Wet bulb temperature - why & when is it used?

A wet bulb temperatures is the same as a "regular" temperature, but we wrap a wet rag around the bottom of the thermometer to measure it. But why the heck do we even do this? When is it useful?
Shout out to Themba Khumalo for my awesome artwork.
thembakhumaloa...
/ thembakhumalo_art_
/ themba-khumalo-art-540...
00:00 We know HOW, but WHY?
00:43 What we know from just a wet bulb
02:03 Wet bulbs are lower than dry bulbs
04:28 Dry & humid days
06:28 Relative & absolute humidity
07:30 Cooling towers
Process with Pat is the place to come for perspective and to ask stupid questions. I want you to leave more knowledgeable, confident, motivated, and most importantly, curious. I also want to invigorate a field that seems tired and uninspiring, at least if you get your perspective from internet forums. These are not lectures. This is a place for you to leave thinking “Oh! That’s why...”
This channel is not only for chemical engineers - anyone who works with processes should be able to find something of value here.
#ProcessEngineering
#ChemicalEngineering
#ProcesswithPat

[@tajammulkha_n6791]

As a chm engg. student m pretty impressed, how he explained it clearly while most books fail to do so.

[@ProcesswithPat]

I really appreciate that!

[@renungreningtyas3823]

so true, thanks Pat

[@klaytonickinson]

I'm a 3rd yr civil engineering student. These youtube videos are more efficient than 90% of my professors! Thanks to talented people running educational channels like this one. Thank you!

[@xse345]

Haha .. The last part is quite accurate. I dont remember how many times I have explained to my non-engineer friends how to differntiate cooling towers and stacks.

[@ProcesswithPat]

Just a little joke, but there is truth to it, right!?

[@xiaoyingfu6004]

HIs last point was interesting!

[@snusmumriken232]

Cooling towers scare me now because of the journalism. They look scary and big and smoky

[@Checkmate_Bro7]

You’re the hero we need but don’t deserve

[@ProcesswithPat]

Basically a shitty Batman, huh? Pretty useless in a fight, and instead of money I have some knowledge about pumps XD

[@Checkmate_Bro7]

@@ProcesswithPat Haha! But all jokes aside, as a new engineer, I find your videos incredibly useful. I want you to know that your hard work is greatly appreciated, and I am looking forward to more videos in the future.

[@CharliMorganMusic]

Saturation Point is a book that mentions this a lot. It's fun. Adrian Tchaikovsky

[@okjuuuuuudy]

the part about the pictures of cooling towers being used in news about pollution is so true

[@aaaaa1957]

Thanks, that’s the best explanation I’ve run across. 45 years ago while serving in the Marines part of my duty would be traveling through the hills in Virginia taking Wet Bulb readings for the base. The stations were near the Harriet Jets landing pads. Thanks again

[@pwrofmusic]

Im an oil tanker captain. This was the basics of what i had to do. During my training many years ago. Well explained.

[@cwj9202]

Excellent description. Here the dry western part of USA, swamp coolers are utilized to cool houses, but in the humid South with its high humidity, the same swamp coolers don't function as well as on the west coast.

[@Mikeofindy]

Explained far easier to understand compared to what was taught to me in my HVAC schooling.

[@hassangoudarzifgf931]

Amazing expression. Thx. English is my third language but I understand it 100% .

[@Neal_Schier]

Good lecture. Wet bulb temp, as I was taught, can never be greater than the dry bulb. Or at least the dew point can never greater than the ambient temperature.

[@Yoyo-qi5kx]

just studied wet and dry bulb painfully and have a look on youtube I'm so happy to see someone can explain this so well thanks for saving my day i appreciated!

[@TGFMusic]

Thank you for this. I have no idea why it’s so hard to wrap my head around dew point/RH/WB/DB but I do and this helped with that part of it.

[@zeyadib1211]

This is the best explanation ever for wbt! you should return to making these awesome videos.

[@mikefochtman7164]

Worked at power plants over the years, often training new folks. As an exercise, I would sometimes ask them how much water it takes to keep the cooling water system filled. At first, some would suggest very little since most of the water is returned from the cooling tower back to the plant. But if you have a large plant (say, 3000 MWthermal) and it's running about 40% efficiency, then about 1800 MWthermal is being rejected into the cooling tower. That's on the order of 800 kg/s evaporating. In terms for us in the US, that's over 12000 gallons per minute!!! And yes, the effectiveness varies a lot with the daily weather, which affects the return temperature of the water by quite a bit. Great video, with some great explanation.

[@mikefochtman7164]

@dougadams9419 I never said ANYTHING about 'reactor water', don't know where you got that idea. And BTW, BWR's boil the reactor coolant directly and there are losses in any steam cycle. And in a BWR, the 'reactor water' IS the steam cycle. Cooling towers are used in many fossil plants as well. Bascially ANY large steam plant has to reject a lot of heat to the environment and cooling towers are one way of doing that. Look for large fossil fueled plants and those too are near water sources.

[@lendssadiasa4814]

im glad you exist in YT. you really explained it well

[@razhanmatipano3468]

This is probably the best explanation I've heard for dry & wet bulb and I work in the AC industry as a mechanical engineer.

[@dscottn1016]

Awesome video. You should be a teacher. Great video. I'm an hvac technician. I love your explanation.

[@ChemEngWeekly]

Great concept explanation pat! Technical, yet simple and clear, 10/10 would recommend 👍

[@MuhammadAjmal-c3g]

Finally I found KZbin useful and productive

[@CharliMorganMusic]

You gotta check out more of the platform, fam

[@Springer5]

If you're not a professional educator, you should be. Easily the clearest, most effectively presented lesson on WBTs I've ever seen. Thank you.

[@tamjidkabir1543]

Best part is the thermocouple demonstration ❤️❤️

[@saadqadeer7807]

Epic Explanation. Your channel is really underrated!

[@ProcesswithPat]

Thanks man! I’ll keep at it!

[@marau9749]

What a brilliant video. I explored that deep reason for a while. That is exactly what I looked for.

[@IrishSnwbrdr]

Studying for my prelim and I just did not understand my professors explanation in class, this totally cleared it up, thank you

[@ProcesswithPat]

Awesome! That’s why I did it. Best of luck for the prelim Kevin!

[@mikailali5888]

Sir! God bless you. You have done a better job explaining than my PHD professor.

[@chandansangi06]

Cleared my basic concept

[@galaxymist7396]

The shower analogy was SO informative, great video.

[@keithlynch3169]

Great, thanks very much for increasing my understanding!

[@billigerfusel]

First video that provides the explanation why not just what it is. Hats off to you, sir.

[@conniecombs5428]

Thank you. I never make KZbin comments, but this was so helpful and well explained.

[@yefengli9512]

A super clear video explaining the concepts and application of wet bulb temperature. Much appreciated!

[@meetshah2365]

Thank you!! Concept got clear.

[@dp8178]

Kudos to you, this was the only video that explained it simply enough for me to understand!!!

[@spongebobbatteries]

Hello from Puerto Rico. I recently graduated Mech Eng. I loved thermodynamics, and the thermal sciences lab. But I didn't fully understand these concepts. You really brought them home for me with this video. You got a sub

[@ProcesswithPat]

Hey thanks man! I guess where your from you need the concept of wet bulb more than the average person huh? ;) Also, solidarity with your electricity situation, from a South African who faced similar issues!

[@spongebobbatteries]

@@ProcesswithPat indeed... The recent hurricane Fiona and heat waves have got me looking up low cost, off grid solutions for food refrigeration, cooling, clean water, heating, desalinization, etc. Thankfully, people like you make this educational content so we can understand these concepts better.

[@spongebobbatteries]

@@ProcesswithPat thank you for the solidarity. If I may ask, was your situation recent, or was it growing up?. I only know a few things about South Africa + I barely keep up with current global news

[@ProcesswithPat]

@@spongebobbatteries Nah it was mostly in the past. Moved to Denmark around 6 years ago for work. But I still have family &/ friends, so I am commenting more on their situation than my own. And yes, keeping up with what's going on everywhere in the world is impossible. Simply too much. That's why I obsess over my work instead :)

[@suemiller9506]

This was a great explanation and I liked the simple but clear sketches - you made it easy to understand and remember the concept. Also, I enjoyed your final 'trigger' comment - I always wondered about those climate change images of towers spewing something - now I know, they're just cooling towers 'spewing' water vapour.

[@panoskb9405]

What an amazing video one more time! :) We are looking forward to your next videos! :)

[@akshaiambro702]

Conceptual Clarity in your explanation is outstanding...patience is a virtue

[@rev.shannonkimbell-auth6995]

Aha! I get it now. THANK YOU!

[@tunaman2200]

Great job explaining wet bulb! Thank you very much for this!

[@jbragg33]

Cool I finally understood this wet bulb nonsense lol

[@lovelymaheh5105]

Hats off to u sir....great explanation...

[@ibrahimal-saif9322]

This video is just perfect, now I understand the difference

[@muhammadadilabbasi6741]

Super Awesome...elegantly explained

[@Aatir361]

One of the best explanation. a use of Whyyyyyy whyyyyy 👌👌👌👌

[@Krizbonz]

The 'Wet Bulb" just turned on in my brain, finally I understand!!! Thank you (and thanks for the American translations hehe)

[@anshadmnassar]

Discovered your channel nearly. Awesome content and quality. Please do more videos.

[@stevenphiri8041]

I love this channel man. Keep up the good work

[@chavsny1578]

Wow this was very well explained thank you.

[@tensortab8896]

A natural wet bulb thermometer (not physically aspirated) is used in Industrial Hygiene to measure heat stress (along with dry bulb and globe thermometers).

[@prasadadavi6618]

Thank you very much.... 🙏.... I will never and ever forget the concept. ❤️

[@mohamedelbohy8507]

Many Thanks for you detailed explanation

[@seekingrafael5630]

Cheers! Very useful. Much better than just reading the words in my book. :)

[@amiralifouladimehr8144]

I really enjoyed ,it was awesome!

[@ProcesswithPat]

Nice! That’s what it’s there for!

[@joaopinto4616]

Nice punch line. I am not alone in this :D keep the good work

[@snusmumriken232]

This is a goated explanation of this concept thanks bruh

[@irisforgiarinipasini1753]

OMG finally someone that could explain the difference between wet bulb and dry bulb temperature clearly! I really really appreciate it. I understand now! Thank you very much.

[@subomile]

Amazing video Pat!

[@vindee]

Thank you for sharing your knowledge. I hope you are doing well.

[@waqasahmadabasi8693]

Fantastic way of explaining . Got it

[@Smthe-ib3sz]

Absolutely brilliant explanation Sir

[@shantasubedi2636]

Thank you very much ,you really cleared my doubt.

[@jayshridesai6471]

Great explaination.... Please keep going.... A lot more better than the bookish explaination.

[@trishachokshi8414]

I finally get it! Thank you so much for this.

[@ProcesswithPat]

Awesome! That’s why it’s there…

[@LearnEnglishatSusieArcade]

I finally understood. Thank you for the visual input, the practical examples and the clear explanation. If I might, I suggest you to change the title. This video wasn't my first choice because I was looking for an explanation for dry and wet temperature. Thank you again :)

[@nathandaubis819]

ANOTHER SOLID MOMENT IN HISTORY

[@ProcesswithPat]

Seems pretty epic!

[@gelomelo3426]

Super excellent 👏

[@hasir_dh]

amazing video for an HVAC engineer as well

[@chaitanyadesai1101]

An absolute genius....Great job Pat.

[@taxfree4603]

excellent explanation

[@classycashew]

THANK YOU finally an explanation that makes sense. Thank you so much 😭

[@akshaykumardayma4951]

Lovely bro...You are the best teacher.....

[@michaelbruwer4156]

Thank you. Very helpful. Excellently done. Graciously presented.

[@mxcollin95]

Excellent, excellent video! 🤙

[@lekhrajdewangan8491]

That is exactly what I wanted to know. Thankyou so much sir. I am final year mechanical engineering student and I really want to understand its physical significance.

[@mushfiqurrahman8659]

perfectly explained ..after going through multiple youtube videoa. I finally found a perfect explanation

[@HaythamSAtia]

Thank you so much.

[@Ykitten-7]

Excellent

[@kshitijmishra9100]

That is really a fantastic explainaition..... kudos!!!!!!!

[@saradiadas141]

crystal clear explanation ☺

[@malikhassamzahid6301]

simply.. legend❤

[@girishmhatre483]

Most of my concepts related to wet bulb temperature are cleared with this video. Thank you so much sir.

[@ProcesswithPat]

Nice! Make sure to check out the difference between wet bulb and dew point too!

[@vladimirm6908]

Finally proper explanation! Thank you very much for your time and effort!

[@sharayu3410]

Thank you so much for explaining the why thing

[@ProcesswithPat]

Trust me, it wasn’t obvious to me when I was studying… It only came afterwards!

[@niceguy4801]

Thankyou so much sir!

[@Bump2310]

Really nice and easy to understand explanation - thank you! I'd only add that the process doesn't start with water insisting on evaporating on its own. Heat energy moves from our skin or the thermometer bulb to the relatively cooler layer of water (which in turn is cooled quickly by the air temperature which is cooler than skin most of the time) because it has no choice about it (it has to follow the temperature gradient) and that's what makes us feel cooler (heat is being sapped from your skin). Then the increased heat content of that water causes it to evaporate which adds to the cooling effect as the warmed water doesn't stick around to create a new, insulative watery skin at the same temperature as your body.

[@ProcesswithPat]

Hey there! I’ve been thinking about this one for a few days… I’m considering the scenario where you have a bunch of water on a plate with air above it all at the exact same temperature… if you introduce bone dry air, also at the same temperature, the the water will evaporate and cool down the plate, even thought the initiating event wasn’t heat transfer from a hot surface to the cooler water. Bit of a chicken and egg scenario? Not sure…

[@salimakallel6092]

Great explanation Thank you very much it helps a lot !!!!!!!

[@wantedkiller23]

GREAT EXPLNATION! THANKS!

[@davidecasella_]

fire background setup man, fr

[@ryaneads6271]

This was a great video and was exactly what I was looking for. Thank you!

[@sreejijayan4341]

Very well explained

[@Alpen_Blitz]

Well done sir! Please keep up the good work sir. Thnk u!!!

[@esanariam]

Excellent Explanation, Thanks a Lot!!

[@wowmath5691]

Thank you so much you made it so crystal clear

[@ProcesswithPat]

Awesome, that’s why it’s there! Out of interest, was there something you didn’t get before watching? And if so, what was the confusion?

[@rishivardhan9147]

Thnx a lot! all doubts cleared in one shot! Hats off to u, greatttt expln!!!

[@ProcesswithPat]

Glad it helped! If I can ask, what was it that you weren’t sure about? I know it’s often difficult to ask a question when you’re not totally understanding something. What was it here?

[@rishivardhan9147]

@@ProcesswithPat All videos on youtube talked abt the measurement of WBT......ig u r the only one who explained the significance of it and its application on cooling towers!

[@pravinsamgir964]

Thank you. Very well explain....

[@MrUbiquitousTech]

Great video, thank you for sharing.

[@OsmacksO]

Thanks, very helpful.

[@wilnum1]

This was a great video … on point with the information very well understood