Delta's CW/CWU chilled water cooling system provides precise temperature and humidity control for data centers. It is available in multiple configurations including downflow or upflow designs, integrated or underfloor fans, and standard or high heat exchanger densities. The system features highly efficient EC fans and evaporator coils, dual independent cooling circuits for flexibility and reliability, and advanced controls. Capacities range from 50 to 280 kW.

1. DeltaChilled water cooling for
mission-critical applications
High energy efficiency
allow significant ecomony in large-scale installations
Standard | High density selection
for different heat density applications
Single | Dual cooling circuits
more flexibility and higher reliability with two independent chilled water circuits
Delta CW/CWU
Chilled water air conditioning units with integrated or underfloor fans compartment
Available in 10 frame sizes with integrated or underfloor fan compartments, 30 models in total
Capacity range:
50-280kW
www.kaltra.de Kaltra Innovativtechnik GmbH
Max-Reger-Str. 44 · 90571 Schwaig · Deutschland
October 2015
EC-FANS FREECOOLINGCHILLED WATER UPFLOW DOWNFLOW

2. TechnologyDelta CW/CWU close control cooling system provides precise and reliable control of indoor temperature,
humidity and airflow for proper operation of IT equipment in the data centers.
The customers may select from down or top air discharge designs, enclosures with integrated or underfloor fans,
as well as from models with normal (50-225kW) or enlarged (65-280kW) heat exchangers.
Precise thermal control
Fluid circuits equipped with smart balancing system based on continuous pressure drop measurements on return and
bypass lines. Depending on these measurements, the unit control system adjusts two-way valves and maintains
necessary cooling media flow thru the cooling coils, thus avoiding manual fluid circuit balancing.
Delta’s automatic balancing system fits ideally for variable-flow chilled water systems. Fliud circuit with 3-way regulat-
ing valve for constant flow chilled water systems available as an option.
Dual cooling circuit design provides thermal management from two independent chilled water sources and gives a
wide range of configurations with a focus on either energy efficiency or system reliability.
The Delta’s control system manages the system by activating cooling circuits in accordance to user settings.
Fluid circuits
Delta CW/CWU family features fin-tube evaporators with small-diameter inner grooved copper tubes and
state-of-the-art aluminium fins. Inner grooving increases the internal surface space, while the groove’s torsion
promotes turbulent flow, better cooling media mixing, and eliminate cooling media mal-distribution, resulting in
improved evaporator performance. Small tube diameter requires less cooling media volume and can withstand
higher pressures. The fin geometry has been optimized to achieve improved heat transfer, while retaining low airside
pressure drops.
The laboratory experiments were showed that evaporator coils manufactured using small-diameter tubing reduced
tube weight by 35%, fin weight by 30%, and lowered internal coil volume by 40% compared to previous genera-
tion.
The unit construction allows easy access to the evaporator for maintenance and cleaning.
High-efficient evaporator
www.kaltra.de 1
Delta CW/CWU features the new radial fans with unique blade
geometry and offers more airflow by smaller size and wide efficiency
range. In combination with EC-motors with integrated control function-
ality, communication interface and overtemperature protection, these
fans provide unbeatable energy efficiency, maximum flexibility, and
lowest possible sound emission. The EC motor technology provide
significant savings at both full-load and part-load operation.
Delta’s EC-motors are maintenance free and have a longer lifetime in
comparison to brushed motors.
EC fans

3. Corefeatures
Key data & features
A wide array of options and accessories are available to choose from, giving our customers the possibility to
tailor the Delta CW/CWU to create exactly the cooling solution they need.
Advanced control software features with network connectivity interfaces provides flexible system management -
either local or remote - by connecting the cooling units to the BMS network.
Unit identification
2 www.kaltra.de
Package, options and accessories
Enclosure
size
F1
F2
F3
F4
F5
F6
F4U
F5U
F6U
F7U
Length
mm
1295
1625
1875
2175
2495
2895
2175
2495
2895
3495
Width
mm
925
925
925
925
925
925
925
925
925
925
Width
mm
1985
1985
1985
1985
1985
1985
2575
2575
2575
2575
Designation
Integrated fan compartment (CW)
Underfloor fan compartment (CWU)
Air discharge
Upflow (U)
Downflow (D)
Evaporator
Standard density (S)
High density (H)
Circuits No. of circuits
Delta CW D S125 / 2
Features
Fluidside
2-way regulating valve
3-way regulating valve
2-way regulating valve + 2-way balancing valve
Dual chilled water circuit
Airside
EC-fans w/ enh. functionality
AC-fans
Continuous temperature control
Continuous pressure control
Differential pressure switch
Power & controls
Dual power supply changeover switch
Controller emergency power supply
General
Steam humidification system
Dehumidification system
Motorized backdraft damper
Floorstand
Features
Heating coil w/ 2-way regulating valve
Temperature probes on fluid inlet/outlet
Test connections on fluid inlet/outlet
Fluid leak detection
Air intake/discharge temperature probes
External temperature/humidity probes
G4 air filtration w/ filter change switch
F5 air filtration w/ filter change switch
Fire/smoke detection
BMS connectivity
SNMP connectivity
Multi-stage electric heater w/ thyristor control
Condensate discharge system
Thermal/noise insulation
Air intake plenum
CW
■
□
□
□
■
□
■
□
□
□
□
□
□
□
□
CWU
■
□
□
□
■
□
■
□
□
□
□
□
□
□
CW
□
■
■
□
■
□
■
□
□
■
□
□
□
□
□
CWU
□
■
■
□
■
□
■
□
□
■
□
□
□
□
□
■
□
Standard feature
Optional feature

4. Technical specifications
2016 Kaltra Innovativtechnik GmbH©
Kaltra Innovativtechnik GmbH
Max-Reger-Str. 44 · 90571 Schwaig · Deutschland
E-mail: info@kaltra.de
Tel.: +49 911 715 320 21
24/7 Service & Support Hotline:
+49 152 343 915 17
The development of Kaltra products and services is continuous and the information in this document may not be up to date.
It is important to check the current position with Kaltra at the address stated below:
www.kaltra.de 3
kW
kW
m³/h
kW
A
m³/h
kPa
kW/kW
kW/kW
CW
up/down
S95
1/2
52.8
52.8
F1
1
integrated
13000
2.06
4.2
9.1
55
25.6
25.6
CW
up/down
S125
1/2
71.5
71.5
F2
2
integrated
16400
2.78
8.4
12.2
74
25.7
25.7
CW
up/down
S150
1/2
80.8
80.8
F3
2
integrated
20000
3.32
8.8
14.0
52
24.3
24.3
CW
up/down
S180
1/2
100.0
100.0
F4
2
integrated
24000
3.80
8.6
17.2
82
26.3
26.3
CW
up/down
S215
1/2
120.0
105.0
F5
3
integrated
28500
6.04
12.6
20.5
82
19.9
17.4
CW
up/down
S255
1/2
138.0
128.0
F6
3
integrated
33000
6.20
13.3
23.6
75
22.3
20.6
CWU
down
S180
1/2
125.0
108.0
F4U
3
underfloor
30000
6.36
12.6
21.5
65
19.7
17.0
CWU
down
S215
1/2
148.0
135.0
F5U
3
underfloor
33900
6.12
13.3
25.4
92
24.2
22.1
CWU
down
S255
1/2
172.0
172.0
F6U
3
underfloor
40800
6.70
12.9
29.5
92
25.7
25.7
CWU
down
S315
1/2
225.0
225.0
F7U
4
underfloor
52000
8.36
17.2
38.8
92
26.9
26.9
Delta CW/CWU Standard density
Designation
Air discharge
Evaporator size
No. of circuits
Cooling capacity (single-circuit)
Cooling capacity (dual-circuit)
Enclosure size
EC Fans
Quantity
Arrangement
Airflow
Power input
Current
Fluid circuit(s)
Water flow
Pressure drop
Energy efficiency
EER (single-circuit)
EER (dual-circuit)
7/12°C 100% water
24°C/50%rH inlet air
kW
m³/h
kW
A
m³/h
kPa
kW/kW
CW
up/down
H95
1
65.5
F1
1
integrated
13000
2.48
4.2
13.3
65
26.4
CW
up/down
H125
1
88.0
F2
2
integrated
16400
3.24
8.4
15.0
70
27.2
CW
up/down
H150
1
110.0
F3
2
integrated
20000
3.92
8.8
18.8
80
28.1
CW
up/down
H180
1
125.0
F4
2
integrated
24000
4.66
8.6
21.4
55
26.8
CW
up/down
H215
1
150.0
F5
3
integrated
28500
7.00
12.6
25.6
82
21.4
CW
up/down
H255
1
173.0
F6
3
integrated
33000
7.25
13.3
29.5
82
23.9
CWU
down
H180
1
152.0
F4U
3
underfloor
30000
6.70
12.6
26.0
65
22.7
CWU
down
H215
1
180.0
F5U
3
underfloor
33900
6.70
13.3
31.0
95
26.9
CWU
down
H255
1
212.0
F6U
3
underfloor
40800
7.45
12.9
36.3
45
25.7
CWU
down
H315
1
280.0
F7U
4
underfloor
52000
10.00
17.2
48.0
85
28.0
Delta CW/CWU High density
Designation
Air discharge
Evaporator size
No. of circuits
Cooling capacity
Enclosure size
EC Fans
Quantity
Arrangement
Airflow
Power input
Current
Fluid circuit(s)
Water flow
Pressure drop
Energy efficiency
EER
7/12°C 100% water
24°C/50%rH inlet air