So much of this was over my head but I was able to follow the overall concept. Given the fact I’m not even close to being called an engineer, you really lived up to your channel name. Excellent job of explaining complex issues, in an understandable way, without making me feel condescended to, thank you.
Just enjoyed your video for the first time today on its 4th anniversary. 690,606 views is a testament to how well delivered the material was in your video. As I find myself less and less confident in contractors of late, it is appreciated that you are providing content to empower viewers with knowledge that might have felt out of reach initially. Thanks again and many well wishes for continued success for you and your channel.
Bro I wish I saw this a few years ago when I started as an hvac engineer. You described something that took me months to get the full picture from the lax training at my company.
Yeah this is pretty cool. Im a sheet metal apprentice, specializing in ductwork for commercial jobs. Interesting to see how the ductwork I make is designed and such. Great video!
I’m the same here just helped commission a job and was curious how they came up with air flow rates on the drawing and it’s pretty insane how much goes into it just for us to come along and make they’re job more fun 😂
I got my Ac system installation almost a year ago, it smells very bad and when I turn it on it smells like dump wet bathroom. In order to get it to stop smelling I have to get the temperature down to 24, but then it's too cold😢 does anyone know if they have done for me a cowboy job, as I have spent a lot of money
@@victory6904 24 degree fahrenheit? Or Celsius. Either way you could have someone come potentially clean it, install uv lights or some sort of duct cleaning system. It sounds like it might be mildew caused by not properly insulated duct so it could be sweating and building up water that's smells gross. Could be improper drainage. Hard to diagnose something on the Internet just get a professional to look at it
As someone who has been doin HVAC design for a while, this is very helpful if you’re trying to understand the theory and calculations for the design. But in the real world, no one is going to build ductwork like yours because everyone is cheap and prefers round taps and tee junctions.
This was a fantastically simple overview of the engineering process needed to accurately specify a ducting system. Here in the States among contractors, the most common method for duct sizing in residential is the "friction loss per 100 ft." method wherein we calculate the total equivalent length for the longest runs (both supply and return) and size everything based on getting the appropriate amount of air to these runs and balancing the rest with dampers. Really wish there was an instructional video on this process (or even the equal friction method) in Imperial units out in UA-cam. Thanks for providing such fantastic resources for the industry.
Great video, it's important to also note that's another driving factor for the mass flow rate is the fresh Air supply which is higher than your cooling or heating loads would override your video size
You do all this, provide your quotation and you are too expensive. Then a cowboy contractor comes in (who calls himself an engineer), oversizes the ducts, undersizes the fan, uses wrong grade filters and charges far less. Then you are asked to go and see why the system does not perform, you make a list and the customer prefers not to do anything after all when they see the bill. At the end we are out of pocket for the time spent sizing a proper system, twice, and we end up not getting the job. At the end of the financial year we struggle to pay our subscription to the Engineering Council.
So offer them a different business model. Give them a simple 1 page of what seems wrong and if they want the full answer then they need to pay for a review and offer to deduct this from the final quote if they choose to use you. Estimate the financial and energy savings from the improvement as well as how it will improve their work/living conditions.
The Engineering Mindset You said the magic word, energy saving. I had customers prefering to go with normal AC motor fans because they were cheaper to buy than EC motor fans that would pay for themselves in a couple of years and start providing true money saving. Anyway, it is a big discussion this one. Great video by the way, as always.
this business model idea is what we do in the cloud computing world. an architect gives them a basic idea of the price, and work required based on a basic conversation with them, tehn an engineer gives them the actual plan, and hours breakdown, based on a deep dive discovery. a lot of times, we are on or under cost, but that comes with experience. you have to do the calculations to 'pay your dues' as it were until you reach architect level, where you can spitball an estimate, and be pretty close.
Great video this, can you also do a video on "calculating the cooling and heating loads using psychrometric charts" for HVAC systems? Really appreciate it if you can
Amazing video, thank you. I noticed in the video (14.39) you are inputting the data into the interpellation website. that you input in Q11 value 0.14. Should it had been 0.15? (LOL) Its just me and no big deal. It kept me on my toes...so very helpful on your part. Love the videos.....THANK YOU
Sohrab: Ques 4:- Coefficient of pressure values of fittings like Reducer=0.25 Elbow=0.27 It will varies or fixed according to CFM Ques 1:- During calculating static pressure only critical path will be taken or not ? Ques 3:- In formula (F×L)/100 F= friction factor or friction head loss Ques 2:- we will calculate all the VCD OR only critical path?
I have two comments : First: pressure loss for Tee G-I (bend) is less than G-J (straight) How ? Second: we need link for the duct pressure loss chart thank you so much Great video about Duct Design
This is a great educational video, but I have been doing HVAC design for commercial building for few years and usually you just use 0.1 in wc (water column) of static loss to size supply air ducts. For return air ducts, it’s 0.08 in wc. If you do all this detailed analysis, you will never be able to complete large projects on time or schedule and your firm will loose clients.
I have a question. While you design hvac systems for your clients how much of the hand calculations do you have to do. or do you just work with the revit software?.
Nice and clear video, well done. Do you have any videos on how to calculate proper condenser and evaporater size/capacity in relation to compressor size/capacity on custom AC units ? If not please consider making one. Thanks
Loved the video - can you make one with Imperial measurements for your slower US brethren? :) You can say - oh just use feet vs... However if the video was done all the way through with measurements we'd likely use, it would be easier to follow.
Plz make a video of external static pressure calculation explain in detail (straight, elbow, offset,shoe or collar piece ,round to Square or rectangular duct ,all type of fittings like VCD ,FFD ,MVCD,MFD etc...)
Hi, Amazing video, really has helped me complete an assignment that I had no information on how to complete. However I'm still going to fail because you didn't calculate grilles. Also you stated that you would include the fitting tables you used in the video in the description, but it's not there and I have spend the last two hours looking for a god for saken fitting tables to no avail.
@@EngineeringMindset Aha! I see, in that case, thank you. Your videos are just so well put together and beautifully explained, you honestly really helped me out. Thank you for replying.
Hi At 15:42 you calculated the C0 from the table and interbolation, and you forgot to calculate the P loss in the bend direction using the formula (P=C0*density*velocity^2/2) ,you have put it into the table directly . Plz notice that and if i'm Wrong tell us the Right plz.
Fitting loss in G-I direction should not be 0.36. I guess, 0.36 is the Fitting Coefficient. So, the fitting loss in G-I direction should be 2.65. Please correct me if I'm wrong. Thank you.
Great video, I just have one question. When determining the mass flow rate, in the image it says to use delta T in terms of Kelvin but I believe you used your 8 degrees Celsius to get the mass flow rate for each room? Should we convert that into Kelvin?
I don't know a darn thing about HVAC but I do know maths. Towards the end, you discuss losses and using baffles to compensate. I don't see anything about the origination fan, it's CFM, and any filters throughout this system. I would like to build out my own system originating from a window and a plenum box, where a blower is first, then a MERV or HEPA filter, followed with 4 UVC lamps. This system will only supply two rooms with a "junction" or collector as I call it, in-between both rooms (hallway) that is again supplied with a MERV or HEPA filter and UVC lamps out to the second room. Second room is much larger than the first originating room. Two exhausts, one inside origination window above and other through window of second room.
This is insanity...I mean...for large buildings, this is absolutely essential. But for small offices and small homes, surely you can simply this and still get results that are perfectly sufficient? Any negative effects in such a small and simple installation couldn't possibly be that significant with a more simplified method of ductwork design. Unless the design work was 100% guess work, I just can't imagine there isn't a simpler way to do this on the small scale. Example: I have a one story home with a fully submerged basement. One room has a significantly larger load than the rest of the home (TV, computer, UPS, File server, mini fridge, and two people that are in there frequently)...there must be a relatively simple way of figuring out how to move enough of this room's air to the central unit fast enough, in order to remove the heat at a rate greater than that which it is being built up with fewer calculations.
In calculating the pressure loss in the Tee Fitting, why do you only apply the dynamic loss formula in the straight direction and not in the bend too? For the bend you've only used the co-efficient of 0.3645 (15:45) and not used this in the dynamic loss equation, like you did after getting the co-efficient of 0.143 in the straight section (14:45).
Ok this is what I want to get into. Sounds really interesting. I currently have this oversized fan in my house. The duct looks waay too small and the noise is the biggest problem. I was thinking to increase the size of the duct to lower the noise but will try first to use these calculations to see if it would make any losses in terms of cooling. Do you (or anybody here in comment section) have any advices on how to lower the noise without loosing too much on cooling? Thank you in advance.
⚠️ *Found this video super useful?* Buy Paul a coffee to say thanks: ☕
PayPal: www.paypal.me/TheEngineerinMindset
Done ;-)
comment the photo of the Duct Pressure Loss Chart Please :(
@@JudgeFredd so 33
Could you do one about fabric ductwork?
So much of this was over my head but I was able to follow the overall concept. Given the fact I’m not even close to being called an engineer, you really lived up to your channel name. Excellent job of explaining complex issues, in an understandable way, without making me feel condescended to, thank you.
Yes I suffered many a nose bleed during this video
Just enjoyed your video for the first time today on its 4th anniversary. 690,606 views is a testament to how well delivered the material was in your video. As I find myself less and less confident in contractors of late, it is appreciated that you are providing content to empower viewers with knowledge that might have felt out of reach initially. Thanks again and many well wishes for continued success for you and your channel.
Bro I wish I saw this a few years ago when I started as an hvac engineer. You described something that took me months to get the full picture from the lax training at my company.
Yeah this is pretty cool. Im a sheet metal apprentice, specializing in ductwork for commercial jobs. Interesting to see how the ductwork I make is designed and such. Great video!
I’m the same here just helped commission a job and was curious how they came up with air flow rates on the drawing and it’s pretty insane how much goes into it just for us to come along and make they’re job more fun 😂
As an engineer, this has help me a lot. Thank you so much for teaching and making useful video like this. Dont stop!
I got my Ac system installation almost a year ago, it smells very bad and when I turn it on it smells like dump wet bathroom. In order to get it to stop smelling I have to get the temperature down to 24, but then it's too cold😢 does anyone know if they have done for me a cowboy job, as I have spent a lot of money
@@victory6904 24 degree fahrenheit? Or Celsius. Either way you could have someone come potentially clean it, install uv lights or some sort of duct cleaning system. It sounds like it might be mildew caused by not properly insulated duct so it could be sweating and building up water that's smells gross. Could be improper drainage. Hard to diagnose something on the Internet just get a professional to look at it
Another good thing to mind when sizing ducts is the aspect ratio. Ashrae allows us to size on 1:4 basis while CIBSE mentions to size at 1:3.
*ASHRAE
As someone who has been doin HVAC design for a while, this is very helpful if you’re trying to understand the theory and calculations for the design. But in the real world, no one is going to build ductwork like yours because everyone is cheap and prefers round taps and tee junctions.
Are you interested in designing HVAC for a house I’m building? We’re planning on installing so I can’t find anyone who will just design it
This was a fantastically simple overview of the engineering process needed to accurately specify a ducting system.
Here in the States among contractors, the most common method for duct sizing in residential is the "friction loss per 100 ft." method wherein we calculate the total equivalent length for the longest runs (both supply and return) and size everything based on getting the appropriate amount of air to these runs and balancing the rest with dampers.
Really wish there was an instructional video on this process (or even the equal friction method) in Imperial units out in UA-cam.
Thanks for providing such fantastic resources for the industry.
Look up the "ACGIH Industrial Ventilation" manual. You can download the 23rd edition for free on google. It has step by step examples.
Just want to say, this video fixed my exam project for HVAC
what is your project?
watch How *AIR HANDLING UNITS* work here: ua-cam.com/video/KCiv8IAUkh8/v-deo.html
Great video, it's important to also note that's another driving factor for the mass flow rate is the fresh Air supply which is higher than your cooling or heating loads would override your video size
Agreed. This is where hydronics are strong - separating the ventilation needs from the load needs.
Great video! Very similar to how I learned in Applied Fluid Mechanics class!
great video man as always
and congrats for 100k subs.
You do all this, provide your quotation and you are too expensive. Then a cowboy contractor comes in (who calls himself an engineer), oversizes the ducts, undersizes the fan, uses wrong grade filters and charges far less.
Then you are asked to go and see why the system does not perform, you make a list and the customer prefers not to do anything after all when they see the bill.
At the end we are out of pocket for the time spent sizing a proper system, twice, and we end up not getting the job. At the end of the financial year we struggle to pay our subscription to the Engineering Council.
So offer them a different business model. Give them a simple 1 page of what seems wrong and if they want the full answer then they need to pay for a review and offer to deduct this from the final quote if they choose to use you. Estimate the financial and energy savings from the improvement as well as how it will improve their work/living conditions.
The Engineering Mindset You said the magic word, energy saving.
I had customers prefering to go with normal AC motor fans because they were cheaper to buy than EC motor fans that would pay for themselves in a couple of years and start providing true money saving. Anyway, it is a big discussion this one.
Great video by the way, as always.
this business model idea is what we do in the cloud computing world. an architect gives them a basic idea of the price, and work required based on a basic conversation with them, tehn an engineer gives them the actual plan, and hours breakdown, based on a deep dive discovery. a lot of times, we are on or under cost, but that comes with experience. you have to do the calculations to 'pay your dues' as it were until you reach architect level, where you can spitball an estimate, and be pretty close.
Manolis Theofilos I do the calculations after I get a deposit.
We usually have a contract drawn up before we begin work. Either fee or hourly based.
Great video this, can you also do a video on "calculating the cooling and heating loads using psychrometric charts" for HVAC systems? Really appreciate it if you can
refer to ashrae brother, so much easy to follow when you have ashre guidelines
Wow that’s like our HVAC course lectures❤
Amazing video, thank you. I noticed in the video (14.39) you are inputting the data into the interpellation website. that you input in Q11 value 0.14. Should it had been 0.15? (LOL) Its just me and no big deal. It kept me on my toes...so very helpful on your part. Love the videos.....THANK YOU
Great video !Thank you so much , greatting from Việt Nam!
Very informative. I want to try doing HVAC at my home by myself. Thanks for the video.
Sohrab:
Ques 4:-
Coefficient of pressure values of fittings like
Reducer=0.25
Elbow=0.27
It will varies or fixed according to CFM
Ques 1:-
During calculating static pressure only critical path will be taken or not ?
Ques 3:-
In formula
(F×L)/100
F= friction factor or friction head loss
Ques 2:-
we will calculate all the VCD OR only critical path?
Thank you, for giving great and more easily understandable video
Just another very good simple method. Thank you
Love from India ❤
So much help in my project rn. Thanks bro.
Very informatory. I liked this a lot.
i actually use simscale what a peace of software
I have two comments :
First:
pressure loss for Tee G-I (bend) is less than G-J (straight) How ?
Second:
we need link for the duct pressure loss chart
thank you so much
Great video about Duct Design
0:47
1:15
1:46
2:55
6:13
8:52
9:55
10:30
12:44
12:55
13:32
14:17
15:06
15:55
16:43
Helped me in my project. Great work!!
thank you for this video!!! it's very helpful!
Excellent One. Thank you for your effort.
Helpful and to the point explanation , thumbs up!
Intro sounds chiller 😍
great video..really helpful.thanks engineeringmindset.
This is a great educational video, but I have been doing HVAC design for commercial building for few years and usually you just use 0.1 in wc (water column) of static loss to size supply air ducts. For return air ducts, it’s 0.08 in wc.
If you do all this detailed analysis, you will never be able to complete large projects on time or schedule and your firm will loose clients.
I have a question. While you design hvac systems for your clients how much of the hand calculations do you have to do. or do you just work with the revit software?.
very nice sir, HVAC&R ENGINEER from pakistan
Glad you enjoyed it
great video, how about exhaust ventilation systems which is the opposite?
Hi, nice video. please note that there is a little mistake in calculation.
1.026 * 8 = 8.208 kj/kg but it is calculated 8.028 kj/kg.
Nice video! Grill style and size also effect static pressure but that's probably part of a different video
Any plans of making a tutorial on how to read complex ductwork drawings?
Amazing videos seriously.
Thank you so much for making this video. Very helpful.
Mantaps Good! Love This channel!
THANK YOU AND KEEP THE GOOD WORK.
Nice and clear video, well done.
Do you have any videos on how to calculate proper condenser and evaporater size/capacity in relation to compressor size/capacity on custom AC units ?
If not please consider making one.
Thanks
You’re amazing fam.
great video which helps me a lot.
Air volume in HVAC is by sensible heat, without sensible heat. Duct is only GI gage 22 from sizing.
Great video!!!
Loved the video - can you make one with Imperial measurements for your slower US brethren? :) You can say - oh just use feet vs... However if the video was done all the way through with measurements we'd likely use, it would be easier to follow.
Thank you for good detail’s of informations going keeping
Great video..... Thank you so much
New subscriber here, great video
Off course we enjoy it .
Sure it helps us .
Thank you, genius .
Great video.
Thankyou so much for this sir
That was great, thank you!
You mention about heating and cooling load calculation on 1:15..have you already done the seperate video?
Awesome explanation. Really useful!!
Do you have more videos on ventilation duck sizing as mentioned in this videos?
Yes have a look at out channel ua-cam.com/channels/k0fGHsCEzGig-rSzkfCjMw.htmlvideos
Great video. Really well explained!
This is so freakin helpful
Plz make a video of external static pressure calculation explain in detail (straight, elbow, offset,shoe or collar piece ,round to Square or rectangular duct ,all type of fittings like VCD ,FFD ,MVCD,MFD etc...)
Great video!! Thanks for sharing!!
One question: What about split systems? How can I size the ductwork? is it necessary?
Hi,
Amazing video, really has helped me complete an assignment that I had no information on how to complete. However I'm still going to fail because you didn't calculate grilles. Also you stated that you would include the fitting tables you used in the video in the description, but it's not there and I have spend the last two hours looking for a god for saken fitting tables to no avail.
😕? I left 3 links for the exact books you need with all the information in, in the video description. You're welcome.
@@EngineeringMindset Aha! I see, in that case, thank you. Your videos are just so well put together and beautifully explained, you honestly really helped me out. Thank you for replying.
Thanks! You are awesome. 👍
Very helpful
I love it, thanks!!
Great video this can you make video on DX UNIT
Thanks for this video
U so much good and talent never giveup go ahead 😍😍🤗🤗 but this video so much fast ...
thank so much for video,its very helpful, de argentina muchas gracias
Hi
At 15:42 you calculated the C0 from the table and interbolation, and you forgot to calculate the P loss in the bend direction using the formula (P=C0*density*velocity^2/2)
,you have put it into the table directly
.
Plz notice that and if i'm Wrong tell us the Right plz.
Hmmm i notice that when u do consistency of units it come out like Kg/m.s2. idk maybe im wrong?
ايش الصحيح ؟
Fitting loss in G-I direction should not be 0.36. I guess, 0.36 is the Fitting Coefficient. So, the fitting loss in G-I direction should be 2.65. Please correct me if I'm wrong. Thank you.
Good work .
Thanks
Do you have a video that when you have a rectangular ducting instead of round ducting?
Amazing video btw. thanks!
Great video, I just have one question. When determining the mass flow rate, in the image it says to use delta T in terms of Kelvin but I believe you used your 8 degrees Celsius to get the mass flow rate for each room? Should we convert that into Kelvin?
great job
Mulțumim!
Thank you!
Thank You
Really good
I have never seen this method of calculating duct. It looks like a quick and simple method instead of calculating the Liters per second or CFM.
Great video this
excellent video,,,
I don't know a darn thing about HVAC but I do know maths. Towards the end, you discuss losses and using baffles to compensate. I don't see anything about the origination fan, it's CFM, and any filters throughout this system.
I would like to build out my own system originating from a window and a plenum box, where a blower is first, then a MERV or HEPA filter, followed with 4 UVC lamps. This system will only supply two rooms with a "junction" or collector as I call it, in-between both rooms (hallway) that is again supplied with a MERV or HEPA filter and UVC lamps out to the second room. Second room is much larger than the first originating room. Two exhausts, one inside origination window above and other through window of second room.
Can you do a video on the Velocity Reduction Method?
Thanks for this video....
dude, that's very helpful .. thank you so much :) !
Can you plz make a video of flat oval or elliptical duct sizing ,it is helpful for us
Hey bro, got any idea of how to find the area of rectangular one?
god damn i love your content, thanks a lot
Very good
i love this video, thanks
This is insanity...I mean...for large buildings, this is absolutely essential. But for small offices and small homes, surely you can simply this and still get results that are perfectly sufficient? Any negative effects in such a small and simple installation couldn't possibly be that significant with a more simplified method of ductwork design. Unless the design work was 100% guess work, I just can't imagine there isn't a simpler way to do this on the small scale.
Example: I have a one story home with a fully submerged basement. One room has a significantly larger load than the rest of the home (TV, computer, UPS, File server, mini fridge, and two people that are in there frequently)...there must be a relatively simple way of figuring out how to move enough of this room's air to the central unit fast enough, in order to remove the heat at a rate greater than that which it is being built up with fewer calculations.
Can you do another difficult example with grille/coil etc.?
Sent you a coffee Paul :)
Thanks, Tony.
Can you please upload full hvac system
These videos are obsolete and fantastic explanations for refreshers on these in little things
In calculating the pressure loss in the Tee Fitting, why do you only apply the dynamic loss formula in the straight direction and not in the bend too? For the bend you've only used the co-efficient of 0.3645 (15:45) and not used this in the dynamic loss equation, like you did after getting the co-efficient of 0.143 in the straight section (14:45).
was that a mistake ? or its how it done ?
I noticed that as well. It looks like an honest mistake.
Ok this is what I want to get into. Sounds really interesting. I currently have this oversized fan in my house. The duct looks waay too small and the noise is the biggest problem. I was thinking to increase the size of the duct to lower the noise but will try first to use these calculations to see if it would make any losses in terms of cooling. Do you (or anybody here in comment section) have any advices on how to lower the noise without loosing too much on cooling?
Thank you in advance.