Duct sizing questions???

[santi_obejero]

hi there i have few questions here so i hope u could answer..:confused:

is it necessary to use an elbow for distribution of air for duct systems. if yes how can i compute for the correct radius of the elbow...

another question: Is the size of the diffuser different from the size of the pipe where the air will flow...

last question: how can i convert a rectangular duct to a square duct.. Tnx...


Cheers...:D

[nike123]

hi there i have few questions here so i hope u could answer..:confused:

is it necessary to use an elbow for distribution of air for duct systems. if yes how can i compute for the correct radius of the elbow...

another question: Is the size of the diffuser different from the size of the pipe where the air will flow...

last question: how can i convert a rectangular duct to a square duct.. Tnx...


Cheers...:D


Duct work Pressure drop: 60% to 80% of high temperature process duct work pressure drop (http://en.wikipedia.org/wiki/Pressure_drop) occurs in the process equipment, baghouses, mills & cyclones. However since motor 1 (one) horsepower cost roughly $1000/year (US$), duct efficiency is important. Minimizing duct pressure drop is important. most ductwork, non-equipment pressure drop occurs at transitions and changes of directions (elbows). The bests way to minimize duct pressure drop ($) is to use elbows with a elbow radius to duct radius exceeding 1.5. (For a 15 foot duct, the elbow radius would therefore equal, or exceed 22.5 ft.)

http://en.wikipedia.org/wiki/Process_Duct_Work
http://books.google.hr/books?id=G47biva6gtwC&pg=PT674&lpg=PT674&dq=duct+elbow+radius&source=bl&ots=vL6PBV-8lc&sig=hhPIN_Vu4OhPiGXtL-a81Mhk6Ms&hl=hr&ei=070xS_mwDY-h_Abgur3_CA&sa=X&oi=book_result&ct=result&resnum=3&ved=0CBgQ6AEwAjgU#v=onepage&q=duct%20elbow%20radius&f=false

[Brian_UK]

last question: how can i convert a rectangular duct to a square duct.. Tnx...


Cheers...:DThis question tells me that you should get in touch with a ducting contractor/supplier straight away to resolve your problems.

[eggs]

hi there i have few questions here so i hope u could answer..:confused:

is it necessary to use an elbow for distribution of air for duct systems. if yes how can i compute for the correct radius of the elbow...

another question: Is the size of the diffuser different from the size of the pipe where the air will flow...

last question: how can i convert a rectangular duct to a square duct.. Tnx...


Cheers...:D

1) Bend radius is usually 1.5 times duct diameter.

2) Depends what velocity you want the air to exit at.

3)Calculate the perimeter length of the rectangular duct then square root it

Eggs

[santi_obejero]

tnx a lot to those who have replied,,...

cheers..

happy holidays