In the quest to become more energy efficient, or "green" as the buzzword goes, Data Center operators have many considerations and variables to keep on their radar. The implementation of these processes can be a multi-faceted project and typically requires both engineering and management insight to accomplish a variety of goals. With that said, according to the 2011 ASHRAE Thermal Guidelines for Data Processing environments, there are 5-6 separate classes of data center environments. Each class is separated by two factors, the equipment present in the environment, as well as the environmental control that is needed relative to the equipment.
|A1 ||DC Enterprise Servers and Storage ||Tightly controlled environment |
|A2 ||DC Volume Servers, Storage, PCs and Workstations || Some control |
|A3 ||DC Volume Servers, Storage, PCs and Workstations || Some control |
|A4 ||DC Volume Servers, Storage, PCs and Workstations || Some control |
|B ||Office PCs, Workstations, Laptops, Printers || Minimal control |
|C || POS equipment, Computers, PDAs || No Control |
One important note, that while classes A1-A4 may utilize the same types of equipment, the differentiation is important for the segmented environmental specifications, including Dry-Bulb Temperature, Humidity Ranges, Dew Points and Elevation. All of these specifications vary within classes A1-A4, as well as for B and C (Table 4, ASHRAE Guidelines).
After environmental conditions and hardware have been specified, operators must pay strict attention to a long list of considerations for energy optimization. The cliché "attention to detail" is relevant in this case, given the variety of options for optimization. Operators need to consider the big picture first and foremost, but cannot ignore the incremental choices that can also provide value. The following is an abridged version of the list, but provides some of the basic planning considerations for an energy efficient data center. Architecture:
- Layout and Arrangement of the Data Center
- Economizer Airflow Path
- Synchronization of newer buildings with older sections
- Economizer Choice: Water-side, Air-Side, None
- Cooling Routines (in racks or alongside equipment, sensor location)
Type of Data Center
- High Performance Computing (HPC)
- Internet/Web Applications
- Enterprise storage/servers
Temperature and Humidity Ratings:
- Power Distribution Equipment
- Network Gear and Hardware
- Cooling units
- Personnel health
As a general rule of thumb, ensuring the ratings for all equipment is necessary in the larger picture, as the capabilities of equipment may vary significantly under different environmental conditions. If possible, establish a baseline rating for the equipment (and future purchases) to simplify management and planning.
As an aside, the concept of "Waste Heat" is a particularly interesting idea. The concept is based on applying hot server air to other processes that require a certain amount of heat, thereby making use of the supposed "waste heat". This is the same idea as recycling. Ventilation air (for the building), heating water, and a number of other internal processes require some amount of heat. By using "Waste Heat", the server air becomes positive reinforcement for other processes, rather than a drawback. For further information on Reusable energy, or the "Energy Reuse Efficectiveness" (ERE), visitTheGreenGrid.org.
For additional information on 'Green Data Centers', energy efficiency, and ASHRAE guidelines, refer to the compiled Thermal Guidelines or the ASHRAE homepage.