Answer: Sprinklers do, in fact, need to be installed over the freezers. Check out NFPA 13’s 2010 edition’s Section 8.15.22 (and associated subsections). The need for sprinklers to extend into the adjacent space by 0.6 times the square root of the sprinkler system’s design area is described in Section 8.15.22.3. For a further example of the design arrangement, see Figure A.8.15.22.3.

Answer: Even in cases of protected light and conventional danger occupancies, the spacing and obstruction standards for the ESFR sprinklers remain applicable, according to the specifications in the 2016 edition of NFPA 13.

The chapter 10 provision to apply the spray sprinkler spacing and obstruction criteria was not included until the 2022 version. That being stated, it is not unusual for an AHJ to approve the use of the most recent version of NFPA 13, particularly in cases where the adopted edition lacked the particular requirements at issue. The obstruction mentioned can be avoided if the AHJ gives its approval to apply the 2022 criterion.

Answer: Not really. A baffle installed in accordance with Section 11.3.4.4 is not continuous, as Section 11.3.4.1.4 requires, in our view. This part mandates that a “continuous lintel, soffit, or baffle” must divide back-to-back Extended Coverage sprinkler installations.

Recall that the continuous baffle, soffit, or lintel serves two purposes. The soffit, or baffle, makes sure the sprinkler closest to the fire runs and that sprinklers on both sides don’t run at the same time. For instance, the sprinkler on the opposite side of the partition (spraying away from the fire) shouldn’t work if a fire breaks out on one side. This would merely divert attention away from the required sprinkler and be of no use. Furthermore, sidewall sprinklers are intended to release some of their spray behind the sprinkler, hence, in the absence of a separation, one sprinkler discharging could result in the cold soldering of the sprinkler next to it. Obviously, the fire may not be contained if the sprinkler facing the fire area is not working because of the spray from the sprinkler next to it.

Considering the aforementioned, a basic baffle in compliance with 11.3.4.4 would not be enough to capture the heat and guarantee that the right sidewall sprinkler turns on. In our view, the back-to-back sprinklers should be put tight to the ceiling and separated continuously (across the bay) to capture the heat from a fire.

Finally, it should be mentioned that section 10.3.4.1.4.2 for regular spray sidewall sprinklers does require that the spacing between back-to-back sidewalls project a minimum of 4 in. (below the deflector), even if it is not covered in the extended coverage chapter (Chapter 11).

Answer: No, quick response sprinkler design area is not included in Factory Mutual (FM) data sheets.

Reduction and/or the NFPA 13 room design approach. FM Radio Non-storage occupancy data sheet 3-26 Table 2 and Section 2.3.1.10 for an HC-1 sprinkler system with wet pipes does offer note 1, which states that, if fire compartmentation with a minimum one-hour fire rating is present, the demand area for dormitories, residential, and dwelling type areas may be based on the largest room area, but not fewer than four sprinklers.

Answer: Section 14.9.2 identifies the important thresholds mentioned in Section 14.9.1, including:

Critical water temperatures:

• Water temperature below 40 degrees Fahrenheit – Section 14.9.2 (1).
• Returning the water temperature to 40°F – Section 14.9.2(2)
• Critical water levels are 3 inches for pressure tanks and 12 inches for all other tanks, as per Section 14.9.2(3).
• Water level returns to normal – Section 14.9.2(4).
• For pressure tanks, critical pressure readings include a pressure 10 psi below normal, as per Section 14.9.2(5).
• The pressure in the pressure tank is 10 psi higher than normal – Section 14.9.2(6).

Answer: According to Annex figure A.9.2.3.4.4(b), tightening the hanger rod to the piping can prevent the end-of-line pendent sprinkler from moving upwards. Hanger manufacturers offer restraining clips to prevent pipes from sliding upward.

This annex figure depicts examples of appropriate hangers for avoiding upward movement.

Answer: There is no known acceptable fire pump startup time. For automatic controllers, NFPA 20, 2022 edition, Section 10.5.2 mandates that the fire pump activates according to pressure drop rather than a predetermined period of time. The fire pump must kick on right away if there is a five-pound pressure drop below the jockey pump start pressure in the system. Once more, there is no time restriction that we are aware of for this automatic pressure activation.

On installations with an automatic transfer switch and an alternate source of power, NFPA 20, 2022 edition, Section 14.2.8 for alternate power supply states that loss of primary source shall be simulated and transfer shall occur when the pump is working at peak load. The handbook commentary explains that the transfer switch and the backup power source should be reached in ten seconds, and the peak flow should be successfully redelivered in twenty to thirty seconds when the primary power source is cut off while flowing at 150 percent of the rated pump capacity.

Answer: This section intends for the stair tower to be entirely noncombustible.

According to NFPA 13, 2019 edition, Section 9.3.4.2.4, sprinklers can be left off of outside stair towers if the tower is made completely of noncombustible materials and its outer walls are at least 50% open.

In this instance, the linked structure may be of combustible construction, provided the stair tower is 50% open and made entirely of noncombustible materials.

Answer: Indeed, using antifreeze and tenting together would be a reasonable way to prevent freezing. Nothing expressly stated in NFPA 13 qualifies this as a violation.

Answer: Section 5.3.4.4.1 of the 2023 version of NFPA 25 allows designated antifreeze solutions to be used beyond the parameters for which they were first authorized. The purpose of this clause, as explained in Annex A.5.3.4.4.1, is to make it easier to switch from older listed antifreeze solutions like glycerin and propylene glycol to newer ones in systems that might not meet the volume and specific requirements for hydraulic design criteria. This is the case as long as the listing limits for the new antifreeze solution cover the required freeze protection temperature.

The draft modifications for the presently being developed 2026 edition include the system volume restriction within the enforceable regulations. The first draft (see FR-27) says that listed antifreeze solutions can be used outside of their recommended system volume and hydraulic calculation limits as long as the operational temperature ranges are not exceeded. This is as long as the Authority Having Jurisdiction (AHJ) agrees. Here’s the initial draft wording (also attached):

“Where acceptable to the AHJ, listed antifreeze solutions used to replace non-listed antifreeze solutions shall be permitted to be utilized outside their system volume and hydraulic calculation limitations if the temperature ranges are not exceeded.”

To sum up, the purpose of these rules does not always call for the system to be divided into several risers to meet the volume limitations of the listed antifreeze.

Instead, it allows the use of designated antifreeze in systems that are bigger than what is listed, as long as the AHJ agrees (the 2023 version does not need the AHJ’s approval), which protects the integrity of current systems without having to reduce their size. The goal behind documenting this method is to keep current systems functional while switching to safer, specified antifreeze options.

Answer: NFPA 13, 2022 edition, Section 9.1.1 requires sprinklers to be installed throughout the premises. This provision requires sprinklers to be put throughout the building, unless the standard specifies otherwise. Sprinklers cannot be removed from areas such as minarets or church steeples, according to the law.

Section 9.2 specifies the permitted sprinkler omission locations. The minaret may meet the standards in Section 9.2.1 that allow sprinklers to be omitted from concealed spaces, depending on its construction and access.

Answer: Sprinkler water will reach both sides of the baffles due to their location below the sprinklers. Because baffles are not structural components, they are not subject to the “three-times” requirement outlined in Section 8.6.5.2.1.4. The answer would alter if the baffle was close to the ceiling or if the fixture’s top was above the deflector plane. The installation as shown looks to be compliant.