18-28-1102.3.1 Discharge piping.

   Pressure relief devices shall discharge to the atmosphere at a location not less than 15 feet (4.522 m) above the adjoining ground level and not less than 20 feet (6.096 m) from an operating window, ventilation opening, fire escape or exit in any building.

18-28-1102.3.2 Sizing.

   Discharge piping shall be sized for simultaneous relief of the maximum quantity of refrigerant in the system, via the sum of the system's pressure relief devices. Systems utilizing different classifications of refrigerant of different pressures shall not have discharge piping interconnected. Discharge piping cannot be smaller than the opening on the relief valve. If run longer than 100 feet (30.48 m), increase pipe one size.

18-28-1103 Refrigeration System Classification.

18-28-1103.1 Refrigerant classification.

   Refrigerants shall be classified in accordance with ASHRAE 34 as listed in Table 18-28-1103.1.

Table 18-28-1103.1
Refrigerant Classification and Amounts

Chemical Refrigerant	Formula	Chemical Name of Blend	Amount of Refrigerant per Occupied Space
			Refrigerant Classification	Pounds per 1,000 cubic feet	ppm	g/m3
R-11 d	CCl3F	trichlorofluoromethane	A1	0.39	1,100	6.2
R-12 d	CCl2F2	dichlorodifluoromethane	A1	5.6	18,000	90
R-13 d	CClF3	chlorotrifluoromethane	A1	–	–	–
R-13B1 d	CBrF3	bromotrifluoromethane	A1	–	–	–
R-14	CF4	tetrafluoromethane (carbon tetrafluoride)	A1	25	110,000	400
R-22	CHClF2	chlorodifluoromethane	A1	13	59,000	210
R-23	CHF3	trifluoromethane (fluoroform)	A1	7.3	41,000	120
R-30	CH2Cl2	dichloromethane (methylene chloride)	B1	–	–	–
R-32	CH2F2	difluoromethane (methylene fluoride)	A2 f	4.8	36,000	77
R-40	CH3Cl	chloromethane (methyl chloride)	B2	–	–	–
R-50	CH4	Methane	A3	–	–	–
R-113 d	CCl2FCClF2	1,1,2-trichloro-1,2,2- trifluoroethane	A1	1.2	2,600	20
R-114 d	CClF2CClF2	1,2-dichloro-1,1,2,2- tetrafluoroethane	A1	8.7	20,000	140
R-115	CClF2CF3	chloropentafluoroethane	A1	47	120,000	760
R-116	CF3CF3	hexafluoroethane	A1	34	97,000	550
R-123	CHCl2CF3	2,2-dichloro-1,1,1- trifluoroethane	B1	3.5	9,100	57
R-124	CHClFCF3	2-chloro-1,1,1,2- tetrafluoroethane	A1	3.5	10,000	56
R-125	CHF2CF3	pentafluoroethane	A1	23	75,000	370
R-134a	CH2FCF3	1,1,1,2-tetrafluoroethane	A1	13	50,000	210
R-141b	CH3CCl2F	1,1-dichloro-1-fluoroethane	–	0.78	2,600	12
R-142b	CH3CClF2	1-chloro-1,1-difluoroethane	A2	5.1	20,000	83
R-143a	CH3CF3	1,1,1-trifluoroethane	A2 f	4.5	21,000	70
R-152a	CH3CHF2	1,1-difluoroethane	A2	2.0	12,000	32
R-170	CH3CH3	Ethane	A3	0.54	7,000	8.7
R-E170	CH3OCH3	Methoxymethane (dimethyl ether)	A3	1.0	8,500	16
R-218	CF3CF2CF3	octafluoropropane	A1	43	90,000	690
R-227ea	CF3CHFCF3	1,1,1,2,3,3,3- heptafluoropropane	A1	36	84,000	580
R-236fa	CF3CH2CF3	1,1,1,3,3,3-hexafluoropropane	A1	21	55,000	340
R-245fa	CHF2CH2CF3	1,1,1,3,3-pentafluoropropane	B1	12	34,000	190
R-290	CH3CH2CH3	propane	A3	0.56	5,300	9.5
R-C318	-(CF2)4-	octafluorocyclobutane	A1	41	80,000	660
R-400 d	zeotrope	R-12/114 (50.0/50.0)	A1	10	28,000	160
R-400 d	zeotrope	R-12/114 (60.0/40.0)	A1	11	30,000	170
R-401A	zeotrope	R-22/152a/124 (53.0/13.0/34.0)	A1	6.6	27,000	110
R-401B	zeotrope	R-22/152a/124 (61.0/11.0/28.0)	A1	7.2	30,000	120
R-401C	zeotrope	R-22/152a/124 (33.0/15.0/52.0)	A1	5.2	20,000	84
R-402A	zeotrope	R-125/290/22 (60.0/2.0/38.0)	A1	17	66,000	270
R-402B	zeotrope	R-125/290/22 (38.0/2.0/60.0)	A1	15	63,000	240
R-403A	zeotrope	R-290/22/218 (5.0/75.0/20.0)	A2	7.6	33,000	120
R-403B	zeotrope	R-290/22/218 (5.0/56.0/39.0)	A1	18	70,000	290
R-404A	zeotrope	R-125/143a/134a (44.0/52.0/4.0)	A1	31	130,000	500
R-405A	zeotrope	R-22/152a/142b/C318 (45.0/7.0/5.5/2.5)	–	16	57,000	260
R-406A	zeotrope	R-22/600a/142b (55.0/4.0/41.0)	A2	4.7	21,000	25
R-407A	zeotrope	R-32/125/134a (20.0/40.0/40.0)	A1	19	83,000	300
R-407B	zeotrope	R-32/125/134a (10.0/70.0/20.0)	A1	21	79,000	330
R-407C	zeotrope	R-32/125/134a (23.0/25.0/52.0)	A1	18	81,000	290
R-407D	zeotrope	R-32/125/134a (15.0/15.0/70.0)	A1	16	68,000	250
R-407E	zeotrope	R-32/125/134a (25.0/15.0/60.0)	A1	17	80,000	280
R-407F	zeotrope	R-32/125/134a (30.0/30.0/40.0)	A1	20	95,000	320
R-407G	zeotrope	R-32/125/134a (2.5/2.5/95.0)	A1	13	52,000	210
R-407H	zeotrope	R-32/125/134a (32.5/15.0/52.5)	A1	19	92,000	300
R-408A	zeotrope	R-125/143a/22 (7.0/46.0/47.0)	A1	21	95,000	340
R-409A	zeotrope	R-22/124/142b (60.0/25.0/15.0)	A1	7.1	29,000	110
R-409B	zeotrope	R-22/124/142b (65.0/25.0/10.0)	A1	7.3	30,000	120
R-410A	zeotrope	R-32/125 (50.0/50.0)	A1	26	140,000	420
R-410B	zeotrope	R-32/125 (45.0/55.0)	A1	27	140,000	430
R-411A	zeotrope	R-127/22/152a (1.5/87.5/11.0)	A2	2.9	14,000	46
R-411B	zeotrope	R-1270/22/152a (3.0/94.0/3.0)	A2	2.8	13,000	45
R-412A	zeotrope	R-22/218/142b (70.0/5.0/25.0)	A2	5.1	22,000	82
R-413A	zeotrope	R-218/134a/600a (9.0/88.0/3.0)	A2	5.8	22,000	94
R-414A	zeotrope	R-22/124/600a/142b (51.0/28.5/4.0/16.5)	A1	6.4	26,000	100
R-414B	zeotrope	R-22/124/600a/142b (50.0/39.0/1.5/9.5)	A1	6.0	23,000	95
R-415A	zeotrope	R-22/152a (82.0/18.0)	A2	2.9	14,000	47
R-415B	zeotrope	R-22/152a (25.0/75.0)	A2	2.1	12,000	34
R-416A	zeotrope	R-134a/124/600 (59.0/39.5/1.5)	A1	3.9	14,000	62
R-417A	zeotrope	R-125/134a/600 (46.6/50.0/3.4)	A1	3.5	13,000	56
R-417B	zeotrope	R-125/134a/600 (79.0/18.3/2.7)	A1	4.3	15,000	70
R-417C	zeotrope	R-125/134a/600 (19.5/78.8/1.7)	A1	5.4	21,000	87
R-418A	zeotrope	R-290/22/152a (1.5/96.0/2.5)	A2	4.8	22,000	77
R-419A	zeotrope	R-125/134a/E170 (77.0/19.0/4.0)	A2	4.2	15,000	67
R-419B	zeotrope	R-125/134a/E170 (48.5/48.0/3.5)	A2	4.6	17,000	74
R-420A	zeotrope	R-134a/142b (88.0/12.0)	A1	12	45,000	190
R-421A	zeotrope	R-125/134a (58.0/42.0)	A1	17	61,000	280
R-421B	zeotrope	R-125/134a (85.0/15.0)	A1	21	69,000	330
R-422A	zeotrope	R-125/134a/600a (85.1/11.5/3.4)	A1	18	63,000	290
R-422B	zeotrope	R-125/134a/600a (55.0/42.0/3.0)	A1	16	56,000	250
R-422C	zeotrope	R-125/134a/600a (82.0/15.0/3.0)	A1	18	62,000	290
R-422D	zeotrope	R-125/134a/600a (65.1/31.5/3.4)	A1	16	58,000	260
R-422E	zeotrope	R-125/134a/600a (58.0/39.3/2.7)	A1	16	57,000	260
R-423A	zeotrope	R-134a/227ea (52.5/47.5)	A1	19	59,000	310
R-424A	zeotrope	R-125/134a/600a/600/601a (50.5/47.0/0.9/1.0/0.6)	A1	6.2	23,000	100
R-425A	zoetrope	R-32/134a/227ea (18.5/69.5/12.0)	A1	16	72,000	260
R-426A	zeotrope	R-125/134a/600a/601a (5.1/93.0/1.3/0.6)	A1	5.2	20,000	83
R-427A	zeotrope	R-32/125/143a/134a (15.0/25.0/10.0/50.0)	A1	18	79,000	290
R-428A	zeotrope	R-125/143a/290/600a (77.5/20.0/0.6/1.9)	A1	23	83,000	370
R-429A	zeotrope	R-E170/152a/600a (60.0/10.0/30.0)	A3	0.81	6,300	13
R-430A	zeotrope	R-152a/600a (76.0/24.0)	A3	1.3	8,000	21
R-431A	zeotrope	R-290/152a (71.0/29.0)	A3	0.69	5,500	11
R-432A	zeotrope	R-1270/E170 (80.0/20.0)	A3	0.13	1,200	2.1
R-433A	zeotrope	R-1270/290 (30.0/70.0)	A3	0.34	3,100	5.5
R-433B	zeotrope	R-1270/290 (5.0-95.0)	A3	0.51	4,500	8.1
R-433C	zeotrope	R-1270/290 (25.0-75.0)	A3	0.41	3,600	6.6
R-434A	zeotrope	R-125/143a/600a (63.2/18.0/16.0/2.8)	A1	20	73,000	320
R-435A	zeotrope	R-E170/152a (80.0/20.0)	A3	1.1	8,500	17
R-436A	zeotrope	R-290/600a (56.0/44.0)	A3	0.50	4,000	8.1
R-436B	zeotrope	R-290/600a (52.0/48.0)	A3	0.51	4,000	8.1
R-437A	zeotrope	R-125/134a/600/601 (19.5/78.5/1.4/0.6)	A1	5.0	19,000	82
R-438A	zeotrope	R-32/125/134a/600/601a (8.5/45.0/44.2/1.7/0.6)	A1	4.9	20,000	79
R-439A	zeotrope	R-32/125/600a (50.0/47.0/3.0)	A2	4.7	26,000	76
R-440A	zeotrope	R-290/134a/152a (0.6/1.6/97.8)	A2	1.9	12,000	31
R-441A	zeotrope	R-170/290/600a/600 (3.1/54.8/6.0/36.1)	A3	0.39	3,200	6.3
R-442A	zeotrope	R-32/125/134a/152a/227ea (31.0/31.0/30.0/3.0/5.0)	A1	21	100,000	330
R-443A	zeotrope	R-1270/290/600a (55.0/40.0/5.0)	A3	0.19	1,700	3.1
R-444A	zeotrope	R-32/152a/1234ze(E) (12.0/5.0/83.0)	A2 f	5.1	21,000	81
R-444B	zeotrope	R-32/152a/1234ze(E) (41.5/10.0/48.5)	A2 f	4.3	23,000	69
R-445A	zeotrope	R-744/134a/1234ze(E) (6.0/9.0/85.0)	A2 f	4.2	16,000	67
R-446A	zeotrope	R-32/1234ze(E)/600 (68.0/29.0/3.0)	A2 f	2.5	16,000	39
R-447A	zeotrope	R-32/125/1234ze(E) (68.0/3.5/28.5)	A2 f	2.6	16,000	42
R-447B	zeotrope	R-32/125/1234ze(E) (68.0/8.0/24.0)	A2 f	23	30,000	360
R-448A	zeotrope	R- 32/125/1234yf/134a/1234ze(E) (26.0/26.0/20.0/21.0/7.0)	A1	24	110,000	390
R-449A	zeotrope	R-32/125/1234yf/134a (24.3/24.7/25.3/25.7)	A1	23	100,000	370
R-450A	zeotrope	R-134a/1234ze(E) (42.0/58.0)	A1	20	72,000	320
R-451A	zeotrope	R-1234yf/134a (89.8/10.2)	A2 f	5.3	18,000	81
R-451B	zeotrope	R-1234yf/134a (88.8/11.2)	A2 f	5.3	18,000	81
R-452A	zeotrope	R-32/125/1234yf (11.0/59.0/30.0)	A1	27	100,000	440
R-452B	zeotrope	R-32/125/1234yf (67.0/7.0/26.0)	A2 f	23	30,000	360
R-452C	zeotrope	R-32/125/1234yf (12.5/61.0/26.5)	A1	27	100,000	430
R-453A	zeotrope	R-32/125/134a/227ea/600/601a (20.0/20.0/53.8/5.0/0.6/0.6)	A1	7.8	34,000	120
R-454A	zeotrope	R-32/1234yf (35.0/65.0)	A2 f	28	16,000	450
R-454B	zeotrope	R-32/1234yf (68.9/31.1)	A2 f	22	19,000	360
R-454C	zeotrope	R-32/1234yf (21.5/78.5)	A2 f	29	19,000	460
R-455A	zeotrope	R-744/32/1234yf (3.0/21.5/75.5)	A2 f	23	30,000	380
R-456A	zeotrope	R-32/134a/1234ze(E) (6.0/45.0/49.0)	A1	20	77,000	320
R-457A	zeotrope	R-32/1234yf/152a (18.0/70.0/12.0)	A2 f	25	15,000	400
R-458A	zeotrope	R-32/125/134a/227ea/236fa (20.5/4.0/61.4/13.5/0.6)	A1	18	76,000	280
R-459A	zeotrope	R-32/1234yf/1234ze(E) (68.0/26.0/6.0)	A2 f	23	27,000	360
R-459B	zeotrope	R-32/1234yf/1234ze(E) (21.0/69.0/10.0)	A2 f	30	16,000	470
R-460A	zeotrope	R-32/125/134a/1234ze(E) (12.0/52.0/14.0/22.0)	A1	24	92,000	380
R-460B	zeotrope	R-32/125/134a/1234ze(E) (28.0/25.0/20.0/27.0)	A1	25	120,000	400
R-461A	zeotrope	R-125/143a/134a/227ea/600a (55.0/5.0/32.0/5.0/3.0)	A1	17	61,000	270
R-462A	zeotrope	R-32/125/143a/134a/600 (9.0/42.0/2.0/44.0/3.0)	A2	3.9	16,000	62
R-463A	zeotrope	R-744/32/125/1234yf/134a (6.0/36.0/30.0/14.0/14.0)	A1	19	98,000	300
R-500	azeotrope	R-12/152a (73.8/26.2)	A1	7.6	30,000	120
R-501 d	azeotrope	R-22/12 (75.0/25.0)	A1	13	54,000	210
R-502	azeotrope	R-22/115 (48.8/51.2)	A1	21	73,000	330
R-503	azeotrope	R-23/13 (40.1/59.9)	–	–	–	–
R-504 d	azeotrope	R-32/115 (48.2/51.8)	–	28	140,000	450
R-507A	azeotrope	R-125/143a (50.0/50.0)	A1	32	130,000	520
R-508A	azeotrope	R-23/116 (39.0/61.0)	A1	14	55,000	220
R-508B	azeotrope	R-23/116 (46.0/54.0)	A1	13	52,000	200
R-509A	azeotrope	R-22/218 (44.0/56.0)	A1	24	75,000	390
R-510A	azeotrope	R-E170/600a (88.0/12.0)	A3	0.87	7,300	14
R-511A	azeotrope	R-290/E170 (95.0/5.0)	A3	0.59	5,300	9.5
R-512A	azeotrope	R-134a/152a (5.0/95.0)	A2	1.9	11,000	31
R-513A	azeotrope	R-1234yf/134a (56.0/44.0)	A1	20	72,000	320
R-600	CH3CH2CH2CH3	butane	A3	0.15	1,000	2.4
R-600a	CH(CH3)2CH3	2-methylpropane (isobutane)	A3	0.59	4,000	9.6
R-601	CH3CH2CH2 CH2CH3	pentane	A3	0.18	1,000	2.9
R-601a	(CH3)2CHCH2CH3	2-methylbutane (isopentane)	A3	0.18	1,000	2.9
R-610	CH3CH2OCH2CH3	ethoxyethane (ethyl ether)	–	–	–	–
R-611	HCOOCH3	methyl formate	B2	–	–	–
R-717	NH3	ammonia	B2 f	0.014	320	0.22
R-718	H2O	water	A1	–	–	–
R-744	CO2	carbon dioxide	A1	4.5	40,000	72
R-1150	CH2=CH2	ethene (ethylene)	A3	–	–	–
R-1233zd(E)	CF3CH=CHCl	trans-1-chloro-3,3,3-trifluoro-1- propene	A1	5.3	16,000	85
R-1234yf	CF3CF=CH2	2,3,3,3-tetrafluoro-1 propene	A2 f	4.7	16,000	75
R-1234ze(E)	CF3CH=CHF	trans-1,3,3,3-tetrafluoro-1- propene	A2 f	4.7	16,000	75
R-1270	CH3CH=CH2	Propene (propylene)	A3	0.1	1,000	1.7

 

For SI: 1 pound = 0.454 kg, 1 cubic foot = 0.0283 m 3

a.   [Reserved]

b.   [Reserved]

c.   [Reserved]

d.   Class I ozone depleting substance; prohibited for new installations.

e.   [Reserved]

f.   The ASHRAE Standard 34 flammability classification for this refrigerant is 2L, which is a subclass of Class 2.

(Amend Coun. J. 9-14-21, p. 35949, Art. XI, § 7)

18-28-1103.2 Occupancy classification.

   Locations of refrigerating systems are described by occupancy classifications that consider the ability of people to respond to potential exposure to refrigerants. Where equipment or appliances, other than piping, are located outside a building and within 20 feet (6096 mm) of any building opening, such equipment or appliances shall be governed by the occupancy classification of the building.

18-28-1103.2.1 Institutional systems – general.

   A refrigeration system installed in buildings, or parts thereof, from which 3 or more occupants cannot readily leave without the assistance of others because they are disabled, debilitated or confined shall be classified as an Institutional System.

(Amend Coun. J. 4-10-19, p. 100029, Art. XII, § 15)

18-28-1103.2.2 Industrial systems – general.

   A refrigeration system used in the manufacturing, processing, or storage of goods such as chemicals, food, ice, meat or petroleum located in a building or parts thereof, that is not open to the public and where access by authorized persons in controlled, shall be classified as an Industrial System.

(Amend Coun. J. 4-10-19, p. 100029, Art. XII, § 16)