Baffles, Barriers, Water Shields & “Heat Collectors”. These terms are tossed around on shop drawings & in the field interchangeably. They are different even if the result is similar.

Baffle: Used between sprinklers to prevent cold soldering in lieu of meeting the minimum distance between sprinkler requirements for Standard Pendent, Upright & Sidewall Spray Sprinklers, Extended Coverage Upright Pendent & Sidewall Spray Sprinklers, Residential Sprinklers, CMSA Sprinklers (as of 2022 ed. of NFPA 13), & ESFR Sprinklers (as of 2022 ed. of NFPA 13).

Baffles may be used in lieu of meeting the minimum distance between sprinklers where the following conditions are met:

1.      Baffles shall be arranged to protect the actuating elements.
2.      Baffles shall be made of solid & rigid material that will stay in place before & during sprinkler operation.
3.      Baffles shall be not less than 8 in. long & 6 in. high.
4.      The tops of baffles shall extend between 2 in. & 3 in. above the deflectors of upright sprinklers.
5.      The bottoms of baffles shall extend downward at least even with the deflectors of pendent sprinklers.

Barrier (Horizontal or Vertical): Normally used in open frame racks to limit flame spread & channel heat toward sprinklers that are located between the barriers. Used to limit the scope of the event to an area designed to control the event. May consist of either minimum 22-gauge sheet metal or minimum 3/8 in. plywood. Only installed when required by the protection scheme.

Water Shield: Defined as a horizontal barrier used to protect sprinklers from cold soldering by sprinklers at a higher elevation. Water shields may be integral as in the intermediate-level sprinkler or stand alone as in the use of a barrier (see above) that is doing double duty as a barrier (in an in-rack sprinkler scheme) & a water shield.

Heat Collector: Isolated 2 ft by 2 ft, 2 ft by 4 ft acoustical ceiling tiles, or inverted 9 in. aluminum pie pans with a hole for the sprinkler to project through. Often associated with renovations of airports & high rise office space.

NFPA 13 (2022 ed.) § A. The rules describing the maximum distance permitted for sprinklers below ceilings must be followed. The concept of placing a small “heat collector” above a sprinkler to assist in activation is not appropriate, nor is it contemplated in this standard. There is evidence that objects above a sprinkler will delay the activation of the sprinkler where fires are not directly below the sprinkler (but are still in the coverage area of the sprinkler). One of the objectives of the standard is to cool the ceiling near the structural members with spray from a nearby sprinkler, which is not accomplished by a sprinkler far down from the ceiling, & a heat collector will not help this situation.

Words have meanings. Do you have projects where these words have caused a communication problem?