the relation between K factor and ceiling high

[Riyadh1985]

hi
what is the relation between K factor and ceiling high in non-storage occupancies?

is there any reference about that in NFPA Book?

 

[MatthewJWillis]

In a Non-Storage?
What exactly are you referencing?
I ask, because there are variations to each.

R/
Matt

 

[Riyadh1985]

for example
mall with ceiling high of 15 m
room with 3 m ceiling high and thus

does sprinkler with K-5.6 work for different ceiling high?

 

[MatthewJWillis]

Ah..,

A lot depends on which Code/Standard you have to use.
Previously there was an exception that allowed sprinklers to be omitted above 55'. This dis-appeared.
I must defer to others as to current codes, but as of now,, I do not know of any allowances or restrictions with relation to K vs Height.
I know there is some real concern as to A.D.D (Actual Delivered Density), where the water droplets may not be able to penetrate a plume that high.
I have not seen any data or models.

 

[skdesigner]

FM Global uses the term "nonstorage". FM Datasheet 2-0, Table 3 gives a ceiling height of 30'-0 as a threshold above which it appears 5.6k is no longer an option.


R M Arsenault Engineering Inc.

http://www.rmae.ca

 

[Riyadh1985]

dear engr skdesigner..

NFPA also uses the term "non-storage" >> see NFPA-13 8.17.5.1.3(6)..

 

[TravisMack]

NFPA 13 does not have a correlation to ceiling height and k-factor in non-storage applications. As mentioned above, there is some direction in the FM datasheets to help with ceiling heights and such in those applications where you may be concerned. However, it must be noted that FM is a standalone guide from NFPA 13. If you choose to use exceptions allowed in FM datasheets, you will most likely be required to comply with all of the FM requirements. You can't just pick and choose what you want from NFPA 13 and what you want from FM datasheets, unless the FM guidelines exceed NFPA 13 minimums.

I think it would be prudent to go with the higher k-factors that FM requires in higher ceiling areas. Afterall, NFPA 13 is a MINIMUM standard. You can always exceed the minimums.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

https://www.facebook.com/pages/MFP-Design-LLC/92218417692

 

[RedlineFP]

Riyadh1985,

You might want to check FM DS 2-0 (Table 3 - Page 15) for reference.
Have not come across any guideline related to Ceiling heights and K factor in NFPA though.

 

[Riyadh1985]

thanks guys