Application Envelopes At Mean Temperatures - Danfoss Performer SM Series Selection & Application Manuallines

opeRating enVelopes
application envelopes at
mean temperatures
dew temperature and
mean temperature for
R-407c
dew temperature
Example for SZ 084 to 185
Mean temperature
Example for SZ 084 to 185
10
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 (log)
Mean
The following operating diagrams
show the difference between mean
160
Condensing temp. limits
150
140
130
120
S.H. = 20 o F
110
100
90
80
-10 0 10 20
Evaporating temperature [°F]
160
150
Condensing temp. limits
140
130
120
S.H. = 20 o F
110
100
90
80
-10 0 10 20
Evaporating temperature [°F]
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.
Mean
dew
dew
enthalpy
and dew temperature application
envelopes.
S.H. = 54 o F
SUPERHEAT
30 40 50 60
S.H. = 54 o F
SUPERHEAT
30 40 50 60