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General Information
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March 10, 2006
• Vol.28 Issue 10
Page(s) 4 in print issue
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Chilling With Portable AC
Staying Cool In Your Data Center
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Given the static nature of most data centers, cooling infrastructure is often integrated into the physical structure of the building. But what happens when built-in AC isn’t enough to adequately cool the environment or, worse yet, goes down?
The average server puts off approximately 1,200btu, so IT managers know it isn’t long before temperatures can reach critical highs, even to the point of damaging computer systems. When disasters such as an HVAC system failure strike, managers often turn to portable AC units during the interim to maintain safe temperatures in their data centers.
Today IT managers are also more likely to change office configurations, often adding numerous electronics, which generate a significant amount of heat. In older buildings, air conditioning systems were not designed for the high heat load per square foot that the modern wired office presents.
For these reasons, portable AC systems are becoming more popular as alternatives to permanent installations as well as wise investments for HVAC failures. “There’s nothing wrong with buying a portable,” says Mike Renier, vice president of sales for KwiKool. He stresses portables’ cost effectiveness vs. making changes to a permanent system. | 
APC NetworkAIR PA
Starts at $3,195
Portable, self-contained AC units for small rooms and data closets with 1.6kW (0.5-ton) and 4kW (1.2-ton) models
www.Processor.com/APC
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Convenience, flexibility, and ease of use also factor into the choice for portable AC units. “You wheel it in, plug it in, and turn it on. It’s very simple,” says Eddie Stevenson, product marketing manager at MovinCool.
 Size Matters
Prior to purchasing a portable AC unit, it is extremely important to calculate the total heat load. “Improper sizing of air conditioning systems is a disaster,” warns Renier.
Garth Tagge, vice president of sales at Spot Coolers, the leading supplier of portable AC in the United States, explains there are two facets to determining total heat load: heat generated by equipment, which is known as equipment load, and the heat in the room from radiant sources such as electrical wiring, windows, floors, and people, known as room load.
Equipment load can be calculated by adding up the wattage of each device and converting it to btu, a measure of heat. Wattage can be found either in the device’s manual or by multiplying amps with voltage, both often found on the model plate. For example, most servers operate with 120 volts and consume 3 amps, meaning they generate 360 watts. For every watt consumed, 3.41btu are generated. To convert watts to btu, multiply by 3.41, which would result in 1,227btu of heat per hour per server. | 
MovinCool Classic and Office Pro
Starts at $2,100
Offers 12 different models providing cooling capacity ranging from 1 to 5 tons per hour
www.movincool.com
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Calculating room load is also relatively simple. The rule of thumb is a typical commercially built 500-square-foot room with an 8-foot ceiling experiences a ton of room load and therefore requires a ton of cooling. This ton of cooling is for normal room and people loads. Add a copier or any heat-generating equipment, significantly more people than a room is designed for, or windows, and that load increases.
Once the room load is known, you merely add it to the equipment load. This yields your total internal load, or the amount of air conditioning you need to overcome the heat generated within the room.
Tonnage is another term often used when describing heating and cooling capacities. There are 12,000btu in a ton. This means that to cancel out 12,000btu of heat, 1 ton of cooling is required.
Market Leaders
Recognizing that cooling needs happen at all hours of the day and night and on weekends, too, Spot Coolers offers 24-hour service in its 31 locations throughout the United States. It offers both sales and rental turnkey service, including delivery, pickup, and setup, as well as emergency service. | 
KwiKool Strategic Air Center
Starts at $2,350
Offers 32 different models from 1 to 10 tons of capacity in unitary, split-system, and water-cooler units, which will solve most server room air conditioning problems
www.kwikool.com
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Ideal for offices, schools, healthcare, and other facilities with servers, routers, telecom, or other heat-sensitive equipment and workspaces, Spot Coolers has portable air-cooled, water-cooled, and split AC units.
An industry leader in power supply for IT equipment, APC also carries a line of portable cooling units. Designed for office data centers, its NetworkAIR PA line is a self-contained unit not requiring an external condenser, refrigerant piping, or an external water source. Instead, heat is passed through a flexible duct that is easily vented into a dropped ceiling. Additionally, these portable AC units can be assigned a dedicated IP address and managed over the network.
NetworkAIR PA also works as a backup cooling device in the event of primary air conditioning failure by providing up to 4 kilowatts of air conditioning power, set either on an environmental sensor or a timer. This means that if the building reduces the AC during nonbusiness hours, NetworkAIR can compensate by maintaining cooler temperatures in the required areas. | 
Spot Coolers
Starts at $3,300
The largest portable AC supplier in the country with 31 locations; provides portable models ranging in cooling capacity from 1 to 5 tons, including the MovinCool Office Pro 60 pictured above
www.spot-coolers.com
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KwiKool’s Strategic Air Centers work well in both the data center and industrial environments. They offer 32 different models ranging from 1 to 10 tons of cooling capacity in unitary, split-system, and water-cooler units. All models are equipped with microprocessor digital controls accessed via an Easy-Touch control panel. They can also be remotely controlled using a wireless remote thermostat.
Renier credits a major advantage for choosing a Strategic Air Center. “The system needs little or no building modifications, and since it will not be attached to the building and therefore not part of the real property, the customer gets to retain ownership of the unit, not the building.”
Manufactured by DENSO, MovinCool portable AC units have been a staple in data centers for more than 20 years. Originally designed to keep DENSO factory workers cool, the Classic line has changed little from the early models deployed in industrial environments.
Moving into a computer-centric environment, DENSO launched the MovinCool Office Pro series targeted at data centers and offices. In addition to the rugged cooling capabilities of the Classic line, programmable clocks and automation and digital temperature controls have been included in the Office Pro series.
Whether you need a spot cooler to fit through a doorway into a small telecom closet, take over for a failed HVAC in the data center, or put a chill into a specific space, there are plenty of portable AC units available, day or night, to fit your needs. 
by Sandra Kay Miller
Buying Tips
According to Garth Tagge with Spot Coolers, there are a number of variables to consider when considering portable AC units.
• Total heat load from equipment. How much heat does the equipment within the space generate? “The equipment load is almost always the biggest heat source in the room,” says Tagge.
• Secondary heat load from the room. All interior rooms have hidden heat sources referred to as “room loads.” They are a result of heat generated from electrical wires in the walls, lighting, people, radiant heat from windows, and heat from adjacent rooms and floors.
• Condensate disposal. All AC units wring moisture from the air, known as condensate. Considerations have to be made on how the condensate will be removed. Some units have collection buckets that must be frequently emptied. When they fill up, they shut off the AC unit to prevent flooding. Equipment room AC units are typically operated around the clock. Emptying buckets on nights and weekends would require someone to always be there, so most are equipped with a pump to continually dispose of the condensate. “The biggest challenge to adding a pump is finding a source for draining the condensate,” says Tagge.
• Power requirements. The smallest portable AC units operate on 110 volts. As such, they can typically use standard house power. However, units greater than 18,000btu or 1.5 tons use higher voltages, such as 220 or 460 volts. You will want to make sure there is the availability of this power once your loads exceed 1.5 tons.
• Adequate space. Most portable AC units are placed directly in the room to be cooled. You will want to check the room for adequate space for the equipment, as well as ensure that where you place the unit allows for adequate and even airflow. Placing a unit behind something that blocks or deflects the air might create hot spots or even inadvertently shut down the unit. |
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