Calculating ESFR sprinklers in same compartment as QR Sprinklers

[Haldorson]

A compartment contains both QR standard coverage sprinklers and ESFR sprinklers. The QR standard coverage sprinklers protect a mezzanine that is not separated from the adjacent warehouse protected by ESFR sprinklers.

For the hydraulic calculation at the boundary condition (where ESFR and standard coverage sprinklers are adjacent to each other), what calculation method would apply?

Note: the only sentence I found precluding ESFR sprinklers being adjacent to standard coverage sprinklers is NFPA 13(2013), 8.4.6.4.1 but that is specific to "standard response" sprinklers, not quick response sprinklers.

 

[UFT12]

8.4.6.4.1 does not concern calculations, only installation principles. Speaking of calculations only, one should not affect the other. Just calculate the most demanding 12 ESFRs or more you need to calculate regardless of their location. Similarly, calculate then the QR sprinklers regardless of their location (if supplied by a different group). Your water supply must of course satisfy both duty points. Observe further the requirements of 12.3.

 

[Haldorson]

Both the ESFR and QR sprinklers are off the same zone (same compartment as well).

If the density/area calculation method for the QR sprinklers captures both QR and ESFR sprinklers, then flow both simultaneously?

 

[MatthewJWillis]

As stated above,

You are dealing with TWO different calc areas and TWO different calc methods.

Calc the ESFR, per their criteria.

Then do a Density/Area calc for the mezz.

The Only time you would have combined flow is if rack sprinklers were required as a compliment to the overhead.

R/
Matt