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hamidpia
19-08-2007, 08:53 AM
I need help in calculation of duct size
For equal friction method using friction loss of 0.1in/100ft for supply and 0.05/100 ft for return, do we need to calculate friction loss for the actual length of duct after taking in to consideration loss added by fittings. Where do we get information about loss added by fitting. till now I am simply aligning 0.1 in against cfm and finding the duct size in the window disregarding duct length.
Best regards
Hamidpia

vijay_study
19-08-2007, 02:10 PM
Hi,

Based on equal friction method, you are following correct procedure.

With reference to length of ducts, it needs to be measured so that static pressure of blowers can be calculated.

Pressure loss across duct fittings can be obtain from chapter on duct fittings from ASHRAE handbook.

Regards

lam vy
25-08-2007, 03:45 AM
This is a small software (vietnamese) for Duct Size Calculations.
You can try using it . Simply, you click start button-enter unit for air volume and.......
If you have any better software , could you give it to me ?
Thanks for using my soft and pls give me some comments.
Bye !
I forget to give user and password to you
here
u : vee
p: tienvy

uname2000
12-08-2008, 12:53 AM
This is a small software (vietnamese) for Duct Size Calculations.
You can try using it . Simply, you click start button-enter unit for air volume and.......
If you have any better software , could you give it to me ?
Thanks for using my soft and pls give me some comments.
Bye !
I forget to give user and password to you
here
u : vee
p: tienvy
lam vy,

I am Danh new to here. Would you give me more information of how to calculation the duct size please? Send me email at Danny.huu.tran@gmail.com.

Thanks

Brian_UK
26-09-2008, 11:01 PM
I need help in calculation of duct size
For equal friction method using friction loss of 0.1in/100ft for supply and 0.05/100 ft for return, do we need to calculate friction loss for the actual length of duct after taking in to consideration loss added by fittings. Where do we get information about loss added by fitting. till now I am simply aligning 0.1 in against cfm and finding the duct size in the window disregarding duct length.
Best regards
D.Vinothkumar
HVACPlease explain why you have repeated the first post ?:(

vee
09-03-2010, 12:45 PM
there's no english software for calculating the duct size???

Josip
09-03-2010, 02:31 PM
Hi, vee :)


there's no english software for calculating the duct size???

for sure there it is ... even searching RE forums is possible to find many links or formulas how to calculate ducts...

for some reason (or maybe by default) this way is easier ... otherwise our poster/s must spent some time for searching

... and maybe learn something what is not so popular nowadays, no time ;) .... only instant answers ...

Best regards, Josip :)

dougheret0
10-03-2010, 03:51 PM
there's no english software for calculating the duct size???

An article in the May 2009 ASHRAE journal describes an Excel spreadsheet that sizes ducts by the equal friction method, and computes fan external static. I would attach the article, but it's too big. You may be able to access it at the ASHRAE journal web site. It is possible also that you can still download the spreadsheet from the web site. I have a copy and could attach it, but this forum does not support .xls attachments.:(

charlie n
10-03-2010, 11:08 PM
An article in the May 2009 ASHRAE journal describes an Excel spreadsheet that sizes ducts by the equal friction method, and computes fan external static. I would attach the article, but it's too big. You may be able to access it at the ASHRAE journal web site. It is possible also that you can still download the spreadsheet from the web site. I have a copy and could attach it, but this forum does not support .xls attachments.:(

Hi Doug,
PLease send the spreadsheet to me at subcooleng@gmail.com

GBRD
15-04-2010, 05:18 AM
Hi Doug, Pl send me also this spreassheet on gaurav_s55@yahoo.co.in

regards

GBRD

fredydxb
19-04-2010, 07:22 AM
Hello Doug,

It is great to be able to share our knowledge and experience on this nice forum. I appreciate if you can forward that excel sheet of duct sizing on my email herebelow:
hamatif@live.com

Thanks a lot.
FADI

pignatelli
07-06-2010, 11:58 PM
I Doug can you can forward that excel sheet of duct sizing on my email herebelow:

pignatelli.eng@gmail.com

Thanks

vee
13-06-2010, 07:54 AM
An article in the May 2009 ASHRAE journal describes an Excel spreadsheet that sizes ducts by the equal friction method, and computes fan external static. I would attach the article, but it's too big. You may be able to access it at the ASHRAE journal web site. It is possible also that you can still download the spreadsheet from the web site. I have a copy and could attach it, but this forum does not support .xls attachments.:(
hi doug plz can u forward me execel sheet for duct sizing i wil be very thankful to u mohdmohsin_j32@yahoo.co.in

vee
13-06-2010, 08:00 AM
This is a small software (vietnamese) for Duct Size Calculations.
You can try using it . Simply, you click start button-enter unit for air volume and.......
If you have any better software , could you give it to me ?
Thanks for using my soft and pls give me some comments.
Bye !
I forget to give user and password to you
here
u : vee
p: tienvy
hi plz can u send the software for duct sizing in english to mohdmohsin_j32@yahoo.co.in

pramothmech
15-06-2010, 08:54 AM
hi friends here i attached duct calculator....:)

pramothmech
15-06-2010, 09:00 AM
hi friends here i attached duct calculator....:)



4shared.com/file/FXCjAReY/ductsizer.html use this link to download

B G Scott
15-06-2010, 09:56 AM
hi doug plz can u forward me execel sheet for duct sizing i wil be very thankful to u mohdmohsin_j32@yahoo.co.in
All you will ever need for duct size calcs and fan engineering go to the link below
www.flaktwoods.com/34bd869d-e1da-4f17-9209-8bb33b2ffa8a

dougheret0
21-06-2010, 01:56 PM
At my web site www.nettally.com/doughert (http://www.nettally.com/doughert) you will find an excel spread sheet that calculates duct size, air flow velocity, and external static pressure for a duct system. You can input the friction loss/100 ft that you want to use, the air flow rate, the duct height if rectangular, and the length of each leg. If the duct is round, you just enter 0 for duct height, and the program computes round duct diameter. Instructions for running the macros are on sheet 1.

This spread sheet was featured in the ASHRAE Journal in May, 2009.

You may contact me if you have questions.