load thes coefficient

[Ing Italy]

Hello everyone and good Saturday!
it is for several days that I have been trying to find in the internet data related to load loss coefficients of horizontal and vertical bar rectangular section air vents; I know that probably the solution would come from the book of idelchik but I can't have it since we were in the university library of my city.
I found so much material on the internet but nothing I really would need, you in the past searched and found something like that? .
if you have something you had found in the past I would be very grateful if you could direct me to the site or similar things, thank you and greet:smile:

 

[paulpaul]

test see if this is helpful (at the bottom of the table you have the grills).
http://www.engineeringtoolbox.com/minor-loss-air-ducts-fittings-d_208.html

 

[Ing Italy]

hi, thanks for the link!.coefficient of that kind I had found them but there are some problems:
-the types of grill-free are not specified: the grid in question in my case has a certain height and width cannot be considered simply flat
- my area factor is 0.9 and in the attached link you get to 0.7: possibly I would prefer a coefficient just for this area factor

It's like this.
http://www.google.it/imgres?q=grigl...dsp=23&ved=1t:429,r:21,s:0,i:114&tx=119&ty=65excuse me for the long link but the link to images are always so

 

[paulpaul]

This is pdc coefficients for generic grills used in the ventilation industry, so extremely similar to those that you linked.
I usually use these coefficients in the sizing of the ventilation systems and air replacement of the container for gas compression plants, which are usually equipped with grids of this type both in the input and out.
so in my opinion you can also use them in your case :wink:

interpolate to search for the values that you lack: not linearly, however! tracks the graph with excel and uses the function "fashion line" interpolando con una curve di tipo y = cx^n, con y il coefficiente di pdc e x il relation d'area.

Bye!

 

[Ing Italy]

thanks for the answer... also through other correlations have come to similar results to those you reported.ciao!