ducts drawing problem

[ke_ch]

how to draw the offset of a duct? if my duct goes to one way and then has to offset 90 degree. what is the radius should the round connection be?

 

Did anybody have any example?

[mdbdesign]

2 x dia of duct???

[ke_ch]

2 x dia of duct???

 

 

what about if I want to connect a branch duct to a main duct which is bigger than the branch duct

[mdbdesign]

Use reduction or something like on picture

[chelsea1307]

no need to reduce your main to branch off with something smaller.

[CADMASTER1128]

I don't know if this will help, but this is how I draw my HVAC ducts.

 

Drawing organically drawn by StykFace.

[mdbdesign]

...or something like this:

(just learn how to add picture:-))) )

[chelsea1307]

learn something new everyday, ive never seen branch off a reducer

[tzframpton]

learn something new everyday, ive never seen branch off a reducer

This is very common in the HVAC industry. Granted its a custom fitting that usually costs more which can drive up bid price, but for very widely used sizes, this is definitely common.

[tzframpton]

what about if I want to connect a branch duct to a main duct which is bigger than the branch duct

Are you using MEP or plain AutoCAD?

[chelsea1307]

Granted its a custom fitting that usually costs more which can drive up bid price, .

could be why i havent seen it, we do a lot of schools and they have to take the lowest bid, so we avoid custom things that can be done with standard parts

[mdbdesign]

Sometimes it is just impossible to avoided

[tzframpton]

Sometimes it is just impossible to avoided

Not only that, but a 12x10x8 fitting is a standard catalog fitting which doesn't fall under the "custom" fitting part of a duct manufacturer. But a 16x8x6 would be because its FAR less used than the other, so a duct manuf. would have plenty of stock of the typical ones used.

[Tankman]

Years ago I was a layout man for industrial duct work.

 

I was surprised when we fab'd duct to move cotton around a processing plant.

Cotton would wear out the duct very fast, we reinforced the duct with heavy steel which the cotton would polish the inside of the duct, and soon, blow out the fittings.