Unit installation

CDU Installation Guide Page 11
Cooling Distribution Unit
TECHNICAL DATA (continued)
3.7 Primary Circuit
The graphs above are a guide for the primary water requirements, based on the number of RDHx’s
connected for either plain water or up to 30% ethylene glycol (different % of glycol can be estimated on a
pro-rata basis). The primary water should fall either on the chosen curve or in the area above the curve.
Note: The water flow should not be more than 20% above the recommended value for stable control.
Both the graphs are based around a secondary supply temperature of 18°C (64.4°F) to achieve the full
duty of 20kW per RDHx for the 120kW CDU & 25kW per RDHx for the 150kW CDU.
Note: To keep pipe
velocities within
limits, it is
recommended that
the brown shaded
area is avoided.
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
39 41 43 45 47 49 51
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
4 5 6 7 8 9 10 11
Flow (Usgpm)
Temperature (
o
F)
Flow (L/M)
Temperature (
o
C)
Primary Flow/Temperature Graph for 120kW CDUs
1 RDHx (water)
1 RDHx (30% glycol)
2 RDHx (water)
2 RDHx (30% glycol)
3 RDHx (water)
3 RDHx (30% glycol)
4 RDHX (water)
4 RDHx (30% glycol)
5 RDHx (water)
5 RDHx (30% glycol)
6 RDHx (water)
6 RDHx (30% glycol)
0
5
10
15
20
25
30
35
40
45
50
55
39 41 43 45 47 49 51
0
20
40
60
80
100
120
140
160
180
200
220
4 5 6 7 8 9 10 11
Flow (USgpm)
Temperature (
o
F)
Flow (L/M)
Temperature (
o
C)
Primary Flow/Temperature Graph for 150kW CDUs
1 RDHx (water)
1 RDHx (30% glycol)
2 RDHx (water)
2 RDHx (30% glycol)
3 RDHx (water)
3 RDHx (30% glycol)
4 RDHx (water)
4 RDHx (30% glycol)
5 RDHx (water)
5 RDHx (30% glycol)
6 RDHx (water)
6 RDHx (30% glycol)