Fire Collar Obstruction

[Belinda.Gonzalez@eve]

Hello there!

Could anyone tell me what is the unobstructed distance between a fire collar and another element? Planning to install a PIV unit, running a PVC pipe straight from the rear inlet to a fire-rated wall. I need to install a fire collar behind the unit, but I was wondering what's the separation I have to leave between the PIV and the collar so that the collar won't be affected in performance? Or can the PIV unit be located just after the fire collar? I would like to avoid separating the unit from the wall as much as possible.

I have asked different manufactures but no one has been able to tell me.

I hope this makes sense.

Thanks in advance.

 

[^woody^]

You'll need to take the advice of the PIV manufacturer, not the collar manufacturer.

The collar is designed to activate from a fire within the room and will perform no matter how close the unit is to it. But potentially, a fire within the PIV unit could send heat and hot smoke through the pipe internally before the collar starts to activate - whether that's an issue depends on where the pipe is leading to.

 

[Belinda.Gonzalez@eve]

You'll need to take the advice of the PIV manufacturer, not the collar manufacturer.

The collar is designed to activate from a fire within the room and will perform no matter how close the unit is to it. But potentially, a fire within the PIV unit could send heat and hot smoke through the pipe internally before the collar starts to activate - whether that's an issue depends on where the pipe is leading to.

PIV manufacturer has sent me to the collar manufacturer. I seem to be running in circles.

Your answer is actually very helpful. I thought if a fire occurred within the PIV unit, the PVC pipe would melt from the inside anyway and activate the collar immediately.

The pipe leads to a communal area, so the fire-stopping must happen as soon as possible to not compromise the compartmentation.

 

[^woody^]

Intumescent material only activates at certain temperatures, so you don't really want heat, hot smoke or even cold smoke to go through the pipe before the collar activates to close the gap.

Potentially, heat and smoke could go through the pipe internally before the pipe melts and the external collar activates. It may be that the closeness of the collar is not the issue, but the risk to be designed out is that of a fire in the unit?
So that would be something for the PIV manufacturer to advise on.
The collar manufacturer could advice on the speed of reaction of the collar, and whether it deals with internal as well as external activation.

Try the specialist forum at https://www.safelincs-forum.co.uk/

In terms of the risk - ie what do you need to guard against, ask your local fire service as they have specialist officers who give advice on this type of thing and the FSO 2005 generally.

 

[freddiemercurystwin]

Shouldn't the PIV be linked to the smoke detectors/fire alarms so they are shut down immediately?

 

[^woody^]

Not normally.

 

[freddiemercurystwin]

Then what stops smoke being pumped through the compartment wall in the event of a fire in the property that hasn't reached the PIV unit and activated the collar then?

 

[RandomGrinch]

A running PIV may be beneficial in a fire; maintaining positive pressure in a communal escape route.
Could there be a need for a fire damper in the duct and interlinks, should the fire be in the PIV space?
Without knowing the details, this strikes me as a situation that requires specialist advice.

 

[Belinda.Gonzalez@eve]

The PIV unit will be connected to a smoke detector/fire alarm and stop running in case of a fire.

I will contact the fire officer and ask for advice.

Thank you.