Lambda In-Row CW II

State-of-the-art row level cooling solution for data center applications. Ensures precise thermal management, optimum airflow distribution, and delivers a large cooling capacity



Powerful and flexible solution for data center cooling

With the rapid development of cloud computing and mobile internet, the growth of computing power and energy consumption significantly increases the heat load density in data centers, and this trend will be observed in the foreseeable future.


Today’s data centers require effective cooling systems in order to function while allowing for growth, and Lambda In-Row CW II is the solution.

Compared to its competitors, Lambda In-Row CW II offers an exceptionally high cooling capacity and aims to make savings in many ways, including in improved energy efficiency, simplifying chilled water pipework and power distribution network and related installation investments, reduced number of units and data center footprint needed to meet the same cooling requirement.


Lambda In-Row CW II delivers optimum air distribution across rack installations thanks to the Air Management System (AMS) with regulated airfoil baffles incorporated in the front door. Excellent level of air distribution has been proven as a result of extensive laboratory study and field tests.

* referring to chilled water of 15/21°C and inlet air of 40°C/25%

180kW/m² cooling density*


New in-row cooling units

Large capacity and improved PUE

Separating hot and cold air flows, as well as placing the cooling system closer to the heat source, leads to improved power usage effectiveness (PUE), and
we designed Lambda In-Row to fit any existing aisle containment solution.

Save data center whitespace

In data centers, every centimeter counts. Data center whitespace is highly expensive, and with the new high-capacity Lambda In-Row system it is possible to reduce the number of installed cooling units by more than fourfold compared to the range of similar solutions.

Microchannel evaporators

New Lambda In-Row CW II features microchannel cooling coils with a remarkably better heat transfer performance and significantly lower air resistance.


Microchannel tubes brazed together with louvered fins using a controlled atmosphere brazing furnace have a perfect and permanent contact between tubes and fins, assuring an efficient heat transfer. The small hydraulic diameter of the microchannel tubes and high efficiency of louvered fins further improves the heat transfer performance. The flat geometry of microchannel tubes results in reduced aerodynamic drag while minimizing the air shadow on the back side of the tube. The end effect is the reduced air side pressure drop.


Aluminium microchannel coils are lightweight, robust and have significantly lower internal volume, resulting in lower unit weight and simplified design.


Easy startup

The unit terminal with a large touchscreen display provides advanced control and detailed run statistics and analysis for the operator. The new Android-based software allows configuring multiple Lambda In-Row CW II simultaneously by replicating the configuration and parameters onto a group of networked units thus reducing commissioning time.


With the smart balancing system which includes automated 2-way bypass valve, Lambda In-Row CW II unit adjusts the water flow through the cooling coils, thus performing an automatic balancing previously completed by commissioning engineers.

Free cooling operation

When coupled to chiller system with a free cooling circuit, Lambda In-Row CW II system able to run up to 98% of the time in free cooling mode, thus saving a significant amount of energy.


In data center applications the cooling air temperature can be elevated to 27°C without negative impact on electronic equipment. In connection with the increase in cooling air temperature, the chilled water temperature can also be increased, thus generating greater free cooling opportunities.


For further power savings, we recommend using Lambda In-Row CW II units with air-cooled Lightstream Freecool chillers for large-scale use and water-cooled Easystream chillers which can be installed indoor or outdoor for small to medium data center applications.

In-row unit internals


The control hub of Lambda In-Row CW II is a sophisticated microprocessor with control logic specially developed for row-based cooling units. The customer can manage and optimize the unit’s performance either locally or remotely.


Users can apply various control strategies based on either continuous temperature control, or on-demand airflow control (optional), or constant pressure control by maintaining a pressure differential between the cold and hot aisles (optional).


Lambda In-Row CW II adopted the new generation microchannel technology for the cooling coils. To enlarge the heat exchanging surface, the coils are combined in a single, air-tight V-shaped bank. The geometry of V-bank has been optimized with CFD simulations to achieve an optimum airflow and minimum air resistance.

Cooling coils can be easily cleaned with compressed air without stopping the unit.


Lambda In-Row CW II delivers optimum, CFD modeled air distribution across rack installations thank Air Management System (AMS) with regulated airfoil baffles incorporated in the front door.


The new generation of EC fans reduces power consumption by up to 20% while efficiently managing the high volume flow – it also works at a reduced operating noise level.


Ultra-thin G2 grade air filters have been engineered for high-velocity applications and deliver excellent air quality and low air resistance throughout the service life of the air filter. The filter panels feature fibers which do not absorb moisture nor do they support microbial growth.


Water circuit of Lambda In-Row CW II unit equipped with a smart balancing system based on continuous pressure drop measurements on return and bypass lines. Depending on these measures, the unit control system adjusts two-way valves and maintains necessary water flow thru the cooling coils in variable-flow chilled water systems.

Rack monitoring and remote control

The cooling unit continually monitors thermal parameters of up to 16 racks by reading from temperature sensors installed on air inlets and outlets. When the temperature inside the controlled server racks rises above the set point, the control system issues an alert via the local area network to which the cooling unit is connected, as well as via Android-based software for remote control.

Dewpoint control

The control system of Lambda In-Row CW II cooling unit continuously monitors the air temperature and humidity to minimize condensate build-up by regulating water flow through the evaporator coils. The system eliminates the possibility of condensate spills by means of dewpoint control and automatic condensate discharge system.

Network operation

Local area network (LAN) can be used to connect up to 16 Lambda In-Row CW II units for synchronized operation and run/standby control. With the networked operation, various scenarios can be deployed depending on operational requirements, including unit rotation, load distribution, energy use minimization, etc.

Hot-swappable fans


For cooling equipment used in mission-critical or 24/7 environments, redundant and hot-swap components are essential. Lambda In-Row CW II features hot-swap fan assemblies that facilitate the fan replacement on running units without disrupting the service. When the fan goes offline, the remaining fans will compensate the lack of airflow by increasing the rotation speed.




Power consumption






Fan type

Radial EC

Heat exchangers


Rack thermal control




Related products



High energy efficient in-row cooling units for data center applications equipped with microchannel evaporators and dual chilled water circuit to ensure precise thermal control and accurate circuit balancing

  • facebook-aaaaaa
  • linkedin-aaaaaa
  • twitter-aaaaaa
  • googleplus-aaaaaa

Kaltra Innovativtechnik GmbH

Max-Reger-Str. 44
90571 Schwaig

+49(0)911 715 32021

VAT: DE300943964

Kaltra is a customer-focused developer and supplier of reliable, energy efficient thermal management equipment and solutions.


From the professionalism of our research and development engineers to the wide experience of our service team, we are dedicated to delivering you the best service possible.

Read more

© 2014-2019 Kaltra. All rights reserved.