Table of Contents
Advertisement
Evacuating and Recharging Connections
REFRIGERANT LEAKS
A system with R-134a and Ester oil will become satur-
ated with moisture much faster than a system with
R-12 and mineral oil. The compressor in an R-134a
system will have to be replaced if the product has had a
low side leak.
R-134a refrigerant molecules are smaller than R-12
molecules. This means that R-134a will pass more minor
leaks and the rate of flow will be greater than for R-12.
Therefore, it is now more important than ever to follow
good brazing practices. Use a good grade of silver
solder. 45% silver solder is recommended.
LEAK DETECTION
R-134a system leaks can be pinpointed by means of an
electronic leak detector or by bubble solution.
Electronic leak detectors for R-134a service are currently
available from several manufacturers. The least expensive
models are non-selective detectors that will detect any
type of emission or vapor present, regardless of its
chemical composition. Some non-selective detectors
designed for use with R-12 may have a much lower
sensitivity when used with R-134a. However, newly
designed detectors with good R-134a sensitivity are now
available. Be sure to consult with the manufacturer
before selecting or using a non-selective detector with
R-134a.
Halogen-specific detectors use a specialized sensor
that allows detection of compounds containing chlorine,
fluorine, bromine, and iodine without being activated by
other species. The major advantage of this type of
detector is a reduction in the number of "nuisance
alarms". Halogen-specific detectors are generally more
expensive than non-selective detectors but feature higher
sensitivity.
R-134a PROPERTIES
The properties of R-134a are very similar to those of R12.
The principal data for the two refrigerants are shown in
the chart below.
N
A
M
E
F
r o
m
u
a l
M
o
e l
c
l u
r a
W
e
g i
h
( t
/ g
m
o
O
z
o
n
e
D
e
l p
t e
o i
n
P
o
e t
n
i t
(
O
D
) P
G
o l
b
l a
W
r a
m
n i
g
P
o
e t
n
i t
l a
(
G
W
) P
B
o
l i
n i
g
P
i o
t n
F °
V
a
p
r o
P
e r
s
s
u
e r
7 (
° 7
) F
F
a l
m
m
a
b
i l i
y t
S
o
u l
b
i l i
y t
f o
W
t a
r e
n i
R
e
r f
g i
e
a r
n
( t
w
t
%
@
7
° 7
) F
49
Figure E4
R
E
F
R
G I
E
R
A
N
T
R
1 -
2
R
D
c i
h
o l
o r
i d
u l f
r o
- o
1
1 ,
1 ,
m
e
h t
a
n
e
u l f
o
o r
C
I C
F
C
H
2
2
1
2
0
9 .
3
) l
l a
1
3
1 .
2 -
1
6 .
8
0
p
s
g i
8
N
o
n
e
0
0 .
0
9
S
1 -
3
4
a
2 ,
- -
e T
r t
- a
m
e
h t
a
n
e
F
C -
F
2
3
1
0
2
3 .
0
0
3 .
1 -
5
7 .
2
p
s
g i
N
o
n
e
0
1 .
1
Advertisement
Table of Contents
