Conclusion

There is no need to convince the IT professionals, specifying engineers, critical system managers and dat center managers that their environments are changing and have been changing for several years. The need to address the higher density data center is real. Data centers tat were designed at 35 watts per square foot are obsolete and can no longer effectively cool the new generation of servers. Those data centers that were designed and built at 65 watts a square foot are the predominant facility in the country and strategies must be employed to enhance their performance. in doing so, owners will avoid substantial capital costs designing and building new facilities.

With so many companies offering products that will improve the performance of existing data center cooling systems, the end user has several options. These options vary in performance and cost. These options come with different levels of risk to the production environment. As informed decisions are made, the astute professional will weigh the following:

1 – Performance

• Capacity of the existing cooling system.
• Density of new and existing cabinets
• The environmental requirements of existing gear and what the cooling requirements will be in the next 3 years.
• The temperature of the cooling air. Will the air be too cold, such as taking it from directly under a raised floor and cause condensation inside servers.
• The life expectancy of the new equipment

2 – Risk

• The risk of jeopardizing business continuation with the installation of new equipment.
• Will new system enhancements increase the potential for down time such as a water leak, refrigerant leak or lack of redundancy?
• Environment modification such as cutting openings in raised floors, increasing the risk of equipment tipping over, floor tiles cut incorrectly, lessening the floor capacity.

3 – Maintenance

• Can in-house personnel maintain the new cabinets or equipments?
• Will experienced technicians be required to maintain refrigeration or chilled water equipment?
• How much maintenance will be required forcing annual shutdowns?
• Service agreements.
• Additional service technicians working in the data center
• Response time your company will get from a third party service providers in the event of an emergency.

4 – Cost

• Upfront investment
• Installation costs
• Service agreements.
• Routine maintenance
• Financial impact in the event of a failed piece of cooling equipment or water leak.

The products available today vary drastically relating to the above categories. Companies have developed fan systems that mount to the doors of computer cabinets, trying to draw cool air through the servers only to realize the system does not eliminate the temperature gradients at the front of the servers but actually draw warm, mixed air through the servers instead.

Modular A/C units have been designed to sit on to of computer cabinets, delivering 55 degree air into the cabinet. While the cooling intent is realized, there is substantial risk and cost involved, not to mention performance. Putting refrigeration equipment on top of production equipment jeopardizes uptime in so many ways:

• compressor failure,
• wiring or relay problems,
• refrigerant charges,
• technicians climbing on top of gear,
• redundancy

The cost is substantial. Lead time for parts and qualified servicemen all become paramount. 55 degree air delivered to the new generation servers has seen complaints of condensation on processor boards.

Chilled water loops are a new approach to enhance system performance. While cabinet mounted A/C units have a broad range of concerns, putting chilled water lines in a mission critical computer cabinet adds additional risk. While 55 degree air is delivered, the potential for water leaks are very real. Flex lines, hose fittings, valves… all have the potential for leaks. Then look at the water treatment program to ensure proper treatment to prevent pitting and scale buildup. Look at maintenance, service agreements costs and downtime to retrofit your system.

Fans mounted on the tops, bottoms and backs of cabinets, taking cold air from under a raised floor is another attempt to cool gear within computer cabinets. While the air flow patterns are confusing and questionable, temperature gradients are not eliminated. The goal is to deliver the same volume and temperature of cool air to the face of all servers housed in a cabinet. This approach also requires that raised floors be modified, cut out, and a cabinet roller over the opening. Air hits the the bottom server and is blown and or drawn to the top and back of the cabinet. The air is typically 55 degrees and can cause condensing within processing equipment. The cost is reasonable but performance is questionable.

All of the aforementioned approaches have benefits but they also have downsides. An approach that will deliver the coolest air in the room to the face of all the servers housed within a computer cabinet, have minimal or no maintenance required, does not require skilled third party service technicians, does not require raised floors to be modified, eliminates temperature gradients, has no risk to production, ensures redundancy, eliminates air mixing and is cost effective, does exist.

Karis Technologies has this solution with the ability to meet the data center needs of tomorrow.