Subaru Forester Air Conditioning System 1999 2000 (6) PDF

D: HANDLING OF REFRIGERANT
Because refrigerant boils at approx. ?30C (?22F)
at sea level, it is cold enough to give you severe
frostbite. Always wear goggles to protect your eyes
and gloves to protect your hands.Also, even under
the pressures normally found in CFC-12
containers, refrigerant will boil with the addition of
heat. This could raise the pressure inside the con-
tainer to a dangerous level.
Never expose a can of HFC-134a to direct
sunlight, or to temperatures over 40C (104F).
One more thing to remember about HFC-134a is
that when it is exposed to an open flame or to hot
metal, it forms phosgene, a deadly gas. Do not
discharge HFC-134a into the atmosphere on pur-
pose. Always read and follow the precautions on
the HFC-134a bottle.
G4M0979
2. Basic Information
1) The combination of moisture and refrigerant
forms acid, therefore, moisture should not be
allowed to enter the refrigerant.
2) Refrigerant oil readily absorbs moisture,
therefore, keep refrigerant oil containers tightly
capped.
3) The process of evacuating the system is per-
formed to remove small amounts of moisture. This
is accomplished by lowering the pressure inside
the system, which allows the moisture to boil off, in
much the same way that a pot of water will boil
away to nothing given enough time. The evacua-
tion process does not suck the moisture out of the
system.
4) A minimum level of vacuum must be reached to
satisfactorily evacuate the system. This minimum
level of vacuum depends on the temperature
inside the system. The chart below shows the level
of vacuum required to boil water at various tem-
peratures.
Additionally, the vacuum level shown on a gauge
will read approx. 3.3 kPa (25 mmHg, 1 inHg) less
for each 304.8 m (1,000 ft) above sea level, due to
the decrease in atmospheric pressure at altitude.
Vacuum level required to boil water (at sea level)
Temperature Vacuum
1.7C (35F) 100.9 kPa (757 mmHg, 29.8 inHg)
7.2C (45F) 100.6 kPa (754 mmHg, 29.7 inHg)
12.8C (55F) 99.9 kPa (749 mmHg, 29.5 inHg)
18.3C (65F) 99.2 kPa (744 mmHg, 29.3 inHg)
23.9C (75F) 98.5 kPa (739 mmHg, 29.1 inHg)
29.4C (85F) 97.2 kPa (729 mmHg, 28.7 inHg)
35C (95F) 95.8 kPa (719 mmHg, 28.3 inHg)
7
[W200] 4-7SERVICE PROCEDURE
2. Basic Information

Subaru Forester Air Conditioning System 1999 2000 (6) Summary of Content

D: HANDLING OF REFRIGERANTBecause refrigerant boils at approx. 30C (22F)at sea level, it is cold enough to give you severefrostbite. Always wear goggles to protect your eyesand gloves to protect your hands.Also, even underthe pressures normally found in CFC-12containers, refrigerant will boil with the addition ofheat. This could raise the pressure inside the con-tainer to a dangerous level.Never expose a can of HFC-134a to directsunlight, or to temperatures over 40C (104F).One more thing to remember about HFC-134a isthat when it is exposed to an open flame or to hotmetal, it forms phosgene, a deadly gas. Do notdischarge HFC-134a into the atmosphere on pur-pose. Always read and follow the precautions onthe HFC-134a bottle.G4M09792. Basic Information1) The combination of moisture and refrigerantforms acid, therefore, moisture should not beallowed to enter the refrigerant.2) Refrigerant oil readily absorbs moisture,therefore, keep refrigerant oil containers tightlycapped.3) The process of evacuating the system is per-formed to remove small amounts of moisture. Thisis accomplished by lowering the pressure insidethe system, which allows the moisture to boil off, inmuch the same way that a pot of water will boilaway to nothing given enough time. The evacua-tion process does not suck the moisture out of thesystem.4) A minimum level of vacuum must be reached tosatisfactorily evacuate the system. This minimumlevel of vacuum depends on the temperatureinside the system. The chart below shows the levelof vacuum required to boil water at various tem-peratures.Additionally, the vacuum level shown on a gaugewill read approx. 3.3 kPa (25 mmHg, 1 inHg) lessfor each 304.8 m (1,000 ft) above sea level, due tothe decrease in atmospheric pressure at altitude.Vacuum level required to boil water (at sea level)Temperature Vacuum1.7C (35F) 100.9 kPa (757 mmHg, 29.8 inHg)7.2C (45F) 100.6 kPa (754 mmHg, 29.7 inHg)12.8C (55F) 99.9 kPa (749 mmHg, 29.5 inHg)18.3C (65F) 99.2 kPa (744 mmHg, 29.3 inHg)23.9C (75F) 98.5 kPa (739 mmHg, 29.1 inHg)29.4C (85F) 97.2 kPa (729 mmHg, 28.7 inHg)35C (95F) 95.8 kPa (719 mmHg, 28.3 inHg)7[W200] 4-7SERVICE PROCEDURE2. Basic Information