Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-1 The ozone layer is in the stratosphere, and it blocks ultraviolet rays from the sun. CFCs from R-12 can cause a depletion of and holes in the ozone layer.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-2 The ozone-rich stratosphere protects us from harmful rays coming from the sun. CFC that is vented can break down this layer.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-3 When CFC molecules break down in the stratosphere, a chlorine atom breaks free to attack ozone molecules. (Courtesy of Chrysler LLC)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-4 Greenhouse gases in the lower atmosphere reflect heat back onto Earth and increase temperatures. (Courtesy of Chrysler LLC)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-5 A comparison of environmental concerns for present and future refrigerants.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-6 The time scale adopted at the Montreal Protocol was amended to speed up the phase out of CFCs. (Courtesy of Castrol North America)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-7 Recovery systems remove the refrigerant from a system so it can be recycled. Most are on a cart for easy movement to the vehicle (a).A schematic of the internal portion is shown in (b). (Courtesy of Robinair Division, SPX Corporation)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-8 A refrigerant identifier can be used to determine whether the refrigerant in a system is pure or contaminated. (Courtesy of Neutronics Inc.)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-9 The circled portion of this recovery tank reads “Retest by 02.”

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-10 The remaining refrigerant after charging a system is called the heel; it might leak out of the can.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-11 R-12 and R-134a have similar operating pressures. (Courtesy of Zexel USA Corporation)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-12 A comparison of potential atmospheric damage of refrigerants and flushing agents. (Reprinted with permission from SAE Document M-106, © 1992, Society of Automotive Engineers, Inc.)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-13 A comparison of R-12 and R-134a; note differences in container and fittings. (Courtesy of Nissan Motor Corporation in USA)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-14 A disposable container of R-12 (a). As mentioned on the printed portion (b), this container should not be reused.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-15 A DOT-approved refrigerant container has two valves, one for gas and one for liquid (a). A portion of the upper band reads “DOT-4BA400 (b).

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-16 The pressure–temperature relationship varies between these EPA-approved SNAP refrigerants.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-17 This table shows how various refrigerants affect the elastomer seal materials commonly used in an A/C system. (Courtesy of Santech Industries, Fort Worth,Texas)

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-18 A secondary loop A/C system keeps the potentially dangerous HC refrigerant out of the passenger compartment by using a chiller/heat exchanger to cool an antifreeze and water mixture. This fluid then transfers heat from the cooling core in the air distribution section to the chiller.

Automotive Heating and Air Conditioning, Fifth Edition By Tom Birch © 2010 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ FIGURE 5-19 (a) Pressure in a refrigerant container follows the pressure–temperature relationship until the contents expand to fill the container. (b) When recovering refrigerant, the container should be filled to a maximum of about 80%.