sprinklernotes
Drum Drips in Freezers
You asked the following question: “We have a project where we are installing a
dry system in a freezer. Is there a specific reference in the standard that
would exempt the drum drips from being located inside freezers?”
In response to your question(s) below, we have reviewed NFPA 13, Standard for
the Installation of Sprinkler Systems, 2019 edition.
Our informal interpretation is that auxiliary drains are required to be
installed on dry pipe systems per section 16.10.5.3. For trapped portions in
excess of 5 gal, a drum drip would be required. The only additional provision
for areas subject to freezing is that the drum drip has to be accessible per
section 16.10.5.3.1.
For a dry system installed within a freezer, the chance that moisture would
make it from the discharge of the air supply to a drum drip before freezing is
minimal; however, the current prescriptive requirements dictate that a drum
drip must be installed. With that being said, manufacturers such as AGF
Manufacturing, Inc. make drains with insulated and heated enclosures to prevent
freezing of the water to facilitate draining. AFSA technical staff has flagged
this issue and intends to pursue a change for the 2025 edition of NFPA 13 to
require the drain, but omit the drum drip assembly in areas that are maintained
below 32 °F.
