How to Read a Psychrometric Chart

[@coryhall5957]

I know this wasn't really its intended purpose, but I'm actually watching this video for my chemical engineering thermodynamics class haha. Great explanation!

[@ramonsanchez7748]

Same here lol

[@ΣτεφανοςΑλεξοπουλος-τ7τ]

Same here guys.... I hope you both are doing well in your exams cause i suck😂

[@aggelosmard491]

@@ΣτεφανοςΑλεξοπουλος-τ7τ οοο Έλληνας. Σε ποια σχολή εισαι;

[@ΣτεφανοςΑλεξοπουλος-τ7τ]

@@aggelosmard491 Χημικών Μηχανικών ΑΠΘ φίλε εσύ ;

[@darrinm486]

Industrial Hygiene here.

[@adamahmed52]

Taking HVAC as an elective for my mech eng bachelors. I have a test in 20 mins and Im prepared but sometimes I mix up the lines in my head as the chart was shown to us recently. Thank you for making it clear and consice :)

[@efravillegas69]

I had to use a psychrometric chart recently and remembered a great video I watched a few years ago. Thankfully, I found it quickly -such a great explanation!

[@chiraagbohra]

This guy is excellent!!!! I wish he was my professor for thermodynamics!!!!

[@yussefab]

After watching endless of KZbin videos about this topic, I finally found this one which in all honesty is the most clear explanation about this chart, thanks to all the people who work on it so hard

[@iAMCobalus]

Best and most informative video on KZbin regarding psychometric charts. Great job!

[@hilldillduck]

Thank you for the explanation! I'm studying for my certified energy manager exam and I think I'm a lot closer to understanding this chart!

[@willemswart1605]

I would have loved to have this guy as the teacher of mech. engineering class in architecture school. Dude's funny and great at explaining an otherwise confusing chart

[@Saint_777]

Great presentation….you made it easy to comprehend 👍🏾👍🏾

[@sandiagocity2753]

Thanks for sharing comprehensive information on this topic. Excellent

[@JaykeSapalaran-iq3qs]

All of the video tutorial are very informative 👍 thanks for sharing your knowledge ♥️🇵🇭

[@koowasha]

Sir, You are a great teacher. Your lecture was short, derived logically one after another and to the point!

[@simeonsond4given75]

Very informative, great delivery and well put together. Thank you so much.

[@gozieerondu1992]

I don't work in HVAC but im taking a MechE course right now that discusses this. Been having trouble reading this chart via textbook, so this lesson was perfect, thanks so much!

[@kathymejillano6429]

Text Book is so confusing, rather watch You Tube. I almost complete the engineering textbook, but it does not work well.

[@BenSmithHuugs]

Thanks for the great video. Appreciate your time!

[@averyyoung8873]

Really well-spoken and understandable thank you!

[@alocin110]

Well-presented and very educational for highly technical person and for a lay-man like myself. Thank you sir. Great presentation. Liked it.

[@jenniferdurhamwong920]

this is helpful for the architecture folks studying for the PDD exam. Thank you.

[@Katprzk]

I am in my second year of my architecture degree and I have a course dedicated to mechanical, electrical and plumbing in commercial buildings. We started looking at these charts the other day and I was so lost. Thank you so much for this video, it helped so much! You are the best. Thanks!

[@ttriffic03]

Yes this guy is good at explaining propertys of air. When i went to the construction college for pre exam prep 2 years they did convey all this info but not as well. Weird thing as a HVAC contractor for ten years I only knew a small few who would use this kind of data when sizing a system for residential homes, then a change with B&Z required it and they were lost for quite a long time they had to learn manual j and D to draw a plan. I made quite a living during these periods.

[@tioluwanielesho1448]

Thank you for explaining this psychometric chart so well ! ❤❤❤❤

[@IceSmash2]

This was an amazing introduction! Thank you

[@thisisblackmesa]

awesome explanation of the psychrometric chart!

[@lanceward7048]

Thought my teacher was calling this the "PSYCHOmetric" chart for like a month, and I didn't have a any reason at all to question the name.

[@salmansabarwal748]

no bs straight to the point, very useful video thanks

[@jollyscaria1922]

Vrey good

[@philipoakley5498]

Great. Would be nice, for some, to start at Relative Humidity section (~6 minutes) , and note the nice big fraction shown in the top left blank area of the chart, and notice that on any vertical 'dry air' temperature line the relative humidity is in nice linear 'tick marks' (going from zero to 100% saturated). And that the way we shift from the current point out to the 'web bulb' (diagonal line) is neatly at right angle to the curves of the relative humidity..

[@davidspevacek2937]

Awesome video! Was reading about this in my plumbing book. Now I understand it! Great explanation!

[@beltusnkwawir2908]

Your sense of humor is interesting

[@bobbritt5904]

IF YOU WANT TO KNOW WHAT THE NUMBERS ON THE Y-AXIS MEAN, READ ON: According to Wikipedia (see LINK1 below) A grain is a unit of measurement of mass, and historically was the mass of a grain of wheat or barley. Apparently, a grain is now defined as 1 grain = 64.79891 milligrams (eq. 1) According to Wikipedia (see LINK2 below) 1 kg = 15432.3487 grains (eq. 2) Therefore 1 g = 15.4323487 grains (eq. 3) In the USA, we measure weight (which is actually force, not mass) in pounds, as in "he weighs 170 lbs". To get a feel for what a "grain" is, we can ask "how many grains in a pound"? There are 453.592 grams in one pound (453.592 g = 1 lb) 1 g = 15.4323487 grains (eq. 3) If we multiply both side of the eq. 3 above by 453.592, we have 453.592 g = 6999.99 (eq. 4) In other words (in round numbers) 1 lb = 7000 grains (eq. 5) So, in this video, the y-axis on the right (which reads 0, 20, 40, 60,...) is "mass of water vapor, measured in grains, divided by mass of dry air, measured in pounds, for a given volume of moist air". The 2nd y-axis on the right (which reads .001, .003, .005,...) is "mass of water vapor divided by mass of dry air, for a given volume of moist air". So it could be "pounds of water per pound of dry air" or "kg of water per kg of dry air". Whenever the presenter says "grains" we could take that number, divide it by 7000, and arrive at pounds. Let's test that out, at 6:00 mins in, we see the "132 gr" arrow is just above 0.19" on the two y-axis's. Let divide 132 by 7000 and we get 0.019 and that's in agreement with his chart, which confirms our understanding!!! LINK1: en.wikipedia.org/wiki/Imperial_and_US_customary_measurement_systems LINK2: en.wikipedia.org/wiki/Grain_(unit) NOTE: If I've made a mistake, reply to this comment and correct it please.

[@TECTubefilms]

KZbin auto-blocked your comment (not sure why... maybe because of the external links). We did not take the time to read your thesis for accuracy, but since you mentioned wheat and barley, Ryan said to go ahead and share your post. He also said to work hops into your next comment somehow.

[@TheClinchMagazine]

Damn this guy's way of explaining is awesome.

[@codypepper94]

Thanks much more clearly explained then engineering professor

[@manickn6819]

Very good clear description. Thanks.

[@aoknives]

Awesome video! Thank you for the clarity, super helpful.

[@pravious]

Great video! Thank you for sharing this information. What's the model number of that Fluke device? I'm interested in getting a digital humidity/temperature meter as precise as possible? I've noticed how the measurements on the sling might be biased by how consistent the person using it is while rotating it, so a digital one could be a solution. Thanks again.

[@tombouie]

I thinks I got it. In a nutshell: Given a Pchart for a specific barometric pressure, the intersection of any two parameter values is a single point on the Pchart. Given a point on the Pchart, all its parameter values on the Pchart can be easily determined. Thks TomB

[@HoodHandyman]

We watced this today in my class . I was confused as shit till I saw this video thanks.

[@masoudsheidaei3415]

very very good explaining and examples. thanks

[@dubemmba9602]

At 8:02 why don’t we have a problem when we lower humidification to 20% since that reduces the dew point temperature? I thought condensation occurs when you go below dew point temperature?

[@TECTubefilms]

Condensation will occur when the dry bulb air temperature of surface in question drops below the dewpoint. In this example, the indoor temperature is fixed at 75F and the window temperature is fixed a 35F. We started with air at 75 db, 23% RH, and 35 dewpoint. We changed the indoor humidity down to 20% so that puts us at 75 db and 31 dewpoint. If you lower the RH (23 down to 20%) with a fixed dry bulb temp (75F), then the dewpoint of the air is lowered to 31. If my window surface is 35 db and my indoor air is 31 dp, then my window is ABOVE my dewpoint and hence no condensation.

[@derrickgarcia303]

Can you explain section 7:45. On saturation curve? On how it will condense at 30% RH

[@TECTubefilms]

That example was 30% RH in the building at the humidistat, not 30% at the cold surface and the point of condensation. In that section of the video we were explaining how the cold window would drop the temperature of the air immediately next to the window (say within an inch of the surface) and as that temp dropped, the RH would rise. As it gets cold enough to raise the RH to 100%, then condensation occurs.

[@freddygill3425]

Great video! Very well explained. You said you were going to mention a little about enthalpy. I was wanting to see that too. Thank you!

[@klaytonickinson]

Thank you for your explanation! My professor was having trouble teaching us this material without confusing us. 😅

[@leemontgomery7914]

Really good presentation, thanks!

[@JohnnyJr396]

Thanks!! Can you explain what the vapor pressure in inches of mercury means and how to use it?

[@europeankid98]

Excellent video, very descriptive. Thank you!

[@chetnarayangyawali6714]

Could I get e version of psychometric chart please ？

[@willi7173]

At dew point temperature the condensation begins.

[@tombouie]

Ryan, I have a question but here's the context 1st: I have force air conditioning for the whole house. But on a whim I ran my portable a/c on dehumifier mode the last few days. !Amazingly it was getting a gallon of condensating a hour! More importantly although the temp was pretty hot, the humidity was pretty comfortable ~%70. It was like being out in the arizona desert in the summer (hot but dry). In a nutshell I want a lot more dehumidified air & a loot less cool air. In the portable a/c unit I assume air is slowly forced over just above freezing evaporator coil thus maxing the dwell time for condensation. Finallllllllllly the question: ?Can I buy a thermostat that will make my whole house force air conditioner be more of a dehumidifer? If not, how can I do it myself?

[@TECTubefilms]

Yes, lots of thermostats use the air conditioner to run a dehumidification mode. This would include some of my favorites, such as ecobee 4 (or 5), Carrier "original" Cor, and Bryant Housewise. Also many stats from Venstar and Honeywell. There are two ways in which these can be used. 1) Cool to Dehumidify: this forces on the Y1 signal if the space is more humid than the dehumidification setpoint... even if the space temp is satisfied. This works with all equipment irregardless of type or brand. 2) Dehumidification Mode of the Equipment: this would turn on the dehum relay of the stat as needed. This relay would be wired to the DH or DEHUM input on the furnace. This will slow the blower down while running the cooling to change the sensible heat ratio and hence optimize the dehumidification ability. It should be pointed out that both of these are different than running a dehumidifier. A dehumidifier is a essentially an air conditioner with one important difference. Both the evaporator coil and the condenser coil are in the occupied space. This means no heat is rejected to the outdoors and instead it is rejected back into the space. This is obviously not energy efficient. Additionally, it does not lower the indoor space temp. So a dehumidifier only dehumidifies, but an air conditioner can cool and dehumidify... and how the stat controls it can help it do one more than the other.

[@tombouie]

@@TECTubefilms Thks for the pointer. I'm on it like stink on pooh-pooh ;)

[@tombouie]

@@TECTubefilms How to set humidity on NEST kzbin.info/www/bejne/bYq3nJJ3r69pnMk Nest Thermostat - How To Set Up a Fan Schedule kzbin.info/www/bejne/gWXYpnyYrLGqa9k

[@asbasf2382]

Well explained thnaks Robbie Lawler.

[@rasheedaqeel]

Great video. Very easy to follow.

[@chrstfer2452]

This was awesome! Thanks so much, ive been trying to grok these charts the past week or so and this helped me get my head around it

[@georgedvojacki9770]

You're mentioned you were giving psychrometric chart how do I go about getting one

[@brianoverstreet7390]

How can I get one of those charts? Thank you! Brian

[@trentjk]

Have "future training modules" been made for moving along the chart to change temperature and humidity?

[@TECTubefilms]

We have not made a short video series, but we do have a 3 hour free training on the Psych chart that does cover that and more. Here is the link to the first 90 minute module of that training - register.gotowebinar.com/register/1045518315942376460

[@amv_pure]

Thanks for the video. What brand and model is that yellow thermograph device you have?

[@TECTubefilms]

Fluke 971

[@amv_pure]

@@TECTubefilms awesome, thanks

[@MegaDee911]

Thanks! very informative, keep them coming.

[@joev.6703]

Fantastic presentation! Do you have any more of the charts?

[@danielafernandez1493]

God, i have to watch this video for a homework but im afraid to fall in love, this guy is so charming xD

[@TECTubefilms]

We do believe that is how he courted his wife back in the day... the love language of psychrometrics

[@MartianBuddy]

yo who watching before an exam?

[@nodice100]

Did you pass?!?! :o

[@MartianBuddy]

Luis Torres got an A-

[@nodice100]

Martian Buddy Aw nice dood

[@mariumali4852]

this was quality explanation....

[@AtliTobiasson]

This man is a master

[@mastablunt]

Going to be reviewing this for my WRT course exam thanks mate

[@BingBong20005]

same reason that I'm viewing lol

[@BostonClipper]

Question: For a given room volume (cuft), if I take two sets of measurements (before, after), measuring dry bulb and relative humidity can I determine the difference in water content? For example: If I measure the volume of a house, record dry bulb and relative humidity, open the windows, record again the dry bulb and relative humidity... a spreadsheet could calculate how many gallons of water have been introduced or removed from the house? It would quantify in a relatable way the effect of opening windows on a "nice morning" only to regret later in the warm afternoon.

[@TECTubefilms]

Theoretically, yes. But you will need more than the psych chart. You can plot your DB & WB state points and use those to find the absolute humidity on the chart. But that is going to tell you how many grains of moisture per pound of dry air. Then you need to calculate how much dry air the volume of that specific house holds. And then how many grains are in a gallon.

[@BostonClipper]

@@TECTubefilms I was going to use 7000 grains per pound and 8.34 pounds per gallon. Therefore 58,380 grains equals one gallon. The volume is no problem. I am a retired architect.

[@TECTubefilms]

@@BostonClipper We were debating here in the office if you were a retired civil engineer or a retired architect. We knew it had to be one with a question like that. LOL

[@BostonClipper]

@@TECTubefilms lol

[@johnmiranda4587]

What is the relation between dewpoint temp & RH? I'm asking because in your 2 examples, for the duct in the ceiling, condensation occurs when the temperature is below the dew point while for the glass, condensation happens when RH goes above the desired RH.

[@TECTubefilms]

Condensation on glass is the same as all materials. If the temperature of the material is below the dewpoint temperature of the air touching the material it will condense.

[@TECTubefilms]

RH and dewpoint are related... they are both lines on the psych chart. The RH lines are the curved ones.

[@derrickgarcia303]

How can I get a copy? On your example of the window. Adding humidity to 30% why will it condense?

[@marklysaplala2689]

very clear explanation. Big thanks! :)

[@mikailali5888]

Sir! Thank you for the explanation.

[@jeremysarver5094]

Great video thanks!

[@rebekahrodriguez4954]

So good and helpful! Thank you!

[@joonfanatic2140]

Amazing, thanks for the video !

[@stopthephilosophicalzombie9017]

I thought specific humidity was grams of water per kilogram of air. Is there another way to measure it with grains as the water unit?

[@TECTubefilms]

Grains is the unit of measure in the US. If you are in another country, you might be using grams.

[@stopthephilosophicalzombie9017]

@@TECTubefilms Thank you. I found the American units version. Fascinating explanation of this chart.

[@floyddavis263]

Is there a link for the Psychometric chart?

[@ztoic7364]

You can find it in manual of tropical housing by koeinsberg and a free pdf in form of ppt is available in internet

[@gooddeedsleadto7499]

I noticed the line coming into the compressor inside the condensing unit has few inches of rubber hose left on it, rest of line is exposed? Is this line going to sweat in the summer, is it going to affect the performance if I don’t replace the broken insulation? And why? Thanks

[@TECTubefilms]

If... or rather when... that line gets below the dewpoint of the ambient air, it will sweat. Yes, missing insulation affects performance, which is why it was originally insulated. A small amount of insulation missing might not affect it much. The more that is missing, the more the customer may notice a higher energy bill or less cooling capacity.

[@konstantinosskourkeas1277]

they done my guy dirty in the thumbnail

[@tonymedici8414]

Great explanation.

[@ebrahimsayed6854]

Great video sir.

[@realtorflores4686]

Hello .. I was wondering if you offer these videos in a dvd set for sell. Basically I’m looking for anything that help a beginner better understand the formulas and graphs in depth. Please let me know.. thanks in advanced.

[@TECTubefilms]

No, we do not sell these videos. We figured putting them on KZbin for free was better.

[@TECTubefilms]

Although, some of these slides that Ryan used were in this video are part of a larger training class that Carrier has. They call it the Technical Development Program (TDP). We have been teaching it as an in-person class for decades and many other Carrier offices do the same. You can also order the workbooks from your Carrier distributor for self-study. There are probably 40 different modules and each is about 4 hours.

[@TECTubefilms]

Here is a good one to start with www.carrier.com/carrieruniversity/en/us/training-courses/courses/abcs-of-air-conditioning/

[@louf7178]

8:42 70F/20% RH? I don't know how you could have (or want) living space that dry !?!

[@TECTubefilms]

It was 72F and 20% RH, but we understand your point. This is pretty common for a midwestern winter. Office spaces are very seldom humidified. Although, if the humidity was higher we could lower the temp in the office and be equally comfortable.

[@louf7178]

@@TECTubefilms Ah, wintertime. It must have been quite cold, and well into the winter season to dry out that low (time for materials to dry out as well, otherwise they keep the space RH a bit higher, longer) (forensic HVAC, LOL). Thanks.

[@TECTubefilms]

@@louf7178 It was the last day of autumn (12/20/17) in the morning in North Aurora, IL. Outdoor temp records show it was between 31 and 35 degrees outside, which is about 5 degrees warmer than the average. It was also only 16 and 25 dewpoint. Because of the outside ventilation air coming through the minimum position on the economizer, we bring in a lot of dry air. Our classroom, which Ryan's office shares a RTU with, was also empty that day so that is 15 to 20 less human humidifiers in the space. LOL

[@louf7178]

@@TECTubefilms That is some recollection. If you looked it up, thankyou.

[@TECTubefilms]

@@louf7178 Haha. We looked it up! Not even sure what we had for lunch over here.

[@chandervideos5082]

Good explanation. thank you!

[@eastudio-K]

Do you have a pdf of the version of the chart you recommend

[@Tarak-ho3xb]

Yes I have

[@indikasanjeewarupasinghe4662]

Great Video. thank you very much!

[@zahidmustafa6368]

Perfect lesson. Thanks

[@richardfossani6421]

Good video, how could I get one of those charts?

[@TECTubefilms]

If you are a HVAC pro in the Chicago area, sign up for one of our classes at www.tecmungo.com/training

[@richardfossani6421]

I am an hvac pro but not in the Chicago area. Is there any other way of getting one besides going to your class?

[@TECTubefilms]

@@richardfossani6421 We order them from Carrier - www.carrier.com/carrieruniversity/en/us/bookstore/

[@TECTubefilms]

@@richardfossani6421 Or your local Carrier rep can get you one

[@richardfossani6421]

My local guy doesn't have one, anyway I could purchase one from you?

[@AjithKumar-lt1sj]

Vapour pressure is where

[@keegankroeger9557]

I need to know how to find grains of moisture per pound using the temp of 85 degrees f with a relative humidity of 60%

[@TECTubefilms]

Find 85 db on the vertical axis and follow the line up to the 60% RH curved line. Make a dot there on your chart. Then read horizontal access to the far right to determine the grains of moisture.

[@hayatullahrahimi4690]

I want a psychrometric chart

[@tavonterrell9396]

@tectubi I would like to get a psychrometric chart how do I get one?

[@Tbm-ov5ky]

do you have a pdf of that chart?

[@mohsinel_obaid6703]

Could someone send me a printable black and white chart pdf.... I've searched online and i don't have much time left for the exam

[@Acontador13]

www.engineeringtoolbox.com/docs/documents/816/psychrometric_chart_29inHg.pdf

[@BBirch]

Nice job. How can I get the software you used in this video?

[@TECTubefilms]

We did not utilize any software in this video (except PowerPoint)

[@i3igpete]

He was using a presentation provided by carrier (the AC manufacturer)

[@shaveenalviz3834]

can i ask a copy of that chart? i badly need a clear copy of that chart for my studies. thank youuuu.

[@TECTubefilms]

You used to be able to order them at www.carrieruniversity.com, but we think now you have to get them from your local Carrier distributor.

[@45KevinG45]

Can i get a laminated chart ?

[@LynneLaRochelle]

Great explanation!

[@bikram4you]

Nice explanation 👍

[@yoyofd]

Thanks how do I get one like that for my shop ? Thanks

[@TECTubefilms]

We give them out at a lot of our live classes including the one that starts next week. www.tecdealer.com/Dealer/TrainClassRegDtl?lngDtl=928&lngCourse=583&WebLink=3

[@aboreza6680]

In an air washer installation, 100 m3/min of air at 5 oC DBT and 80% relative humidity has to be heated and humidified to 25 oC and 45% of relative humidity by the following processes; (a) preheating, (b) adiabatic saturation in a re-circulated air washer up to 95% relative humidity and then (c) reheat to final state. Calculate: 1. total heat added in kW 2. water mass to be provided to the washer and 3. humidifying efficiency of the air washer. You can find solutions to this question

[@eddiesellers8522]

great video. earlier in the video you used to points ambient temp and specific humidity, how did you come up with the specific humidity number?

[@TECTubefilms]

That was just an example of 75F and 60 grains. We could have picked anything in that example. If you were taking field measurements, the easiest two to measure are dry bulb and wet bulb, but once you plot their intersection on the graph, you could then read specific humidity (grains), relative humidity, dew point, enthalpy, etc. on the chart.

[@brianmcdermott2430]

Great info. video. Thanks.

[@gooddeedsleadto7499]

How do we measure the specific humidity? Is it grains of water vapor per pound mass?

[@TECTubefilms]

You will not have the tools to measure this is in the field. Historically folks would field measure dry bulb and wet bulb temps, plot that point on the psych chart, and then read all of the others from that plotted point (specific humidity, dewpoint, relative humidity, enthalpy, etc.).

[@TECTubefilms]

The units are grains of moisture per lb of dry air. Essentially it is a ratio.

[@VISHALMOHAN1993]

You are awesome man.

[@rodel9999]

You explained the chart very well. Hope you could present the metric version of psychrometric chart. That's what we use here in teaching air conditioning course. Thank you sir.

[@TECTubefilms]

We bet Ryan has not used metric units since college!

[@ryanhoger1]

True... it has been well over 20 years since I had used metric on a daily basis. The U.S. is weird. We teach both IP and SI to kids... then in college it is all SI... but then we send you out into the workforce where absolutely no one uses SI. Then every company has to re-train every college kid they hire how to use IP units again. Crazy.