Retrotec USACE User Manual
Page 388
J12 ENERGY & PROCESS ASSESSMENT PROTOCOL
TABLE J3. COMPARISON OF TYPICAL DESIGNS OF AHU COOLING COILS
WITH NEAR-OPTIMAL RETROFIT STRATEGIES
Parameter
Typical Design
Near-Optimal Design
Draw Through 6 Row
550 FPM
Blow Through 8 Row
350 FPM
Mixed air temperature DB
25 °C
77 °F
25 °C
77 °F
Mixed air temperature WB
18.2 °C
64.8 °F
18.2 °C
64.8 °F
Coil entering DB
25 °C
77 °F
26.4 °C
79.5 °F
Coil entering WB
18.2 °C
64.8 °F
18.9 °C
66 °F
Coil leaving DB
11.4 °C
52.5 °F
12.8 °C
55 °F
Coil leaving WB
10.8 °C
51.5 °F
12.2 °C
54 °F
Air handling unit supply air temperature
12.8 °C
55 °F
12.8 °C
55 °F
Chilled water supply temperature
7.2 °C
45 °F
7.2 °C
45 °F
Chilled water return temperature
12.2 °C
54 °F
20.7 °C
69.2 °F
Chilled water temperature differential
–12.8 °C
9 °F
–4.3 °C
24.2 °F
CHW TD % change
169%
Cooling coil water DP (ft H
2O
)
10.1
8
CC DP % change
–21%
Cooling coil air DP (in wc)
1.26
0.64
CC DP % change
–49%
Coil GPM required
70
24.4
Coil GPM % change
–65%
Total BTUH
315,000
296,000
BTUH % change
(Iess over-dehumidifi cation)
–6%