Fire Damper / Smoke Damper / Fire + Smoke Damper 2

[walz]

I need clear differentiation between the functions of Fire Damper, Smoke Damper and Fire and Smoke dampers.

What factors decide the use of each of these three Dampers.
Thanks in advance.

 

[berkshire]

From Mestecks fire smoke damper installation guide :
Dynamically rated fire/smoke and fire dampers are intended to restrict the passage of flame. The dynamically rated fire/smoke dampers are
also intended to restrict the passage of smoke. When the damper is intended to be used as a fire rated damper, the standard installation requires
that the damper is positioned so that the closed plane of the blades is within the fire rated masonry/concrete or metal or wood framed gypsum
wallboard barrier. When the damper is to be used as a leakage rated damper only, the damper is to be installed within 24" of the smoke barrier
and upstream of any duct outlets.

Does this give you what you want?
B.E.

You are judged not by what you know, but by what you can do.

 

[walz]

the main problem in understanding these is .

If damper itself is rated, should it be installed inside a rated duct or non-rated.

or it should not be installed inside the duct, it has to be mounted on structure (fire rated wall etc) with ducts on either side of it.??

 

[sprinkler1000]

The type of damper depends if the duct penetration is through a fire wall, a fire barrier, or a smoke barrier.

 

[berkshire]

Waltz,
If the damper is mounted in a fire wall, the ducts come to the fire damper with S joints on either side, so that in the event of a fire the duct can fall without pulling the damper out of the wall, therebye preserving the integrity of the barrier. So yes the damper is mounted in structure with ducts on either side.
So based on this there is not much difference between a smoke & fire damper.
If the barrier is for smoke only then you are only concerned with keeping smoke out of the area the barrier/damper is protecting. Having the damper away from the wall makes it easier to reset if for any reason it does trip, it is also customary to put an access door in the duct for this purpose.

B.E.

You are judged not by what you know, but by what you can do.

 

[ChasBean1]

Ok – good responses by those before, but harking back to your OP:

Fire dampers have a fusible link that melts and allows the damper to slam shut if the device reaches a certain temperature.

Smoke dampers have an automated function that relies on an actuator driving the damper closed if the duct smoke (within 5’ of the damper) is alarmed.

A combo fire/smoke damper (FSD) has both: a fusible link system that operates at a high temperature plus an actuated assembly based on the duct smoke.

New buildings have a ridiculous amount of FSDs; the FSDs are required all over the place by 8th Edition (US) code. The FSDs produce ten-fold the performance problems than they solve; the code creators might be related to the folks that profit from manufacture of these devices.

 

[berkshire]

ChasBean1 (Mechanical)
I missed that little point about smoke dampers having a mechanical operating arm. Most of the stuff I have used just had the fusible links.
B.E.

You are judged not by what you know, but by what you can do.

 

[NegativeZero]

All the smoke dampers I used were in rooms using FM200 systems. Smoke dampers need to be hooked up to a smoke head or a relay from the fire panel.

fire dampers are rated, smoke dampers alone may not be fire rated for fire walls unless specified and have low or no leakage. Fire and Smoke dampers are fire rated and use a electric heat detector to close on temp rise and can be reset and close on power failure.