About this chapter: Mechanical systems are a key element of any building. Chapter 28 regulates such systems by linking to the International Mechanical Code® and International Fuel Gas Code®, where details of mechanical system requirements are provided.
The provisions of this chapter and the Mechanical Code shall govern the design, construction, erection and installation of mechanical appliances, equipment and systems used in buildings and structures covered by this code. Masonry chimneys, fireplaces and barbecues shall comply with the Mechanical Code and Chapter 21 of this code. The Mechanical Code shall govern the use and maintenance of mechanical components, appliances, equipment and systems. The Mechanical Code shall govern the alteration, repair, relocation, replacement and addition of mechanical components, appliances, equipment and systems.
- 660 gallons (2498 L) in unsprinklered buildings, where stored in a tank complying with UL 80, UL 142 or UL 2085.
- 1,320 gallons (4997 L) in buildings equipped with an automatic sprinkler system in accordance with Section 903.3.1.1, where stored in a tank complying with UL 142.
- 3,000 gallons (11 356 L) where stored in protected above-ground tanks complying with UL 2085 and Section 4188.8.131.52.5, and the room is protected by an automatic sprinkler system in accordance with Section 903.3.1.1.
- The corresponding TLV-TWA values provided in the Mechanical Code for the refrigerant classification.
- Twenty-five percent of the lower flammable limit (LFL).
- Directly, where the building official determines, on review of an engineering analysis, that a fire, health or environmental hazard would not result from atmospheric discharge of ammonia. The engineering analysis shall be prepared without charge to the jurisdiction, by a qualified engineer, specialist, laboratory or safety specialty organization acceptable to the building official. The analysis shall be prepared by and bear the stamp of a registered design professional.
- Through an approved treatment system in accordance with Section 2802.5.5.
- Through a flaring system in accordance with Section 2802.5.6.
- Through an approved ammonia diffusion system in accordance with Section 2802.5.7.
- By other approved means.
Exception: Ammonia/water absorption systems containing less than 22 pounds (10 kg) of ammonia and for which the ammonia circuit is located entirely outdoors.
The refrigerant detection system shall be in accordance with Section 2802.3 and all of the following:
|REFRIGERANT||Q (m3/sec)||Q (cfm)|