I'm studying for the HVAC P.E. and this one video helped me remember almost everything from thermodynamics and start making some headway on practice tests. Great video!
Thank you for sharing the information to us. I do not have any background knowledge before, so there is a lot of things going on when I saw the chart at the first time. After I watch the video and research the chart for our group paper, it makes a lot of sense for me. Though I am still not familiar with this kind of chart, but at least I know what it is about and how can I use it in real life. By learning the psychometric chart, I think students in HVAC can access to this new tool to solve more difficult calculations and find solutions to problems. So in general, this is a very useful and helpful chart and this video illustrate how the chart works.
Thanks, I am going to start up an HVAC company, I just forgot about How to Read a Psychrometric Chart, but this video really helped me. Almost 4 years after Engineering
Ha! You're amazing teaching this subject. Not that is too complicated but it sometimes I get a bit confused and your video turned out to be very handy. It's helping study to my exam. Thank you alot!
Believe it or not, I totally understood the chart in this 7 muinets and was much better than an hour and half in class room, thanks a lot and please keep the way you are of explaining and describing👍
WOW, I must admit im still college and start first hvac job tomorrow, this video is really helping me. I couldnt get my head around these charts at all until this video, THANK YOU.
Thank you very much! My teacher hasn't explained that the dew point temperature is read horizontally and I could't understand its difference from the dry bulb temperature on this chart.
Great video, For the first time I understood enthalpy is the heat or energy with two components, due to sensible part we see drop in DBT & the other is latent used for evaporation & the potential drop in temperature determines how soon or later we will see water condensation, if the drop on DBT to WBT is lower it is closer to 100% relative humidity, if this drop is higher then RH is away from maximum possible 100%. & the DP also goes even lower accordingly, as evident, the gradient of DP is zero or much lower than WBT, & the reduction in depression & DP is also similar. When we hear weather, the weather person mentions RH & Dew Point, rain or no rain, muggy or comfortable, how should we understand weather from DBT, RH, DP, moisture content? Can we use Psychrometric chart to understand if it will rain or not, it will be muggy or not, & how? Could clarify how to use the concepts of DP, RH, moisture content to understand weather?
The knowledge you have shared with us is very interesting & you are great 👍. May I know your profession, is it Mechanical Engineering with focus in HVAC systems design or Architecture? Thanks
When we hear weather, the weather person mentions RH & Dew Point, rain or no rain, muggy or comfortable, how should we understand weather from DBT, RH, DP, moisture content? Can we use Psychrometric chart to understand if it will rain or not, it will be muggy or not, & how? Could clarify how to use the concepts of DP, RH, moisture content to understand weather?
One question. Outside temp is 32F, 80% humidity. Inside temperature is 70F and humidity stands at 40%. Let's say I open the window long enough for the air in the room to be fully replace by the outside air. Then I close the window and turn on the heating until I get 70F again. What will my humidity be? In other words, does this chart help me predict the humidity at a target temperature starting from a certain temp and humidity and adding heat without adding water in the air? Do I basically start from the intersection at 32F and 80% and draw an horizontal line until I hit the 70F vertical line and then read the humidity value on the curves?
By replacing the entire room air with the outside air, the moisture content of the outdoor air is much lower than the starting room condition, even though the outdoor air has a higher relative humidity. The starting room condition (70F/40%RH) has a moisture content of 43.66 Grains/lb. While the outside condition (32F/80%RH) has only 21.19 Grains/lb. If sensible heat only is now applied into the room (e.g. a room convective heater) then this will move in a horizontal straight line from left to right on the psych chart. If the dry bulb temperature increases to 70F, the moisture content will stay the same at 21.19 Gr/lb, but the relative humidity will fall to 19.5%. This assumes that the room does not have any sources of latent load such as people or plants etc that would increase the moisture content of the space while the room is being heated
@@TitusHVAC Thanks for confirming. I've just subscribed to your channel. Greetings from a degree qualified Mechanical Engineer getting a bit rusty having worked in oil and gas for 15 years now :)
+TitusHVAC Thanks a lot. It really helped. I have a query. What if i have the DBT and WBT, and i have to find the enthalpy. I point out the intersection and draw a line to the enthalpy line, but the intersection is arbitrarily in the middle of two specified enthalpy values. How do I find the correct enthalpy value now?
I have a problem. Now assume in a closed room we have found the RH and dry bulb temp. Thus, the specific volume of the room can be found. The specific volume should be constant as the room has a fixed amount of dry air. Now if the room is slightly cooled down then the point marked on the psychrometric chart should be shifted to the left and therefore the specific volume would change according to the chart. How can this be?
Kalana Suraweera the chart assumes a specific pressure. If the room was actually sealed air tight, the pressure would reduce and the chart would change slightly to account for the change in density.
Why is dew point in the weather report many a time at RH less than 100% & it rains. Has it got something to do with pressures like 29.9 inch or less, or wind speed, density or cloud formations, adiabatic cooling due to lower pressures? Thanks I am trying to understand weather, rain & snow
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
1) Starting point 1 is 5C (41F) and 80% RH. The humidity ratio (W) is 30.3 grains/lb (0.0043 lb/lbm-da) and enthalpy is 14.52 Btu/h-lbm. Density of mixture is 0.079 lbm/ft3) 2) Sensible pre-heating (constant humidity ratio) process (a) brings mixture to 55.4F (13C) at point 2 3) Moisture addition (process b) at constant dry bulb brings mixture to 55.4F, 95% RH (W = 62.6 grains or 0.0089 lb/lm-da) 4) Final sensible heating (process c) brings mixture to 77F (25C) and 45% RH (W = 62.6 grains or 0.0089 lb/lbm-da). Enthalpy (h) of final mixture is 28.27 Btu/h-lbm.
The volume flow rate specified is 100 m3/min or 3,528 CFM. The mass flow rate (M) in pounds mass per hour can be determined by the following equation: M = FT3/min x density (lbm/ft3) x 60 min/hr = 3,528 x 0.079 x 60 = 16,723 lbm/h The total heat added in Btu/h is equal to M x (h4 - h1) = 16,723 x (28.27 - 14.82) = 225,924 Btu/h or 65.9 kW The water mass added is equal to M x (W4 -W1) = 16,723 x (62.6 - 30.3) =540,153 grains or 77.16 lbs (35 kg)
An hour's worth of a lecture covered in 10 mins. Cool.
I liked it short and concise, I can pause and learn. Please keep it this way! Great style!
It is incredible to fit this subject into 7 minutes, thanks a lot!
I'm studying for the HVAC P.E. and this one video helped me remember almost everything from thermodynamics and start making some headway on practice tests. Great video!
Where my fellow engineers at?
Studying
yaya boi
Fellow engineer here
Im just here physically, mentally im done with engineering :/
@@muhammadsheikh9413 it's all gonna be worth it bro. keep grinding ! :D
Thank you for sharing the information to us. I do not have any background knowledge before, so there is a lot of things going on when I saw the chart at the first time. After I watch the video and research the chart for our group paper, it makes a lot of sense for me. Though I am still not familiar with this kind of chart, but at least I know what it is about and how can I use it in real life. By learning the psychometric chart, I think students in HVAC can access to this new tool to solve more difficult calculations and find solutions to problems. So in general, this is a very useful and helpful chart and this video illustrate how the chart works.
Thanks, I am going to start up an HVAC company, I just forgot about How to Read a Psychrometric Chart, but this video really helped me. Almost 4 years after Engineering
Thank you for making it SO MUCH easier 🌼
Ha! You're amazing teaching this subject. Not that is too complicated but it sometimes I get a bit confused and your video turned out to be very handy. It's helping study to my exam.
Thank you alot!
Believe it or not, I totally understood the chart in this 7 muinets and was much better than an hour and half in class room, thanks a lot and please keep the way you are of explaining and describing👍
This was wonderful. Thank you!
This really helps. Thanks a lot for your support
WOW, I must admit im still college and start first hvac job tomorrow, this video is really helping me. I couldnt get my head around these charts at all until this video, THANK YOU.
I'm glad they helped :-) Have a great weekend!
Very helpful explanation of how to use a psychrometric chart!!
Thank you, you totally saved my day!
Very precised...thanks a lot.My Professor just provided us the slide and a short lecture on it that was tough for me to capture then.Keep this up
Extremely useful video! Thank you.
Thanks for sharing! Gotta try it with my exercise...
Thank you very much! My teacher hasn't explained that the dew point temperature is read horizontally and I could't understand its difference from the dry bulb temperature on this chart.
Thank you ! Helped out a lot.
Amazingly helpful video!
My professor couldn't explain it to me within half an hour, and here is 7 minute video and i understand everything.
Thank you very much for creating this video.
This is great. Thank you for the video
subscribed! you are a great assistant to the books!
Very well done. Thank you!
Thanks a lot! It turned out to be very useful; I study architecture and I was having a hard time with this chart...
Great summary! Thank you!!!
Thanks and relatively cool, figuratively and absolutely!
outstanding lady... thanks for your help
Many thanks for your information . it was perfect .
it's really cool! thanks a lot!
simply amazing
Nice, i have stay awake at 1am just to finish my report about humidity. Thanks you for explaining
Great video,
For the first time I understood enthalpy is the heat or energy with two components, due to sensible part we see drop in DBT & the other is latent used for evaporation & the potential drop in temperature determines how soon or later we will see water condensation, if the drop on DBT to WBT is lower it is closer to 100% relative humidity, if this drop is higher then RH is away from maximum possible 100%. & the DP also goes even lower accordingly, as evident, the gradient of DP is zero or much lower than WBT, & the reduction in depression & DP is also similar.
When we hear weather, the weather person mentions RH & Dew Point, rain or no rain, muggy or comfortable, how should we understand weather from DBT, RH, DP, moisture content?
Can we use Psychrometric chart to understand if it will rain or not, it will be muggy or not, & how?
Could clarify how to use the concepts of DP, RH, moisture content to understand weather?
Very useful! Thank you
Thanks a lot for this great video. Came in very handy just before the exams :-)
Thank you!
literal queen
Thanks for this video Bro!I just learned something new, Good job!!!
Can you help me solve the problems
Thanks so much it really help me alot.
Thank you Titus hvac for learn me Psychrometric chart.
pinaki biswas mlm
THANK YOU SO MUCH!!!!
The knowledge you have shared with us is very interesting & you are great 👍.
May I know your profession, is it Mechanical Engineering with focus in HVAC systems design or Architecture? Thanks
Thank you for your cool video.
very helpful video!!
You savved my life thanks from poland
You're welcome!
Pls link sand ,I want to join your FB,Instagram,what's app group , it is best advice and any exam
Well done. Go ahead
awesome video... now let's all use international units - IU, in all countries... :P
Thanks a lot!!!!!!
When we hear weather, the weather person mentions RH & Dew Point, rain or no rain, muggy or comfortable, how should we understand weather from DBT, RH, DP, moisture content?
Can we use Psychrometric chart to understand if it will rain or not, it will be muggy or not, & how?
Could clarify how to use the concepts of DP, RH, moisture content to understand weather?
thank you mam for your good teaching.
Thanx v. Helpful
Thank u so much
oh thank you very much..tomorrow is my exam and you have solved my problem
Great, thanks
Apart from my mum this lady is the best
if two intersection point is out of graph can we find other physical properties?
very nicely explained
thnx,. that's informative ...
Amazing
Thank you alot for your excellent toutrial, Please I need the graph colored in pdf form if you can?
I'm a little confused. I tried your example on the chart in my book and got slightly different numbers.
Is this a standard chart?
Great !
Perfect.
Thankyou!
Thank you. Very helpful.
hi cute girl..what,s up?....
thank you.
thankyou so much
Thanks a lot
thank you..
thanks helps heaps :)
Awesome
Simplified.... Nice...
thanks!
it was really useful
Thanks
Good job Madame
Omg I finally get it haha!!
One question. Outside temp is 32F, 80% humidity. Inside temperature is 70F and humidity stands at 40%. Let's say I open the window long enough for the air in the room to be fully replace by the outside air. Then I close the window and turn on the heating until I get 70F again. What will my humidity be? In other words, does this chart help me predict the humidity at a target temperature starting from a certain temp and humidity and adding heat without adding water in the air? Do I basically start from the intersection at 32F and 80% and draw an horizontal line until I hit the 70F vertical line and then read the humidity value on the curves?
By replacing the entire room air with the outside air, the moisture content of the outdoor air is much lower than the starting room condition, even though the outdoor air has a higher relative humidity. The starting room condition (70F/40%RH) has a moisture content of 43.66 Grains/lb. While the outside condition (32F/80%RH) has only 21.19 Grains/lb. If sensible heat only is now applied into the room (e.g. a room convective heater) then this will move in a horizontal straight line from left to right on the psych chart. If the dry bulb temperature increases to 70F, the moisture content will stay the same at 21.19 Gr/lb, but the relative humidity will fall to 19.5%. This assumes that the room does not have any sources of latent load such as people or plants etc that would increase the moisture content of the space while the room is being heated
@@TitusHVAC Thanks for confirming. I've just subscribed to your channel. Greetings from a degree qualified Mechanical Engineer getting a bit rusty having worked in oil and gas for 15 years now :)
screenflicker1, sorry, I often forget to slow down when I talk. Thanks for the reminder.
+TitusHVAC Thanks a lot. It really helped.
I have a query. What if i have the DBT and WBT, and i have to find the enthalpy. I point out the intersection and draw a line to the enthalpy line, but the intersection is arbitrarily in the middle of two specified enthalpy values. How do I find the correct enthalpy value now?
If you fall between two lines, you can interpolate the value.
I have a problem. Now assume in a closed room we have found the RH and dry bulb temp. Thus, the specific volume of the room can be found. The specific volume should be constant as the room has a fixed amount of dry air. Now if the room is slightly cooled down then the point marked on the psychrometric chart should be shifted to the left and therefore the specific volume would change according to the chart. How can this be?
Kalana Suraweera the chart assumes a specific pressure. If the room was actually sealed air tight, the pressure would reduce and the chart would change slightly to account for the change in density.
thanx you
very informative
Thx sir
When you in med school but you gotta know how to use this coz humidity's a bitch in a hot day and can give you a heatstroke.
thanks fam.
These units are wild lmao
Why is dew point in the weather report many a time at RH less than 100% & it rains. Has it got something to do with pressures like 29.9 inch or less, or wind speed, density or cloud formations, adiabatic cooling due to lower pressures?
Thanks
I am trying to understand weather, rain & snow
Because liquid water falling through the air (rain) is different than the amount of water vapor in the air.
Because the rain is originating in clouds at a much higher elevation, rather than fog at ground level.
It was more clear and help full
how to calcuclate humid heat?
Thank you so much, could you sent to me a psychometric chart.
Thank you very much , this was very helpful
can you pls post the link for the psychometric chart used in the video?
www.titus-hvac.com/file/11849/fc_guidelines2018.pdf - page B71
little too fast but great break down of info. Thank you!
really thanks.. for tutorial... mam...
what's the difference between absolute humidity and specific humidity?
It's the same thing
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
1) Starting point 1 is 5C (41F) and 80% RH. The humidity ratio (W) is 30.3 grains/lb (0.0043 lb/lbm-da) and enthalpy is 14.52 Btu/h-lbm. Density of mixture is 0.079 lbm/ft3)
2) Sensible pre-heating (constant humidity ratio) process (a) brings mixture to 55.4F (13C) at point 2
3) Moisture addition (process b) at constant dry bulb brings mixture to 55.4F, 95% RH (W = 62.6 grains or 0.0089 lb/lm-da)
4) Final sensible heating (process c) brings mixture to 77F (25C) and 45% RH (W = 62.6 grains or 0.0089 lb/lbm-da). Enthalpy (h) of final mixture is 28.27 Btu/h-lbm.
The volume flow rate specified is 100 m3/min or 3,528 CFM. The mass flow rate (M) in pounds mass per hour can be determined by the following equation:
M = FT3/min x density (lbm/ft3) x 60 min/hr = 3,528 x 0.079 x 60 = 16,723 lbm/h
The total heat added in Btu/h is equal to M x (h4 - h1) = 16,723 x (28.27 - 14.82) = 225,924 Btu/h or 65.9 kW
The water mass added is equal to M x (W4 -W1) = 16,723 x (62.6 - 30.3) =540,153 grains or 77.16 lbs (35 kg)
realy very easy than calculations
good