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It's amazing how little people think about the future use compared to ”It's cheaper? Perfect! Just install that one!” or ”Yeah, we can just fix it later.”
It depends on the financial standpoint of a business owner or investor. They may not have enough money right off the bat to pay for the extra ductwork and equipment in more advanced systems. They just want to get the business up and rolling
Dual duct systems were extremely common in the 60s through the 80s in the US. At my university here in Texas, all the original dual duct systems from the 70s are still going, complete with all the ancient mixing boxes, tiny high static hot/cold deck ductwork, pneumatic thermostats, and the enormous custom AHUs literally built into the buildings. Interestingly enough, one of our buildings completed as late as 2008 has a dual duct system. Dave McFarlane has an interesting writeup on old systems called "Retrocommissioning older buildings."
Just a mention that CAV’s are still used in places where the air exchange per hour (ACPH) is required. I work in a decent-size modern hospital and air-turnover is critical to pass inspections.
easily explained video, as always. @4:33 the total flow rate is fixed, but to the individual diffuser, with the help of damper, we can decrease the individual flow rate (e.g. to 3 cubic m/s) although the total flow rate (e.g. 20 cubic m/s) will remain constant, right?
Please make a detailed video about transistors and their uses,types,working and why they are revolutionary invention I know that there are many videos about transistors but your animation and explanation is best 😁
thanks a lot for these learning materials. Maybe just put radius also on the duct work illustrations since these 90 degree designs creates air losses on the system.
As always videos are great. Have you thought about adding a multizone CAV system to your examples? I've been looking for more info about them, but there's not a lot out there. Seems similar to the dual duct system but the individual zone dampers/actuators are at the AHU with multiple ducts feeding the different zones. Thanks!
30 m3/s is a lot of air. Not by any means small ahu can provide that kind of air volume flow. Also, rotating or crossflow heat energy recovery is now day pretty much standard in AHU units. At least here in Finland.
Would a VAV control system also require cooling at the AHU as well as reheating for the VAV box terminals? Is there a substantial difference in this way between CAV and VAV? Or is it solely due to the modulation of air volume (and furthermore, heating) for the individual rooms in a VAV system that saves energy?
@3:53 you are saying that temperature changes in different rooms, but @5:51 you are saying all the rooms receive the same temperature. I don't get it. Is it that normally in CAV, you get same temperature in all rooms but by using inefficient terminal heater/cooler you can get varied temperature?
So I'm curious; if they have to chill the incoming air to a set temperature anyways, then reheat the air at the point of use; why not use a heat pump to simultaneously chill the air coming into the building, and heat air at the point of use?
Crt me if I'm wrong...in this there no separate CAV box like VAV box only the thing is to add on heater or similar to heating unit. So CAV is one type of system which we used early. There is no use of it ..and one more question instead of VAV can we use motorized VFD for the same it can also be control the flow as well by using the thermostat. And why do we need air flow sensor on VAV we were already controlled by thermostat... please clear my doubts ????????
I am back to bother you :) Can you do more motor control? i.e. soft starters? Perhaps some steam plant stuff (high pressure steam), hydraulics, and pneumatics? Diesel generators? New processes vs old processes? Things found in institutions like universities and hospitals, and whether or not they differ from commercial and industrial? Have you considered including a bit more calculation in your videos? Or another channel to connect the visuals with the calculations for the math nerds? MORE MORE GIVE ME MOAAAAAAAR
But I think in CAV system we can regulate the flow rate of air to the room if we will put VCD in room branch. Suppose, you are telling for one room 30m3/min in 13degree is very high, so we can adjust damper and get 20m3/min in 13 degree, and that will be sufficient for room. Where I am wrong, please, explain me
No mention of TAB? Testing, Adjusting, and Balancing that makes the system actually do what its supposed to and where problems might be discovered. Also, You don't adjust the Volume dampers during commissioning. You do that's during TAB by a certified technician that sets total fan speed as well as each diffuser output. Arguably one of the most important parts of commercial HVAC, by making sure that expensive system is doing what it was designed to due.
Just saw this and i puked a bit in my mouth.. we have a CAV system with two machines built in our newly built hotel.. one zone for the guest rooms, one zone for the tiny bar, two guest kitchens, a green room, the only meeting room and the lobby.. so a silent meeting room has the same Volume (sound not air) is present in the meeting room as in the lobby.. then in the summer in the lobby doors are open, upper floors without windows that can be opened and the whole thing can't go below 18°c degrees which are realistically 21°c and then the chiller dies...
This type of system is normally done with a Rootop unit or a furnace. I have designed over 5000 Electrical & Mechanical projects. I am an electrical & mechanical engineer. If they want temperature control I just install a zone damper system. An HRV is usually installed as well. I have never seen this system in a large building. Normally VAV with mixing box at the air handler. Mostly pneumatic controls and hot water rads. I also built myself 100 apartments as of recent. I was the engineer and contractor and I own the buildings. All 100% Electric. No gas. In Canada. I hate gas. It is dangerous and in Manitoba, our power is all Hydro which is a renewal resource. USA loves coal. It is dirty and high pollution. I was involved in 1991 in converting a coal-fired Power Plant in Selkirk, MB to natural gas. It is now closed.
⚠️ *This video took a long time to make* if you would like to buy Paul a coffee to say thanks, link below: ☕
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It's amazing how little people think about the future use compared to ”It's cheaper? Perfect! Just install that one!” or ”Yeah, we can just fix it later.”
It depends on the financial standpoint of a business owner or investor. They may not have enough money right off the bat to pay for the extra ductwork and equipment in more advanced systems. They just want to get the business up and rolling
Dual duct systems were extremely common in the 60s through the 80s in the US. At my university here in Texas, all the original dual duct systems from the 70s are still going, complete with all the ancient mixing boxes, tiny high static hot/cold deck ductwork, pneumatic thermostats, and the enormous custom AHUs literally built into the buildings. Interestingly enough, one of our buildings completed as late as 2008 has a dual duct system. Dave McFarlane has an interesting writeup on old systems called "Retrocommissioning older buildings."
I liked the CAV HVAC System video you did a couple of years ago but this one was, well better explained I must say.
Just a mention that CAV’s are still used in places where the air exchange per hour (ACPH) is required.
I work in a decent-size modern hospital and air-turnover is critical to pass inspections.
It seems so obvious, but I had never even considered air turnover - let alone a hospital. Glad to hear it's a thing, though.
Thanks for the PDF file I hope HVAC pdf file is also available. this channel is awesome
Interesting as always 👍
Thanks for sharing 👍😀
easily explained video, as always. @4:33 the total flow rate is fixed, but to the individual diffuser, with the help of damper, we can decrease the individual flow rate (e.g. to 3 cubic m/s) although the total flow rate (e.g. 20 cubic m/s) will remain constant, right?
Waw ! Amazing 🤩
Very nice sir. time is no issue understanding is important 😊
Thank you Sir
Could you pls make a video to talk about duct sizing using static regain method with some examples? Thank you.
Please make a detailed video about transistors and their uses,types,working and why they are revolutionary invention
I know that there are many videos about transistors but your animation and explanation is best 😁
Transistor video now live: ua-cam.com/video/J4oO7PT_nzQ/v-deo.html
Good job
thanks a lot for these learning materials. Maybe just put radius also on the duct work illustrations since these 90 degree designs creates air losses on the system.
Paul can you please make a load calculation video?
As always videos are great. Have you thought about adding a multizone CAV system to your examples? I've been looking for more info about them, but there's not a lot out there. Seems similar to the dual duct system but the individual zone dampers/actuators are at the AHU with multiple ducts feeding the different zones. Thanks!
Sir please make a video on motor driver..
30 m3/s is a lot of air. Not by any means small ahu can provide that kind of air volume flow. Also, rotating or crossflow heat energy recovery is now day pretty much standard in AHU units. At least here in Finland.
Cross flow covered here in detail: ua-cam.com/video/KCiv8IAUkh8/v-deo.html
Would a VAV control system also require cooling at the AHU as well as reheating for the VAV box terminals? Is there a substantial difference in this way between CAV and VAV? Or is it solely due to the modulation of air volume (and furthermore, heating) for the individual rooms in a VAV system that saves energy?
Unbelievable brooo
Very informative
@3:53 you are saying that temperature changes in different rooms, but @5:51 you are saying all the rooms receive the same temperature. I don't get it. Is it that normally in CAV, you get same temperature in all rooms but by using inefficient terminal heater/cooler you can get varied temperature?
You've misunderstood. 3:53 every room receives the same temperature air, we can change the air temperature but every room will get this.
So I'm curious; if they have to chill the incoming air to a set temperature anyways, then reheat the air at the point of use; why not use a heat pump to simultaneously chill the air coming into the building, and heat air at the point of use?
Crt me if I'm wrong...in this there no separate CAV box like VAV box only the thing is to add on heater or similar to heating unit. So CAV is one type of system which we used early. There is no use of it ..and one more question instead of VAV can we use motorized VFD for the same it can also be control the flow as well by using the thermostat. And why do we need air flow sensor on VAV we were already controlled by thermostat... please clear my doubts ????????
Please do videos on generator working please.... TQ
Do you have video or book about HVAC design in Pharma industry .where some room must be positve pressuer and other is negative ...etc
Please make a video on work of rechargeable battery..
Have you watched our car battery video? That's rechargeable
No I am talking about the AA battery
It's like alkaline battery but rechargeable
Рақмет 2024 🇰🇿
Big brain
Hi, would you mind if you make some more videos about water system in hotel or in the house ?
I am back to bother you :)
Can you do more motor control? i.e. soft starters? Perhaps some steam plant stuff (high pressure steam), hydraulics, and pneumatics? Diesel generators? New processes vs old processes? Things found in institutions like universities and hospitals, and whether or not they differ from commercial and industrial? Have you considered including a bit more calculation in your videos? Or another channel to connect the visuals with the calculations for the math nerds? MORE MORE GIVE ME MOAAAAAAAR
cool
But I think in CAV system we can regulate the flow rate of air to the room if we will put VCD in room branch.
Suppose, you are telling for one room 30m3/min in 13degree is very high, so we can adjust damper and get 20m3/min in 13 degree, and that will be sufficient for room.
Where I am wrong, please, explain me
4:32 That poor guy got his office right next to the server :c
That’s me, I sit in our server room :) it’s like Antarctica in there to keep the servers cold 🥶
Sounds like you need this video ua-cam.com/video/xBxyhxmhigc/v-deo.html
@@EngineeringMindset haha :D But I was referring to the noise.
Now lets see what video you will recommend :D
@@relevantinformation6655 yep, best place in the building. IDK why he thinks that guy is a poor guy.
Bro cold storage wiring diagram pls explain
No mention of TAB? Testing, Adjusting, and Balancing that makes the system actually do what its supposed to and where problems might be discovered. Also, You don't adjust the Volume dampers during commissioning. You do that's during TAB by a certified technician that sets total fan speed as well as each diffuser output. Arguably one of the most important parts of commercial HVAC, by making sure that expensive system is doing what it was designed to due.
Are VAV systems still preferred over CAV during covid-19 because of the lack of air volume exchanges instead of constant air exchanges?
Can you do a video about solar hibrid air conditioners? How do they work? Or is it a scam?
Seen our new video on HOW SOLAR PANELS WORK in detail ua-cam.com/video/Yxt72aDjFgY/v-deo.html
Bro can you please tell me how to convert 12v dc to 12v ac current?
ua-cam.com/video/iIqhAX0I7lI/v-deo.html
hi can you share me z guide book(hvac design) pls.
Columbus Cliffs
Old buildings+a not for profit company= steam reheat. Good times
Can u do a Hybrid Variable Refrigerant Flow
See this video ua-cam.com/video/xwvkojKiLJM/v-deo.html
CAN U PUT ONE VIDEO OF RESISTOR PLSS
Check out NEW resistor video, everything covered! ➡️ ua-cam.com/video/DYcLFHgVCn0/v-deo.html
*When u r not first and have nothing to say now* 😂😂😂😂😂
ya a damper will solve your problem, no need for re heaters and all that
Just saw this and i puked a bit in my mouth.. we have a CAV system with two machines built in our newly built hotel.. one zone for the guest rooms, one zone for the tiny bar, two guest kitchens, a green room, the only meeting room and the lobby.. so a silent meeting room has the same Volume (sound not air) is present in the meeting room as in the lobby.. then in the summer in the lobby doors are open, upper floors without windows that can be opened and the whole thing can't go below 18°c degrees which are realistically 21°c and then the chiller dies...
Not First😒
You are first
@@EngineeringMindset 😁😁
This type of system is normally done with a Rootop unit or a furnace. I have designed over 5000 Electrical & Mechanical projects. I am an electrical & mechanical engineer. If they want temperature control I just install a zone damper system. An HRV is usually installed as well. I have never seen this system in a large building. Normally VAV with mixing box at the air handler. Mostly pneumatic controls and hot water rads. I also built myself 100 apartments as of recent. I was the engineer and contractor and I own the buildings. All 100% Electric. No gas. In Canada. I hate gas. It is dangerous and in Manitoba, our power is all Hydro which is a renewal resource. USA loves coal. It is dirty and high pollution. I was involved in 1991 in converting a coal-fired Power Plant in Selkirk, MB to natural gas. It is now closed.
Good day sir! I am interested in working as an HVAC engineer in Canada. May I ask for your email sir?
Thank you sir