pressure (log)
enthalpy
dew
dew
Mean
Mean
Condensing temp. limits
80
90
100
110
120
130
140
150
160
-10
0
10
20
30
40
50
60
Evaporating temperature [°F]
Condensing temperature [°F]
S.H. = 20
o
F
S.H. = 54
o
F
SUPERHEAT
Condensing temp. limits
S.H. = 20
o
F
S.H. = 54
o
F
SUPERHEAT
80
90
100
110
120
130
140
150
160
-10
0
10
20
30
40
50
60
Evaporating temperature [°F]
C
o
n
d
en
si
n
g
te
m
p
er
at
u
re
[°
F]
10
application envelopes at
mean temperatures
dew temperature and
mean temperature for
R-407c
opeRating enVelopes
The following operating diagrams
show the difference between mean
and dew temperature application
envelopes.
dew temperature
Mean temperature
Example for SZ 084 to 185
Example for SZ 084 to 185
Refrigerant R-407C is a zeotropic mix-
ture with a temperature glide in both
evaporator and condenser. Therefore,
when discussing evaporating and
condensing temperatures, it is im-
portant to indicate whether these are
DEW POINT values or MEAN values.
In the figure below, the dashed lines
reflect constant temperature and do
not correspond with the constant
pressure lines. For a given cycle, the
MEAN point temperatures are typi-
cally about 3.5° to 5.5°F lower than
DEW point temperatures. In these
Selection and Application Guidelines,
we displays temperatures as DEW
point values.
The performance tables for R-407C
(see p. 6-7) are also based on DEW
point values.
Summary of Contents for Performer SM 084
Page 39: ......
