coffee in an insulated container and let it cool down. My tea flask makes whistling noises a few minutes after I take a sip because outside air is slipping past the seal and making its way inside

As a student in Chemistry, this reminds me of breaking a round bottom flask for heating it while plugged. The plug shot out and the flask dropped. Luckily no one was hurt

For these experiments maybe you could use one of those handheld luggage scales and just use the hook at the door. I've always thought there was a vacuum pump closing the door.

Good stuff.

That's so cool, it's just the difference between warm air and cold air and the slight vacuum is spread out over the whole door so it's barely noticeable but still significant..... This is such a cool world. 😁👍 Edit: I'd like test if one of those batteries would be able to power an ebike or electric vehicle. 😮❤

Idk why but I noticed this a long time ago but never thought about the science

Great video!

Cool video! Thanks. You should make a video about why blocked ears / ear barotrauma happens when taking off in an airplane, and why pumps still can't counter act this phenomenon.

@CineSoar

6 ай бұрын

On the ground, the air trapped behind the eardrum by blocked eusatcian tubes, is equal to the surrounding air pressure. As the plane gains altitude, the external pressure decreases, while the trapped pressure remains, pushing out painfully on the flexible eardrum. The aircraft pumps some pressure into the cabin, but only to the equivalent of 10,000 feet (reasonable for people who are not exerting themselves much, while being low enough that the aircraft doesn’t have to be built more like a submarine), which is quite a bit lower than the pressure at sea level.

@DoNotEatPoo

6 ай бұрын

And also why parents should be arrested for child abuse when taking infants on flights. If you ever wonder why they power scream and never shut up, is because the intense pain they're experiencing.

Excellent

I have never seen this before, with any freezers I have had, or had seen at a friends house(not that I open and close my friends freezer) before.

Finally my question has been answered...

That was great. I'm wondering about the online pressure simulators you were talking about. Can you provide some site info please? Thanks

As someone who worked at target I'm very familiar with this the longer the walk in freezer is open the harder it is going to be to open again. that's how that one drunk girl died in the walk in freezer she was too drunk and weak to open it again you really have to put your body into it to open it or just wait for it to get cold again.

Not sure if it applies to that digital gauge, but usually pressure gauges have to be outside what they are measuring since they use the air they are surrounded by as reference.

@kutsen39

7 ай бұрын

I'd be interested to see if he could set up his vacuum chamber with the pressure gauge measuring the outside air. So the spigot is in atmosphere, but the reference portion is in the chamber. What would it show?

@FishSomething

7 ай бұрын

@@kutsen39 assuming it's using a reference the way I would expect, it would read an equivalent positive pressure when in vacuum. Would be interesting to see - could compare a digital and mechanical one too.

I thought I was crazy.....great video

DUDE! I was going to do a video on this a few months ago and never did (other channel of course)! haha ... very good man - good stuff :D

There's a reason commercial walk-in freezers have a heated (so frost doesn't develop on it and freeze it) two pressure relief baffle system.

So, no second beer genius in there!!

Some laboratory deep freezers have a vent. When you close the door, you can hear the air rush in.

Great video 👍🔝

Mad respect for you sir...from india

Hehe, I like how when you open the freezer, that reveals a product from here, about two states below, in Utah, where you used to live: Creamies ice milk bars!🍦

We have a -80C (-112F) freezer at work that I semi-frequently use. With such an extreme temperature, it can rise pretty rapidly whenever we open it and we really don't want things inside to get warmer than -75C. Therefore when I'm putting samples in the -80 it'll be like: open freezer -> grab container -> close freezer -> load sample into container-> Open freezer -> put container back. But like the second time I open that motherfucker I have to use my whole body and brace my foot against the pallet it's attached to and it STILL won't open sometimes. This whole time I thought I was crazy, or doing something wrong on the second open, but NO I'm just a victim of physics

@Danuxsy

5 ай бұрын

aren't we all victims of physics though? 😥😥

This science is interesting.

3:05 I have a slight issue with the way you calculated the pressure difference needed to create that force on the door. Your wooden rod was placed on the door handle of a door that was rotating on a hinge. The force on the door needed to create an equivalent counter torque to prevent the door from rotating will actually be larger than that.

@IIISentorIII

7 ай бұрын

Jesus, get yourself a girlfriend or go Mountain-biking ASAP!

@EGRJ

7 ай бұрын

@@IIISentorIII This is literally a channel by and for physics nerds.

@DANGJOS

7 ай бұрын

@@IIISentorIII No thanks

@TheRealDrJoey

7 ай бұрын

I don't think the point was to get an accurate measure, but more to demonstrate that there was a definite difference, and, at east by that kinda kooky method of measuring it, it took 3 times the force.

@DANGJOS

7 ай бұрын

@@TheRealDrJoey Yes, fair enough. I just remember him actually calculating the pressure difference necessary to get that force difference, so that's why I mentioned that. I may be mistaken in what he was saying.

That power generator/battery was really cool. But I would never use it. It has all of these cool features but I might use it once a year😂

My daughter is always moaning how hard the freezer door is to open as if it's my fault. Thanks for this, I'll be showing her this immediately.

Good video!

one of my freezers won't do that until l adjust the seal on the bottom of the door, it works best when it gets that seal

So it was exactly what I just guessed would happen. I'm now proud of myself

I loved the syringe demo. seeing a pressure gauge go down works in principle but seeing the syringe going in and out really hits a home run in my brain. I already had a correct hypothesis at the start of the video but seeing that syringe was definitely worth a watch.