Ammonia Refrigeration and the 2018 International Building Code

The International Code Council (ICC) recently released their publication of the 2018 International Building Code (IBC) and while this code has less provisions than the Fire or Mechanical Codes that directly impact ammonia refrigeration systems, there are several noteworthy excerpts. If you own or operate an ammonia refrigeration system, we recommend taking note of the upcoming changes:

1. Access to Machinery Rooms

According to 2018 IBC §1006.2.2.2[1] machinery rooms larger than 1,000 ft² must have two exits or exit access doorways. Doorways must be separated by a horizontal distance equal to one-half the maximum horizontal dimension of the room and all portions of the room must be within 150 ft of an exit. Doors must swing in the direction of egress, be tight fitting, and self-closing.

2. Access to Refrigerated Rooms

Similar to machinery rooms, according to 2018 IBC §1006.2.2.3[2], rooms containing an evaporator and maintained below 68°F must have access to not less than two exits or exit access doorways which are accessible within 150 ft of all portions of the room. Egress can be provided through an adjoining room.

3. Occupancy Classification

Facilities with ammonia refrigeration system(s) should not be classified as a High-Hazard Group H occupancy according to 2018 IBC §307.1.1 (Item 7)[3]. We wrote about this in some detail in a previous blog post.

4. Machinery Room Fire Protection

Machinery rooms must be designed for 1-hour fire separation or equipped with an automatic sprinkler system according to 2018 IBC Table 509.

5. Refrigerant Detector

The requirement for a refrigerant detector inside the machinery room which was included in 2015 IBC §908.6 [4], but was removed from 2018 IBC. The 2015 IBC requirement was redundant to the requirement in the 2015 International Mechanical Code (IMC), so the requirement still exists, but it has been isolated to IMC and is no longer included in IBC.

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[1] 2018 IBC §1006.2.2.2 Refrigeration machinery rooms. Machinery rooms larger than 1,000 square feet (93 m²) shall have not less than two exits or exit access doorways. Where two exit access doorways are required, one such doorway is permitted to be served by a fixed ladder or an alternating tread device. Exit access doorways shall be separated by a horizontal distance equal to one-half the maximum horizontal dimension of the room.

All portions of machinery rooms shall be within 150 feet (45 720 mm) of an exit or exit access doorway. An increase in exit access travel distance is permitted in accordance with Section 1017.1.

Exit and exit access doorways shall swing in the direction of egress travel, regardless of the occupant load served. Exit and exit access doorways shall be tight fitting and self-closing.

[2] 2018 IBC §1006.2.2.3 Refrigerated rooms or spaces.

Rooms or spaces having a floor area larger than 1,000 square feet (93 m2), containing a refrigerant evaporator and maintained at a temperature below 68°F (20°C), shall have access to not less than two exits or exit access doorways. Exit access travel distance shall be determined as specified in Section 1017.1, but all portions of a refrigerated room or space shall be within 150 feet (45 720 mm) of an exit or exit access doorway where such rooms are not protected by an approved automatic sprinkler system. Egress is allowed through adjoining refrigerated rooms or spaces.

Exception: Where using refrigerants in quantities limited to the amounts based on the volume set forth in the International Mechanical Code.

[3] 2018 IBC §307.1.1 Uses other than Group H.

An occupancy that stores, uses or handles hazardous materials as described in one or more of the following items shall not be classified as Group H, but shall be classified as the occupancy that it most nearly resembles.

1. Buildings and structures occupied for the application of flammable finishes, provided that such buildings or areas conform to the requirements of Section 416 and the International Fire Code.
2. Wholesale and retail sales and storage of flammable and combustible liquids in mercantile occupancies conforming to the International Fire Code.
3. Closed piping system containing flammable or combustible liquids or gases utilized for the operation of machinery or equipment.
4. Cleaning establishments that utilize combustible liquid solvents having a flash point of 140°F (60°C) or higher in closed systems employing equipment listed by an approved testing agency, provided that this occupancy is separated from all other areas of the building by 1-hour fire barriers constructed in accordance with Section 707 or 1-hour horizontal assemblies constructed in accordance with Section 711, or both.
5. Cleaning establishments that utilize liquid solvent having a flash point at or above 200°F (93°C).
6. Liquor stores and distributors without bulk storage.
7. Refrigeration systems.
8. The storage or utilization of materials for agricultural purposes on the premises.
9. Stationary storage battery systems installed in accordance with the International Fire Code.
10. Corrosive personal or household products in their original packaging used in retail display.
11. Commonly used corrosive building materials.
12. Buildings and structures occupied for aerosol product storage shall be classified as Group S-1, provided that such buildings conform to the requirements of the International Fire Code.
13. Display and storage of nonflammable solid and nonflammable or noncombustible liquid hazardous materials in quantities not exceeding the maximum allowable quantity per control area in Group M or S occupancies complying with Section 414.2.5.
14. The storage of black powder, smokeless propellant and small arms primers in Groups M and R-3 and special industrial explosive devices in Groups B, F, M and S, provided such storage conforms to the quantity limits and requirements prescribed in the International Fire Code.
15. Stationary fuel cell power systems installed in accordance with the International Fire Code.
16. Capacitor energy storage systems in accordance with the International Fire Code.
17. Group B higher education laboratory occupancies complying with Section 428 and Chapter 38 of the International Fire Code.

[4] 2015 IBC §908.6 Refrigerant detector. Machinery rooms shall contain a refrigerant detector with an audible and visual alarm. The detector, or a sampling tube that draws air to the detector, shall be located in an area where refrigerant from a leak will concentrate. The alarm shall be actuated at a value not greater than the corresponding TLV-TWA values for the refrigerant classification shown in the International Mechanical Code for the refrigerant classification. Detectors and alarms shall be placed in approved locations. The detector shall transmit a signal to an approved location.