Duct and Pipe fittings loss 3

[xpsboy]

Anybody can guide me where can I find the equivalent fitting loss for duct and pipe using ASHRAE handbook? I'm browsing my online access of ASHRAE handbook but can't find the tables for equivalent lenght.

Also, when we do the total static pressure head I use % for getting the fitting pressure loss, but if I need to check the duct or pipe system for any pressure head problem its better to ge the value of fittings instead of %. I'm planning to get the actual fittings pressure loss by using the equivalent lenght - or anybody using Smacna for getting the fittitng loss for duct? Which is more safe to use too for getting fittings pressure loss - ashrae or smacna?

 

[MechEngNCPE]

I still use ASHRAE 1993 Fundamentals - it has a great fitting loss section. SMACNA works too. Here's a spreadsheet if its possible to upload..

 

[xpsboy]

Mechengnpce,
I'm on ASHRAE fundamentals chapter 21 duct design but can't find the duct fitting equivalent lenght. Also I'm not familiar using the coefficient for duct fittings, i think i need to use smacna if i will look using the coefficient when finding the duct fittings loss?

 

[MechEngNCPE]

Here is the spreadsheet I use, just punch in the size of the duct and check the appropriate fitting/transition. I use it on all jobs, real quick and easy.

 

[MechEngNCPE]

To find individual pressure losses in inches water multiply the fitting coefficient "C" by the velocity pressure at that fitting.

C*(density of air)(V/1097)^2=fitting total pressure loss

V in feet/min

 

[xpsboy]

Thanks. Where can i found the "C" value using ASHRAE handbook?