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!
After watching endless of TH-cam 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
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!
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!
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.
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 :)
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
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..
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.
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.
TH-cam 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.
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?
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.
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.
Download and laminate a chart. The Insight Partners chart is real nice, because it has the index point on it so you can calculate your sensible heat ratio (SHR)
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
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
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?
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.
@@TECTubefilms How to set humidity on NEST th-cam.com/video/7YTk_AzJ6fg/w-d-xo.html Nest Thermostat - How To Set Up a Fan Schedule th-cam.com/video/K4uuIbwLw5w/w-d-xo.html
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.
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.
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
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.
Back when the video was made you used to be able to get them online from the Carrier Bookstore, but they closed that site. You can, however, still get them from your local Carrier distributor.
Would this help ? >> [www.google.com/url?sa=t&source=web&rct=j&url=www.ashrae.org/File%2520Library/Technical%2520Resources/Bookstore/UP3/SI-1.pdf&ved=2ahUKEwj02oyn0YruAhVL7XMBHUtwARAQFjAAegQIARAB&usg=AOvVaw0bMgvpCZtGI6bOrFbE3gmO]
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!
Same here lol
Same here guys.... I hope you both are doing well in your exams cause i suck😂
@@ΣτεφανοςΑλεξοπουλος-τ7τ οοο Έλληνας. Σε ποια σχολή εισαι;
@@aggelosmard491 Χημικών Μηχανικών ΑΠΘ φίλε εσύ ;
Industrial Hygiene here.
This guy is excellent!!!! I wish he was my professor for thermodynamics!!!!
After watching endless of TH-cam 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
Best and most informative video on TH-cam regarding psychometric charts. Great job!
Sir, You are a great teacher. Your lecture was short, derived logically one after another and to the point!
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!
Thanks for sharing comprehensive information on this topic. Excellent
Thanks for the great video. Appreciate your time!
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!
Text Book is so confusing, rather watch You Tube. I almost complete the engineering textbook, but it does not work well.
Really well-spoken and understandable thank you!
Very informative, great delivery and well put together. Thank you so much.
All of the video tutorial are very informative 👍 thanks for sharing your knowledge ♥️🇵🇭
Thank you for explaining this psychometric chart so well ! ❤❤❤❤
this is helpful for the architecture folks studying for the PDD exam. Thank you.
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.
awesome explanation of the psychrometric chart!
We watced this today in my class . I was confused as shit till I saw this video thanks.
no bs straight to the point, very useful video thanks
Vrey good
Great presentation….you made it easy to comprehend 👍🏾👍🏾
This was an amazing introduction! Thank you
Very good clear description. Thanks.
Damn this guy's way of explaining is awesome.
Well-presented and very educational for highly technical person and for a lay-man like myself. Thank you sir. Great presentation. Liked it.
Your sense of humor is interesting
Awesome video! Was reading about this in my plumbing book. Now I understand it! Great explanation!
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 :)
Awesome video! Thank you for the clarity, super helpful.
very very good explaining and examples. thanks
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!
Really good presentation, thanks!
Well explained thnaks Robbie Lawler.
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
Excellent video, very descriptive. Thank you!
God, i have to watch this video for a homework but im afraid to fall in love, this guy is so charming xD
We do believe that is how he courted his wife back in the day... the love language of psychrometrics
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..
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
Great video. Very easy to follow.
Thank you for your explanation! My professor was having trouble teaching us this material without confusing us. 😅
This man is a master
this was quality explanation....
Thanks! very informative, keep them coming.
Sir! Thank you for the explanation.
Going to be reviewing this for my WRT course exam thanks mate
same reason that I'm viewing lol
Great video thanks!
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.
Perfect lesson. Thanks
Amazing, thanks for the video !
very clear explanation. Big thanks! :)
Great info. video. Thanks.
Great Video. thank you very much!
Could I get e version of psychometric chart please ？
Good explanation. thank you!
yo who watching before an exam?
Did you pass?!?! :o
Luis Torres got an A-
Martian Buddy Aw nice dood
Well said thank you.
You are awesome man.
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.
TH-cam 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.
Great explanation.
Great video sir.
Great explanation!
Awesome !
You're mentioned you were giving psychrometric chart how do I go about getting one
Nice explanation 👍
Thanks Tyler 1
Thanks!! Can you explain what the vapor pressure in inches of mercury means and how to use it?
Awesome video Thinks
Thanks a lot!
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?
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.
Great job 👍
Thank You.
Great job here in laymans terms!
At dew point temperature the condensation begins.
How can I get one of those charts? Thank you! Brian
Very helpful thanks
Can you explain section 7:45. On saturation curve? On how it will condense at 30% RH
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.
Love the thumbnail, thank you!
very good info!!
😮❤ I'd like to have 1 of those charts.
Download and laminate a chart. The Insight Partners chart is real nice, because it has the index point on it so you can calculate your sensible heat ratio (SHR)
great video
easy to understand.
Very nice!
Have "future training modules" been made for moving along the chart to change temperature and humidity?
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
How can I get a copy? On your example of the window. Adding humidity to 30% why will it condense?
Awsome, tnx🙏
Fantastic presentation! Do you have any more of the charts?
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
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
www.engineeringtoolbox.com/docs/documents/816/psychrometric_chart_29inHg.pdf
thank you
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?
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.
@@TECTubefilms Thks for the pointer. I'm on it like stink on pooh-pooh ;)
@@TECTubefilms How to set humidity on NEST th-cam.com/video/7YTk_AzJ6fg/w-d-xo.html
Nest Thermostat - How To Set Up a Fan Schedule th-cam.com/video/K4uuIbwLw5w/w-d-xo.html
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.
We bet Ryan has not used metric units since college!
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.
Vapour pressure is where
Thanks!
Exceptional
Is there a link for the Psychometric chart?
You can find it in manual of tropical housing by koeinsberg and a free pdf in form of ppt is available in internet
Can i get a laminated chart ?
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
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.
I want a psychrometric chart
Very good
Would love to get a psychometric chart. Great channel, thank you very much.
Back when the video was made you used to be able to get them online from the Carrier Bookstore, but they closed that site. You can, however, still get them from your local Carrier distributor.
Would this help ? >> [www.google.com/url?sa=t&source=web&rct=j&url=www.ashrae.org/File%2520Library/Technical%2520Resources/Bookstore/UP3/SI-1.pdf&ved=2ahUKEwj02oyn0YruAhVL7XMBHUtwARAQFjAAegQIARAB&usg=AOvVaw0bMgvpCZtGI6bOrFbE3gmO]
Thanks
Great vid :D