sprinklernotes Control Mode Density/Area Sprinklers “When applying Control Mode Density/Area (CMDA) design per Table 21.6.1(b), do you have to use sprinklers that are specifically Listed as CMDA?”
We have reviewed NFPA 13, Standard for the Installation of Sprinkler Systems, 2019 edition as the applicable standard. Our informal interpretation is that the sprinklers are not required to be Listed as CMDA. Standard response sprinklers are acceptable and would only need to be Listed for use in storage applications if the design density exceeds 0.34 gpm/ft2. The use of standard spray sprinklers for storage applications has been applied for quite some time. The use of the term “control mode density/area” may not be indicated on the manufacturer’s data sheet and does not disqualify its use. There was a definition added to the 2016 edition as follows: 3.6.4.1* Control Mode Density/Area (CMDA) Sprinkler. A type of spray sprinkler intended to provide fire control in storage applications using the design density/area criteria described in this standard. NFPA 13 requires the use of Listed storage sprinklers for densities exceeding 0.34 gpm/ft2 per Section 21.1.4; however, lower densities are permitted to use a standard response sprinkler that is not Listed for storage applications per Section 21.1.2 and 21.1.2.3. Where modifications are being made to an existing system, Section 21.1.5 indicates that unless a design density of 0.6 gpm/ft2 over 2,000 ft2 is being used, the requirements of Table 21.5.1.1 shall not apply when using sprinklers with K-factors of K-8.0 or less.
