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Rack Cooling Buying Guide

Close-Coupled Cooling for IT Equipment

Why is cooling IT equipment important?

Cooling IT equipment is essential for optimal system performance. Overheated equipment can malfunction and bring business to a halt, costing you time and money.

Maintaining the proper operating temperature for equipment in a network closet, server room or data center helps prevent equipment damage and expensive downtime.

What is close-coupled cooling?

Close-coupled air conditioning units typically use adjustable louvers or flexible output duct to focus cooling where it's needed most without lowering the temperature of the entire room. These units are located inside, near or between server racks. Because they are near the heat source, the units reduce the distance required for delivery of cold air and removal of hot air, using less electricity to power fans.

Close-coupled solutions also make it easy to reconfigure cooling to handle new equipment or eliminate hot spots. In contrast, traditional perimeter and raised-floor computer room air conditioning systems distribute air to the entire room, making it difficult to remove concentrated heat loads.

Are there different types of close-coupled cooling units?

There are three types of close-coupled cooling solutions:
rack-mounted, portable and row-based.

These solutions can be used individually or in combination, depending on the application. A close-coupled unit may provide primary cooling in a small server room or supplementary cooling in a larger one.

What are the benefits of close-coupled cooling?

Close-coupled cooling brings efficiency and flexibility to your network closet, server room or data center:

Efficiency for Lower Operating Costs

Flexibility for Changing Needs

Close-coupled air conditioning units increase efficiency because they can be placed close to the heat source inside, near or between racks.

The units focus cooling where it's needed most, so you won't waste energy and money lowering the temperature of the entire room.

Close-coupled air conditioning units are modular and scalable.

Retrofit, reconfigure or expand cooling to handle expansion, upgrades, virtualization/consolidation projects, increased power density and new hot spots.

Are close-coupled air conditioning units
difficult to install?

If the air conditioning unit has a built-in evaporator to expel condensation, it does not require an external condenser, refrigerant piping, floor drain or water collection tank. This eliminates the need for a disruptive construction project or the cost of hiring an electrician, plumber or HVAC specialist.

Cooling units that are self-contained support plug-and-play installation. Units should include an exhaust hose to remove hot air from the room through a dropped ceiling, window or return duct.

How large is the area you need to cool? How many racks?

Make sure the air conditioning unit you choose has a cooling capacity (BTU/h)
high enough to adequately cool equipment.


Rack-mounted units work best in server rooms or data centers with one or two racks, as long as the power density remains under 2 kW per rack.


Portable units are ideal for cooling a small server room, up to five racks or a hot spot, which could be an entire rack enclosure or a particular device within the enclosure.


Row-based units are placed in a rack row. The number of units needed depends on your cooling requirements.

Do you need network management?

Cooling units that support network management allow you to add a network card for remote access via Web browser, SNMP, SSH or telnet. You can monitor temperatures, change settings, define threshold warnings, receive alerts, access logs and automate operation from any location.

Remote management gives you the opportunity to identify and address potential issues before they cause downtime.

Do you need unattended operation?

For unattended operation, cooling units should support on/off scheduling. They should also automatically restart with the most recent settings after a power outage.

The automatic restart feature ensures that IT equipment has proper cooling as soon as possible after power is restored.

Is your air conditioning unit
environmentally friendly?

Air conditioning units that use R410A refrigerant are environmentally friendly. R410A refrigerant complies with environmental standards worldwide and does not contribute to ozone layer depletion.

Features & Benefits

Ideal for: Rack cooling Rack/spot cooling Rack cooling Rack row cooling
Area cooling Area cooling Area cooling Area cooling
Backup cooling Backup cooling
Provides efficient close-coupled cooling to prevent IT equipment from overheating
Built-in evaporator prevents condensation from accumulating
Supports plug-and-play installation
Supports network management
Restarts automatically after power outages
Includes exhaust kit to direct warm air to dropped ceiling, window or return duct
120V model available
208V/240V model(s) available
230V model available

Ready to Purchase?

Choose from rack-mounted, portable and row-based cooling solutions for IT equipment.

Why Buy from Eaton?

We know you have many brands to choose from. On the surface, they may all seem alike. It's what you don't see that makes the difference. With Eaton, you get solid engineering, proven reliability and exceptional customer service. All our products undergo rigorous quality control before they are offered for sale, and independent testing agencies verify our products meet or exceed the latest safety and performance standards. Our commitment to quality allows us to back our products with industry-leading warranties and responsive customer service. It's the Eaton difference.


Need help with your purchase?
We're always available to help with questions, including product selection, sizing, installation and product customization. Call us at +1 773-869-1776 or email