Ammonia Detection in Non-Machinery Rooms
Question: Is ammonia detection required in rooms that contain ammonia, but are not classified as machinery rooms?
Answer: This depends on which codes and standards the refrigeration system is subject to. New ammonia refrigeration systems are required to have ammonia detection in both machinery rooms and non-machinery rooms that contain ammonia equipment. Since IIAR Standard 9 does not require detection in non-machinery rooms, older systems may not require detection, unless the design codes and standards adhered to when the system was installed requires it.
New Ammonia Refrigeration Systems
For all new ammonia refrigeration systems, the design of the system should follow the requirements in ANSI/IIAR 2-2021. This standard requires that ammonia detection be installed in machinery rooms, and in non-machinery rooms that contain ammonia equipment.
ANSI/IIAR 2-2021 §7.2.3 Detection and Alarms.
Level 1 detection and alarm will be provided in accordance with Section 17.7.1. the detection and alarm system shall comply with Chapter 17.
Exceptions:
- Unoccupied areas with continuous piping that has been joined by welding and does not include valves, valve assemblies, equipment, or equipment connections do not require level 1 detection and alarm.
- Where not prohibited by the AHJ, rooms or areas in industrial occupancies that are normally occupied 24 hours/day and are regularly patrolled when the rooms’ functions are idled for scheduled downtime and are provided with an alternative to fixed detection and alarm equipment do not require level 1 detection an alarm. A means for emergency notification initiation of alarm response in accordance with Section 17.7.1 shall be provided.
- Where not prohibited by the AHJ, alternatives to fixed ammonia detectors shall be permitted with high committee other harsh environmental conditions they are incompatible with detection devices. A means for emergency notification and initiation of alarm response in accordance with Section 17.7.1 shall be provided.
ANSI/IIAR 2-2021 §17.1 Scope
Ammonia leak detection alarms located in “Machinery Rooms” shall comply with Section 6.13 and Sections 17.2-17.6 of this chapter. Ammonia leak detection and alarms in “Areas Other than Machinery Rooms” shall comply with Section 7.2.3 or Section 7.3.1.2.3, as applicable, and this chapter. Ammonia leak detection in alarms for “Packaged Systems” shall comply with Section 14.4 and this chapter.
Existing Ammonia Refrigeration Systems
For existing ammonia refrigeration systems, it is important to first determine which design codes and standards were followed during the system construction. If these are unknown, then existing systems must at minimum follow the requirements in ANSI/IIAR 9-2020 “Standard for Minimum System Safety Requirements for Existing Closed-Circuit Ammonia Refrigeration Systems”.
ANSI/IIAR 9-2020 does not require ammonia detection to be installed in non-machinery rooms. It does specify that ammonia detectors must be installed in machinery rooms and lists the following requirements in §7.3.12.1:
“Machinery rooms shall be provided with ammonia detection and alarms with the following features:
1) At least one ammonia detector shall be provided in the room or area
2) The detector shall activate an alarm that reports to a monitored location so that corrective action can be taken
3) Audible and visual alarms shall be provided inside the room. Additional audible and visual alarms shall be located outside of each entrance to the machinery room”
However, it should be noted that the Appendix A states that “Ammonia detection in areas other than machinery rooms is not required by IIAR 9. However, ammonia detection may be required in areas other than machinery rooms by the Building Code, Fire Code, or Mechanical Code in effect at the time of installation. In addition, the current version of IIAR 2 (ANSI/IIAR 2-2014 Addendum A) specifies that ammonia detection be provided in areas other than machinery rooms for all new construction unless the exceptions listed in IIAR 2 are met.”
In many cases, existing ammonia refrigeration systems were built in accordance with one of the codes or standards listed in the table below. Many of those listed do not make mention of non-machinery rooms that require ammonia detectors.
| Code/Standard | Detection Required? | Code Reference | |
| Machinery Rooms | Non-Machinery Rooms | ||
| 1998-2013 CMC | Yes | Yes | §1105.3.1/§1104.3.1 |
| 1994-2012 UMC | Yes | Yes | §1105.3.1/§1104.3.1 |
| 2000-2018 IMC | Yes | No | §1104.2.2 |
| 2007-2016 CFC | Yes | No | §606.8 |
| 2015 NFPA 1 | Yes | No | §53.2.3.1 |
| 1994 UFC | Yes | No | §6310.4 |
| 2012-2018 IFC | Yes | No | §605.8 |
| 2016 CBC | Yes | No | §908.6 |
| 2015 IBC | Yes | No | §908.6 |
| 1978-2008 IIAR 2 | Yes | No | §13.2 |
| 2014 IIAR 2 | Yes | Yes | §17.1 |
| 1994-2016 ASHRAE 15 | Yes | No | §8.11.2.1 |
For more details regarding ammonia detection requirements, check out some of our other blogs:
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