MECHANICAL REFRIGERATION SYSTEMS
INTRODUCTION
Mechanical refrigeration systems such as chillers, air conditioners, and heat pumps containing pressurized refrigerants pose a potential hazard to equipment and personnel from explosion, fire and suffocation. This chapter specifies the procedures to be followed in the design, construction, installation and operation of refrigeration systems which fall under the scope of this chapter. ASHRAE Standard 15-1989 (or current version) is a mandated standard at Fermilab. This chapter attempts to resolve conflicts between ASHRAE 15 and other chapters in the ES&H Manual.
SCOPE
This chapter applies to all mechanical refrigeration systems falling under the scope of ASHRAE 15 but limited to only those fluids listed in Table 1 of the ASHRAE 15 standard. Specifically excluded from the scope of this chapter are any cryogenic systems of any size using a fluid whose normal boiling point is less than -150 deg. C.
SPECIAL RESPONSIBILITIES
The division/section head in which the mechanical refrigeration system is being operated is responsible for carrying out the requirements of this chapter. The ES&H Section shall audit the divisions/sections on their compliance to this chapter.
PROCEDURES
1. Mechanical refrigeration system design, construction, installation, and operation must meet all requirements of ASHRAE 15. A signed document by an individual deemed qualified by the appropriate division/section head must demonstrate that the mechanical refrigeration system meets the requirements of ASHRAE 15.
2. Mechanical refrigeration systems covered by ASHRAE 15 need not comply with ES&H Chapters 5031 (Pressure Vessels), 5031.1 (Pressure Piping Systems), 5031.4 (Inspection and Testing of Relief Systems), 5064 (Oxygen Deficiency Hazards), and 6020.3 (Storage and Use of Flammable Gases at Physics Experiments).
APPENDIX A
Table 1
Refrigerant Classification* and Amounts**
Quantity of Refrigerant
Per Room Volume
Chemical lb. per
Refrigerant Name Formula 1000 ft3*** vol.% kg per m3***
Group 1: R-11 Trichlorofluoromethane CC13F 1.6 0.4 1.025
R-12 Dichlorodifluoromethane CC12F2 12 4.0 0.2
R-13 Chlorotrifluoromethane CC1F3 31 12 0.5
R-13B1 Bromotrifluoromethane CBrF3 22 5.7 0.35
R-14 Tetrafluoromethane CF4 25 11 0.4
R-22 Chlorodifluoromethane CHCIF2 9.4 4.2 0.15
R-113 Trichlorotrifluoroethan CC12FCCIF2 1.9 0.4 0.03
e
R-114 Dichlorotetrafluoroetha CC1F2CC1F2 9.4 2.1 0.15
ne
R-115 Chloropentafluoroethane CC1F2CF3 38 9.4 0.6
R-C318 Octafluorocyclobutane C4F8 50 9.7 0.8
R-400 R-12 and R-114 CC12F2/C2C12 (1) (1) (1)
F4
R500 Dichlorodifluoromethane CC12F2/CH3CH 16 4.7 0.25
, 73.8%, and F2
difluoroethane, 26.2%
R502 Chlorodifluoromethane, CHC1F2/CC1F2 19 6.5 0.3
48.8% and CF3
Chloropentafluoroethane
, 51.2%
R-503 Trifluoromethane, CHF3/CC1F3 25 11 0.4
40.1% and
Chlorotrifluoromethane,
59.9%
R-744 Carbon Dioxide CO2 6.2 5.5 0.1
Group 2: R-40 Methyl Chloride CH3C1 1.9 1.4 0.03
R-611 Methyl Formate HCOOOH3 1.2 0.8 0.02
R-717 Ammonia NH3 - - -
R-764 Sulfur Dioxide SO2 - - -
Group 3a: R-170 Ethane C2H6 0.5 0.64 0.008
R-290 Propane C3H8 0.5 0.44 0.008
R-600 Butane C4H10 0.5 0.34 0.008
R-600a Isobutane CH(CH3)3 0.5 0.34 0.008
R-1150 Ethylene C2H4 0.4 0.52 0.006
R-1270 Propylene C3H6 0.4 0.34 0.006
Group 3b: R-142b 1-Chloro-1-1-Difluoroet CH3CC1F2 3.7 1.4 0.06
hane
R-152a 1,1-Difluoroethane CH3CHF2 1.2 0.7 0.02
Group 4b: R-22 and R142b CHC1F2/CH3CC (1) (1) (1)
1F2
*Group
Classification: Note: These values are being furnished by Standard Project
Committee 34-78R which is revising the 1978 edition of Standard 34.
**To be used only in conjunction with Section 6
(1) The quantity of each component shall comply with the limits set in Table 1 for the pure compound and the total volume % of all components shall not exceed 12 vol. % (see Appendix A).
***To correct for height, H(feet), above sea level, multiply these values by (1- 2.42 x 10-5H). To correct for height, h(km) above sea level, mutliply these values by (1 - 7.94 x 10-2h).
ANSI/ASHRAE STANDARD 15-1989