You all need to figure out UA-cam's algorithm because this video was buried. I watched many many videos of professors describing the psychrometric chart. They were good and they made sense. But this video has great production value and you obviously put a lot of time into it. I appreciate it. More people need to see it.
@@CAPTIVEAIRE This video was top noch! I'm not in the industry, but it was great to get a better understanding of how the equipment in a space functions :)
Hands down this video explaining physcrometrics is by far the best I’ve seen. Another Johnson Controls tech here, well until a few months back. I now find myself in a different part of the world where humidity control is a very big deal. This video has helped me brush up on the theory a great deal. Thank you CaptiveAir 👍🏻
I really appreciated this video and found it extremely helpful! However, I noticed a significant ERROR regarding wind towers (wind catchers). While the video mentions that they were made by the Egyptians, it's important to clarify that wind catchers, also known as "Badgirs," actually originated in Iran and have been a traditional architectural element in Persian architecture for centuries. They are also found in other Middle Eastern countries, including Egypt, but their invention is credited to Iran. I am surprised that a great video like this made this huge mistake! I hope this can be corrected for accuracy. Thank you for the great content!
I bought a 9th edition Cengage textbook for myself to help become a better tech. It sat for three months and I finally cracked it. First handful of pages I grabbed opened up to the Psychrometric chart and I was immediately horrified, anxiety riddled, and super excited. I spent 45 minutes trying to figure out how to read it - then realized I didn’t know what enthalpy, moisture grains, or even what WB TRULY measured just how to read a differential. This video has made me a better tech in 45 minutes, able to confidently begin actually understanding my psychrometers, as well as be able to accurately use the paychrometric chart. I’ve been doing service going in four years, and these are the questions that even the old blood can’t really go into as they don’t see it as necessary in residential. Well, news flash - residential isn’t where I plan to retire 💪🏼
I'm glad you got something out of the video! And I've experienced the same in many fields, it's common to only "know what you need to know." But others like you and myself like to learn the why, and I find it helpful in many ways. Thanks for the comment, German Tabor (filmmaker).
Even though this video is commercial I’d definitely recommend any student struggling with chart to watch it from very start till the end. Thank’s for a great production and awesome professional technician! Good luck to you and your business! I have processes engineering exam in 10 hours, wish me luck!
This channel really has to be brought to everyone’s attention. I start school in May and just trying to get a brief explanation of the things I’ll see and this video is absolutely so informative. I appreciate videos/channels like this because they help people like me who do have a tougher time learning new things. At first I looked up that chart and almost fainted this video gives me all confidence going into the course. P.S the editing on this video and everything on your channel is beyond exceptional. Thank you!!!
I work for a hyperscale data center provider. I always share these videos with our internal clients (construction, electrical, sales, etc) because they are based. Great job my goodman!
@@CAPTIVEAIRE Mechanical Engineer. Went from Consulting side to Client side. My day-to-day is reviewing designs, working with EORs, many meetings, and also getting to create new standards for our designs. I LOVE this job.
This was excellent in addition to Psycrometrics Without Tears book. As an installer/tech, it opened my eyes to the processes I work with and makes me far better at my work.
Excellent. I particularly liked the inclusion of the discussion about saturation and how it happens. Additional points of interest: Could also mention that the relative humidity (RH) *is* the ratio of the current water content relative to the saturation water content up and down the 'dry' air line (i.e. that it's got that differentiator called 'bulb', not 'air' to the temperature). The fact that the RH lines look curved doesn't stop it being 'linear' when viewed as tick marks up/down the 'dry' air line (calling it 'dry' air can be confusing when you have 100% RH saturated dry air !) The water content of air (and by implications fabrics and sponge fills) shown in the Box Store example can also be extended to aircraft like the 747 which gains extra weight when left idle for a long time and looses weight (better flying) after the internal air conditioning reduces the RH and removes the excess water. I also missed the distinction between the constant wet bulb lines and the enthalpy lines, which IIUC, are not quite the same!
Mass of water in building 12:00 Inthalpy 13:07 comfort zone 22:24 differences beetween peak sensible and latent cooling 35:22 cooling process with reheat and without reheat 41:10 Economizers 43:11
I have been studying psychometrics for the ARE and this is some of the best content I have come across. I love your videos and the way you explain these topics. Thank you so much! ❤
Excellent video. I've suggested it to all our young mechanical engineers. The only issue I have is that "condensate" is a noun and "condense" is a verb. Minor issue for sure but I cant unhear it.
Great explanation of the different psychrometric phenomenon and use of climate design data. My suggestion would be also mention bypass factor as it seems that was the only core concept missing without getting too complicated with designs dealing with fresh air. Bypass factor affects evaporator coil size for a given flow rate. 1-BF= (Tair,in-Tair,out)/(Tair,in-Tcoil,dew point). it also helps in relating psychrometric phenomenon with refrigeration cycle. high ventilation applications typically have small BF.
Another extremely informative video from you guys. You've explained the subject matter way better than what my professor did in my UNI years. If I've seen this video right after graduation, I'd probably pursue an HVAC career as a mechanical engineer. Now thanks to this video, I feel like I missed half of my life due to missing the thing that I really wanted as professional. It's not too late though. Thank you very much.
Amazing video! The visuals you created make the explanations much easier to understand. Also, Bill presents the information so clearly. Printed off a chart for myself and found it very easy to understand + follow along with the video. Thank you!
Spectacular material. Two things that I think worth mention. The chart gives the enthalpy value at saturation, so correction factor is needed. And the charts are plotted for a specific pressure. Please correct me if Im wrong. I know that maybe you didnt mention that for simplicity in the explanation. Thank you for a great video!
Thanks for your feedback SharlsRS. Yes, sometimes we leave some stuff out purposely, sometimes it slips through, yours are very good points nonetheless.
Wow! These videos are amazing! I've been an engineer for nearly a decade now, and these are by far the best videos I've ever found in this industry. Please keep up the great work! I'll be forwarding these videos to my team for sure. Thank you so much for all of the work and production value you put into these videos. Did I mention this video was incredible 😄
I wish we would remove all the governmental regulations around efficiency and get back to decently priced equipment. People in my area are going back to window units because of the rapid cost increases. Units used to easily last over twenty years, I'm still pulling out old 50 year old Yorks. It seems that this time frame is getting less and less, now it's closer to 12-15 years before replacement and quadruple the cost. With all the electronics there are many more failure points. I'm all for advancement but we've taken it to the extreme. We will soon be pricing ourselves out of a job. Great video by the way.
Great Video, one of the best and I have watched a ton over the years. I agree with the last comment. I watch videos like this all of the time and I only discovered this about a week ago.
Great video clips about psychrometric chart, however cooling tower is from Iran (not Egypt) and photo shown in 21:57 is the cooling tower in Yazd, Iran.
Amazing information anyone can understand from A to Z, thank you so much for Educating us. We wish you and you team to achieve all the greatest success.❤❤❤❤
I live in Arizona where the design humidity is negative. Introducing outside air could be used to reheat and modulate the comfort conditions (instead of hot gas reheat). Question: Has anyone taken advantage of this with a simple OSA damper and a smart control? This is especially relevant to homeowners with oversized equipment are stuck in discomfort and the waste associated with compressor short cycling
Sit as service maintenance provider in New Delhi for last 2 year....but not a single HVAC teacher doesn't teach like you studied...s..can I convert another language....
I have a couple questions. Great video BTW! 1. does reheat defeat the purpose of supplying colder air to achieve the setpoint? 2. Although during sensible heating the humidity ratio stays the same, the RH% decreases. Would that create a feeling of increased dryness since the body loses moisture more easily?
Great questions. We have a video on load calculations that may be helpful to give more context to this here ua-cam.com/video/0YCyJ1bQ3qo/v-deo.html 1. Yes in a way. The thing is, we generally want a discharge temperature when cooling no lower than 55°F (there are exceptions). This is for comfort purposes, as colder air would feel too cold to the people in the building. So typically equipment is sized based on 55°F and the corresponding airflow CFM to ensure that in peak conditions this still provides enough sensible cooling. However, although sensible loads may be met, 55°F dry bulb also means roughly a 55°F leaving air dew point, and sometimes this isn't enough latent cooling to dehumidify the space to offset latent loads, so we may have to continue cooling the air to say a 48°F as this removes more moisture from the air. But now that discharge may be too cold to be comfortable. It also may mean that, depending on space loads and the sensible heat ratio of the space, we can't really achieve the window of space conditions we want to target. This is where reheat comes in, allowing us to "decouple" in a way how we handle the latent and sensible loads. We can cool the air however low we need to in order to offset latent loads, then reheat to the perfect temperature to ensure the discharge temperature is perfectly matched to the sensible loads. One example of where we may not care too much if we just discharge 48°F air is a kitchen, where the staff may not mind a cooler discharge since they're exposed to so much heat from within the kitchen. We don't have to use reheat, it's just an option that in certain cases allows for more comfort and tighter control over space and discharge conditions. 2. RH% of the leaving air would decrease as you say. But ultimately what we're concerned with is this discharge mixing with the air in the space, and the final mix having the correct temperature and humidity.
what if the temperature is more that we cannot fit in psychrometric chart like. wet bulb temperature is more than 37 degree then how can we put the temperature..
I thought sensible heat is also (convection and conduction energy) and latent is (radiation energy). Shpuldnt kitchen have higher sensible heat? Pls correct me if im wrong
42:33 Another confusion.. The option without a reheat. If there is no reheat, the air leaving the cooling coil is nearly saturated, hence the relative humidity will be almost 100% then it has to be a lot of sensible heat to heat it back up so that the %RH to be around 50.. The question is it even an option to have it without a reheat?
You are correct. Like you said, one of the main factors at play here is the sensible heat ratio of the space itself and what the result will be once the conditioned air mixes with the space. We can adjust our leaving air conditions based on how the space is reacting as well. And yes, there are times when no reheat is absolutely an option. One thing that may clear up your confusion is that, yes, leaving air at near saturation is relatively high humidity, but remember that the moisture content or "absolute humidity" will still be lower as we removed some moisture across the cooling coil. This means we're still overall dehumidifying the space.
@@CAPTIVEAIRE Thank you very much for your responses and for the amazing content! I showed this video to almost everyone on my JCI team. I promise to use this knowledge to make the world a more comfortable and sustainable place!!
20:13 I don’t understand how a process can only be sensible cooling for example. If you are cooling the air that goes through a fan in a duct hence not changing the volume, at some point, it will be below the due point then it’s the dehumidification process..
You're right that it was a bit of a generalization there. What is meant is that most DX systems struggle once the air reaches or is close to saturation temperatures. Other systems with thicker coils and more capacity can keep cooling and removing moisture from the air much more readily, so we start going downwards and continue leftwards on the psychrometric chart.
Many Thanks for explanation. However it should be slower progress for easy understanding. I often stopped video in order to think clearly what you are talking.
You can go to settings (the gear cog) and click on playback speed then select a slower or faster speed based upon your needs at that time. It is a very good option to have!
You all need to figure out UA-cam's algorithm because this video was buried. I watched many many videos of professors describing the psychrometric chart. They were good and they made sense. But this video has great production value and you obviously put a lot of time into it. I appreciate it. More people need to see it.
We're starting to get a little traction but it always helps if you share and spread the word! Thanks for the kind words :)
@@CAPTIVEAIRE This video was top noch! I'm not in the industry, but it was great to get a better understanding of how the equipment in a space functions :)
If it were renamed ' Woke Psychrometric Chart "' everybody would see it
If you focus is not boring ,this is not for lazy ,short videos modern humans ,go to tick too 😂
We need more videos like this .. appreciate more videos especially on HVAC equipment selection using real scenarios
I don't think I have ever learned more from a video. Remarkable job.
Hands down this video explaining physcrometrics is by far the best I’ve seen.
Another Johnson Controls tech here, well until a few months back. I now find myself in a different part of the world where humidity control is a very big deal. This video has helped me brush up on the theory a great deal.
Thank you CaptiveAir 👍🏻
This is one of the best HVAC videos I have ever seen. I work at Johnson Controls and I recommend this to everyone!! Thank you so much!
Wow, thanks! We need more people like you to keep sharing these, haha
This is so underrated ....Thank you !!
I have been using the psych chart for years, but this webinar showed me some new things.
This was an hour well spent.
I really appreciated this video and found it extremely helpful! However, I noticed a significant ERROR regarding wind towers (wind catchers). While the video mentions that they were made by the Egyptians, it's important to clarify that wind catchers, also known as "Badgirs," actually originated in Iran and have been a traditional architectural element in Persian architecture for centuries. They are also found in other Middle Eastern countries, including Egypt, but their invention is credited to Iran. I am surprised that a great video like this made this huge mistake!
I hope this can be corrected for accuracy.
Thank you for the great content!
I bought a 9th edition Cengage textbook for myself to help become a better tech. It sat for three months and I finally cracked it. First handful of pages I grabbed opened up to the Psychrometric chart and I was immediately horrified, anxiety riddled, and super excited. I spent 45 minutes trying to figure out how to read it - then realized I didn’t know what enthalpy, moisture grains, or even what WB TRULY measured just how to read a differential.
This video has made me a better tech in 45 minutes, able to confidently begin actually understanding my psychrometers, as well as be able to accurately use the paychrometric chart.
I’ve been doing service going in four years, and these are the questions that even the old blood can’t really go into as they don’t see it as necessary in residential. Well, news flash - residential isn’t where I plan to retire 💪🏼
I'm glad you got something out of the video! And I've experienced the same in many fields, it's common to only "know what you need to know." But others like you and myself like to learn the why, and I find it helpful in many ways. Thanks for the comment, German Tabor (filmmaker).
Even though this video is commercial I’d definitely recommend any student struggling with chart to watch it from very start till the end. Thank’s for a great production and awesome professional technician! Good luck to you and your business! I have processes engineering exam in 10 hours, wish me luck!
Went over psychrometrics for two weeks in thermo 2. Didn't garner anywhere near the amount of useful info as I did in this 50 mins. Thank you guys!
This channel really has to be brought to everyone’s attention. I start school in May and just trying to get a brief explanation of the things I’ll see and this video is absolutely so informative. I appreciate videos/channels like this because they help people like me who do have a tougher time learning new things. At first I looked up that chart and almost fainted this video gives me all confidence going into the course. P.S the editing on this video and everything on your channel is beyond exceptional. Thank you!!!
I work for a hyperscale data center provider. I always share these videos with our internal clients (construction, electrical, sales, etc) because they are based. Great job my goodman!
That's great to hear! What do you do on your day-to-day, and do you like it?
@@CAPTIVEAIRE Mechanical Engineer. Went from Consulting side to Client side. My day-to-day is reviewing designs, working with EORs, many meetings, and also getting to create new standards for our designs. I LOVE this job.
This was excellent in addition to Psycrometrics Without Tears book. As an installer/tech, it opened my eyes to the processes I work with and makes me far better at my work.
Excellent. I particularly liked the inclusion of the discussion about saturation and how it happens.
Additional points of interest:
Could also mention that the relative humidity (RH) *is* the ratio of the current water content relative to the saturation water content up and down the 'dry' air line (i.e. that it's got that differentiator called 'bulb', not 'air' to the temperature). The fact that the RH lines look curved doesn't stop it being 'linear' when viewed as tick marks up/down the 'dry' air line (calling it 'dry' air can be confusing when you have 100% RH saturated dry air !)
The water content of air (and by implications fabrics and sponge fills) shown in the Box Store example can also be extended to aircraft like the 747 which gains extra weight when left idle for a long time and looses weight (better flying) after the internal air conditioning reduces the RH and removes the excess water.
I also missed the distinction between the constant wet bulb lines and the enthalpy lines, which IIUC, are not quite the same!
There has never been a more useful video for a more obscure topic. I can't believe something like this exists. Unbelievably useful.
Thank you, I'm glad it's useful. - German
Mass of water in building 12:00
Inthalpy 13:07
comfort zone 22:24
differences beetween peak sensible and latent cooling 35:22
cooling process with reheat and without reheat 41:10
Economizers 43:11
We also list timestamps in our description, if that helps. Thanks!
I have been studying psychometrics for the ARE and this is some of the best content I have come across. I love your videos and the way you explain these topics. Thank you so much! ❤
I’m not even half way through this video but I had to stop to comment because I’m learning so much, thank you from a random in 🇬🇧
Thank you for such a clear-headed outline of psychometric charts! This video is the best resource I've run across yet
This video is amazing! I've stopped the video several times to dive deep...Thank you for sharing.
it is a fantastic video, solved 10+ questions I have for 6-7 years of being a mechanical engineer.
Thanks!
Really the best explanation of psychrometrics I have ever seen.
Perfect. As a mechanical engineer, I really enjoyed it.
Agree. Best hvac video I have seen.
100% Going to just send them your videos when my interns get too annoying!
Much Needed video for Psychrometry
Thanks a lot
Great video! I am currently learning thermodynamics and was puzzled by humid air, but thanks to this video i get it now.
Best video for psychrometric chart ever!
This is a fantastic study on the psychrometric chart.
This video is criminally underrated. The amount of production quality is top notch. I enjoyed and learned throughout the video. Thank you!
Much appreciated!
Excellent video. I've suggested it to all our young mechanical engineers. The only issue I have is that "condensate" is a noun and "condense" is a verb. Minor issue for sure but I cant unhear it.
Damn Bill, u know why i am here. I am taking my PE exam soon. Fantastic video for me to refresh and re-learn what i missed.
This taught me a lot. Thank you.
Glad it helped. Thanks for watching!
One of the best videos on Psychrometrics. Good job 👍🏼.
Great explanation of the different psychrometric phenomenon and use of climate design data. My suggestion would be also mention bypass factor as it seems that was the only core concept missing without getting too complicated with designs dealing with fresh air. Bypass factor affects evaporator coil size for a given flow rate. 1-BF= (Tair,in-Tair,out)/(Tair,in-Tcoil,dew point). it also helps in relating psychrometric phenomenon with refrigeration cycle. high ventilation applications typically have small BF.
Another extremely informative video from you guys. You've explained the subject matter way better than what my professor did in my UNI years. If I've seen this video right after graduation, I'd probably pursue an HVAC career as a mechanical engineer. Now thanks to this video, I feel like I missed half of my life due to missing the thing that I really wanted as professional. It's not too late though. Thank you very much.
Amazing video! The visuals you created make the explanations much easier to understand. Also, Bill presents the information so clearly. Printed off a chart for myself and found it very easy to understand + follow along with the video. Thank you!
Yet to see a top quality video on this subject as this. Good job CaptiveAire
Spectacular material.
Two things that I think worth mention.
The chart gives the enthalpy value at saturation, so correction factor is needed.
And the charts are plotted for a specific pressure.
Please correct me if Im wrong.
I know that maybe you didnt mention that for simplicity in the explanation.
Thank you for a great video!
Thanks for your feedback SharlsRS. Yes, sometimes we leave some stuff out purposely, sometimes it slips through, yours are very good points nonetheless.
Wow! These videos are amazing! I've been an engineer for nearly a decade now, and these are by far the best videos I've ever found in this industry. Please keep up the great work! I'll be forwarding these videos to my team for sure. Thank you so much for all of the work and production value you put into these videos. Did I mention this video was incredible 😄
One of best videos I’ve found on the subject, and I’m only half way through!
This is seriously a brilliant video, it cleared a lot of my doubts. Thanks a lot for the time and effort you put into this.
That's the goal, thanks for sharing!
I wish we would remove all the governmental regulations around efficiency and get back to decently priced equipment. People in my area are going back to window units because of the rapid cost increases. Units used to easily last over twenty years, I'm still pulling out old 50 year old Yorks. It seems that this time frame is getting less and less, now it's closer to 12-15 years before replacement and quadruple the cost. With all the electronics there are many more failure points. I'm all for advancement but we've taken it to the extreme. We will soon be pricing ourselves out of a job.
Great video by the way.
Great Video, one of the best and I have watched a ton over the years. I agree with the last comment. I watch videos like this all of the time and I only discovered this about a week ago.
Thank you so much
amazing work! wish if had knew this vid back when i am in uni, beside that i never know tony soprano the gangsta is also a gangistavta HVAC
Beautiful video. Thank you guys.
Thank you for the video. It is brilliant!
exceptional video... great info on HVAC design
Thank you. This is one of the best I have seen.
thank you so much. this is best explained video ever nake on ph diagram. it helps me a lot
This is pure gold ❤
Thank you 🤗 for this
Good, i need dynamic excel sheet to enter data of my sensors to see if i have a right comfortable zone
It's good to see Tony Soprano is getting decent work.
Wonderful video. Very well explained.
Condensate is a noun. Condense is a verb. Water vapor doesn't "condensate", it "condenses" (verb). The resulting liquid is called condensate (noun).
You're correct, we'll get it right next time!
"Condensate" could also be used in a verb form.
Great video clips about psychrometric chart, however cooling tower is from Iran (not Egypt) and photo shown in 21:57 is the cooling tower in Yazd, Iran.
We will make sure to get this right in future videos. Thank you for the comment.
INCREDIBLE video. thank you
Glad you enjoyed it!
amazing. Thank you very much!
Amazing information anyone can understand from A to Z, thank you so much for Educating us. We wish you and you team to achieve all the greatest success.❤❤❤❤
This is the masterclass.
such a beautiful explanation ! thanks a 12,000 BTU/H.
not sure why this doesnt pop up when you search psychrometrics.
You're welcome a ton!
It is great video I ever seen in my carrier, could you explain more about the reheat Kw calculation. Thanks.
I live in Arizona where the design humidity is negative. Introducing outside air could be used to reheat and modulate the comfort conditions (instead of hot gas reheat).
Question: Has anyone taken advantage of this with a simple OSA damper and a smart control? This is especially relevant to homeowners with oversized equipment are stuck in discomfort and the waste associated with compressor short cycling
Best hvac video out there
That's the most awesome video i have ever seen
Love it! Very informative. Thank you for producing this video.
Thanks for the great video 🙏👍
Excellent Work
Great video, thank you
Agree with all the comments here, what a great video for what can be a pretty dry subject. Will be sharing! Any chance of an SI version? 😉
Good suggestion, we will try adding SI equivalents for future videos.
GREAT VIDEO
Is this something that is important to home HVAC or for industrial, like using chillers?
Thank you so much!
Great Vid . UK Engineer.
Great videos.✍🏻
Awesome video!!!
Thanks sir
From sudan sent my regards
Appreciate information....
I understand this
Mission accomplished
Great, great and great!
In the calculation of sensible and latent heat, aren't the temperatures supposed to be absolute?
Thank you
How could we affect and control vapor pressure inside a closed space (like in a walk in fridge)?
Sit as service maintenance provider in New Delhi for last 2 year....but not a single HVAC teacher doesn't teach like you studied...s..can I convert another language....
Best video ever! Bravo
Great vedio indeed 👍
I have a couple questions. Great video BTW!
1. does reheat defeat the purpose of supplying colder air to achieve the setpoint?
2. Although during sensible heating the humidity ratio stays the same, the RH% decreases. Would that create a feeling of increased dryness since the body loses moisture more easily?
Great questions. We have a video on load calculations that may be helpful to give more context to this here ua-cam.com/video/0YCyJ1bQ3qo/v-deo.html
1. Yes in a way. The thing is, we generally want a discharge temperature when cooling no lower than 55°F (there are exceptions). This is for comfort purposes, as colder air would feel too cold to the people in the building. So typically equipment is sized based on 55°F and the corresponding airflow CFM to ensure that in peak conditions this still provides enough sensible cooling. However, although sensible loads may be met, 55°F dry bulb also means roughly a 55°F leaving air dew point, and sometimes this isn't enough latent cooling to dehumidify the space to offset latent loads, so we may have to continue cooling the air to say a 48°F as this removes more moisture from the air. But now that discharge may be too cold to be comfortable. It also may mean that, depending on space loads and the sensible heat ratio of the space, we can't really achieve the window of space conditions we want to target. This is where reheat comes in, allowing us to "decouple" in a way how we handle the latent and sensible loads. We can cool the air however low we need to in order to offset latent loads, then reheat to the perfect temperature to ensure the discharge temperature is perfectly matched to the sensible loads. One example of where we may not care too much if we just discharge 48°F air is a kitchen, where the staff may not mind a cooler discharge since they're exposed to so much heat from within the kitchen. We don't have to use reheat, it's just an option that in certain cases allows for more comfort and tighter control over space and discharge conditions.
2. RH% of the leaving air would decrease as you say. But ultimately what we're concerned with is this discharge mixing with the air in the space, and the final mix having the correct temperature and humidity.
thank you for the explanation!@@CAPTIVEAIRE
Awesome 👌
Very helpful
what if the temperature is more that we cannot fit in psychrometric chart like. wet bulb temperature is more than 37 degree then how can we put the temperature..
I thought sensible heat is also (convection and conduction energy) and latent is (radiation energy). Shpuldnt kitchen have higher sensible heat? Pls correct me if im wrong
could you please tell me the name of the instructor speakes to uss in the vedio i neeed to read his books and follow him
The main presenter is Bill Griffin. Thanks!
Very good.
42:33 Another confusion.. The option without a reheat. If there is no reheat, the air leaving the cooling coil is nearly saturated, hence the relative humidity will be almost 100% then it has to be a lot of sensible heat to heat it back up so that the %RH to be around 50.. The question is it even an option to have it without a reheat?
You are correct. Like you said, one of the main factors at play here is the sensible heat ratio of the space itself and what the result will be once the conditioned air mixes with the space. We can adjust our leaving air conditions based on how the space is reacting as well. And yes, there are times when no reheat is absolutely an option. One thing that may clear up your confusion is that, yes, leaving air at near saturation is relatively high humidity, but remember that the moisture content or "absolute humidity" will still be lower as we removed some moisture across the cooling coil. This means we're still overall dehumidifying the space.
@@CAPTIVEAIRE Thank you very much for your responses and for the amazing content! I showed this video to almost everyone on my JCI team. I promise to use this knowledge to make the world a more comfortable and sustainable place!!
20:13 I don’t understand how a process can only be sensible cooling for example. If you are cooling the air that goes through a fan in a duct hence not changing the volume, at some point, it will be below the due point then it’s the dehumidification process..
You're right that it was a bit of a generalization there. What is meant is that most DX systems struggle once the air reaches or is close to saturation temperatures. Other systems with thicker coils and more capacity can keep cooling and removing moisture from the air much more readily, so we start going downwards and continue leftwards on the psychrometric chart.
Many Thanks for explanation. However it should be slower progress for easy understanding. I often stopped video in order to think clearly what you are talking.
Thank you for your feedback!
You can go to settings (the gear cog) and click on playback speed then select a slower or faster speed based upon your needs at that time. It is a very good option to have!
👌🏻👌🏻