Handbook of air conditioning and refrigeration / Shan K

50
50
13.0
27.14
40
40
60
60
50
50
s
70
ss
s
70
13.5
60
60
(a)
90%
(b)
70
80%
70
80
ca, l
ca, l ca, e
80
90%
80%
78/66%
r
75/45%
r
70%
80
60%
14.0
90
90
93/70
60%
o
93/60
50%
50%
40%
20%
40%
30%
20%
100
80 90 100
FIGURE 27.4 Operating characteristics of an indirect-direct two-stage evaporative cooling system: (a) using outdoor
air as cooled air and wet air; (b) using 30 percent outdoor air and 70 percent recirculating air mixture as cooled air and
return air as wet air.
s
r
ca, l
o
o
w, lb/lb
0.020
0.016
0.012
0.008
0.004
w, lb/lb
0.016
0.012
0.008
0.004
100