Data center facilities often consume more than 100 times the power of similarly sized commercial office space due to their special ability to house energy-intensive IT equipment and operate 24 hours a day, 365 days a year. Implementing effective energy-saving measures in data centers along with this large-scale power usage can significantly reduce energy consumption and associated utility costs. A thorough and detailed analysis of every energy saving opportunity must be done to ensure that the total operating cost of the data center is minimized.
Traditional Data Center Opportunities
What actions can existing data center operators explore to achieve greater facility energy efficiency while industry guidelines and standards identify opportunities to implement energy-saving measures in newly built data centers or data centers currently being designed? It’s not an exhaustive list, but opportunities to consider include:
- Energy Usage Monitoring Equipment Installation
Legacy data centers may lack the robust energy usage monitoring equipment and sensors required to comply with ASHRAE standards and collect measurements to calculate data center PUE. The installation of energy monitoring components and systems to measure the energy efficiency of a data center is essential to the effective implementation of all other energy saving measures.
- Optimize Supply Air Temperature
Adjust (increase) the HVAC supply air temperature to create an IT equipment environment that matches the upper limit of the recommended temperature range specified in the ASHRAE Thermal Guidelines for Data Processing Environments. A higher supply air temperature increases the compressor efficiency when a DX type unit is used for cooling or increases the efficiency of the cooling unit when a chilled water air handling unit is used for cooling.
- Optimize Crac Control
The standalone computer room air conditioning (CRAC) units used in legacy data centers often have individual controls and setpoints, resulting in the units “fighting” each other over temperature and humidity regulation, causing the units to run excessively. Broadening the deadband for temperature and humidity settings reduces the tendency of these devices to behave this way.
- Separate Hold And Cold Air
Create a hot aisle/cold aisle layout for your IT equipment to maximize cold air flow to equipment inlets and remove warm exhaust air from equipment racks. You can create a hot aisle or a cold aisle by adding a partition or ceiling to prevent mixing of hot and cold air.
- Improved Floor Pressure Management
For data centers with raised floor plenums, energy efficiency is improved when the raised floor system is properly sealed and unnecessary floor blockage is eliminated. Uncontrolled air leaks from raised floors can result in an inadequate amount of cooling air reaching the IT equipment. Blocked floors or obstructions may result in inadequate cold air flow to the machine. These conditions require a higher HVAC supply air temperature and additional fan energy to handle the equipment cooling load.
- Improve Crac Unit Efficiency
Improvements in the energy efficiency of CRAC units, including the use of variable speed control for the supply air fans and the use of electronic commutation (EC) motors, are standard features of the new CRAC units. You can save energy by retrofitting existing CRAC units or replacing older CRAC units with these features.
- Improving Transformer Efficiency
For data center facilities that contain outdated power distribution components that are nearing the end of their expected useful life, cost-effective energy savings can be achieved by replacing existing standard efficiency electrical transformers with high efficiency transformers. In addition to generating lower internal electrical losses, high-efficiency transformers also generate less waste heat that must be mechanically cooled. Reconfiguring the utility power distribution system to reduce the number of transformers required for replacement can also save energy if possible.
- Improve Lighting Efficiency
For facilities currently illuminated with fluorescent lighting fixtures, significant energy savings can be achieved by replacing or retrofitting with LED-type fixtures. Installing enhanced lighting controls, such as occupancy/motion sensors, or installing additional manual controls to turn off lights when spaces are free can also be cost-effective energy-saving measures.