Who Doesn’t Like Saving Money? By saving Energy A reduction of 4% in data center power consumption can be expected for each degree warmer the temperature is kept. Of course, equipment must be kept within acceptable temperature ranges and never over 75 degrees, even though hardware specifications may rate the equipment to operate at temperatures of up to 95 degrees. Machinery operating outside of the acceptable temperature range wears down more quickly and poses a risk of overheating resulting in possible downtime. An additional problem is created when keeping a server room cooler than surrounding rooms: increased humidity levels. T he recommended humidity levels for data centers are between 45% and 55%. Cooling air too much can increase humidity. Once this happens, condensation can gather within sensitive, essential computer equipment and result in a hardware failure. I focus on, easy-to-implement strategies that can result in instant savings. None of these methods relies on any new technology introductions or expense.
Projects I’ve Completed CRAC units 116 and 117 cooling setpoint increased from 70DegF to 74DegF. (Serves common area.) 8-19-09 CRAC units 118 and 119 cooling setpoint increased from 70DegF to 74DegF. (Serves PDU hallway in phase III) 8-12-09 Humidity setpoint increased from 40%-45% to 45%-55% in meet-me room. CRAC units 98 – 104. This reduced space humidity and allowed the temperature setpoint to be maintained. 8-21-09 Disabled heating on VAV 1 – 4. Currently program uses a narrow .5DegF dead-band between the heating and cooling setpoint. This caused cycling of heat during what should be cooling only mode. Complete 8-5-09 (Program needs to be changed allowing larger dead-band and heating lockout based on outdoor air temperature. WIP) Lighting schedules and motion control enabled in all phases. 8-20-09 Cooling setpoint on both AC units in Power-house increased from 71DegF to 74DegF. 8-13-09 Cooling setpoint on CRAC 105 – 112 serving electrical room increased from 71DegF to 75DegF set to PI control. 9-17-09 Decreased flow in chilled water chemical add tank. Decreased by-pass. 9-2-09 HVAC units LPC01 and LPC02 serving pump room both ran 24x7 and were set to discharge a constant 55DegF supply temp. Changed units to allow single unit operation and rotation. Changed temperature sensor to control space temperature. Setpoint set at 75DegF. 9-17-09 Changed parameters to allow a two (2) chiller operation, when the outdoor temperature is approximately below 65DegF. Was running minimum of three (3) chillers. 10-13-09 Added proportional – integral control to CRAC units, were using proportional control only. 10-19-09. CRAC units in Phase III. Supply air temperature maximum setpoint was set at 60DegF this caused over-cooling and humidity problems. Heating setpoint had been set to 85DegF to try and correct this. Changed Supply air temperature maximum to 70DegF and set heating setpoint to 68DegF. This stopped running heat on the CRAC units 24 x 7, reduced load to chiller plant and improved humidity control. 10-23-09 $126,144.00 per year (estimated for not running heat) Changed BAS system to only run 4 of the 8 CRAC units in the electrical room. 11-18-09 $20,912.00 per year (estimated) Removed 30 perforated floor tiles from phase 3 reduced the amount of CRAC units running by 2. VFD command reduced from 58.7Hz to 47.2Hz 12-18-09 $19,089.00 per year (estimated) All estimates are using .08 per KWH .
I’m not done yet………….. Chiller loading, increase load setpoint to add chiller, etc. WIP Lower chilled water differential setpoint. Lights off in pump and electrical rooms. Heating lock-out all office areas. Move all night-shift personal to one office area to increase shutdown schedule of AHU 117. All CRAC units, change humidity setpoint. Currently set to 40% to 45%. Recommended is 45% to 55%. Calibrate temperature and humidity on all CRAC units. WIP Use X belts on all HVAC equipment. Estimated 6% reduction of motor energy. Increase floor temp of data center. Recommended is 70DegF to 75DegF. Currently set at 71DegF. Increase to 72DegF or 73DegF. Motion sensors in restrooms. Eliminate all direct mixing between chilled water supply and return. (elimination of de-coupler by-pass) Remove perforated floor tiles and reduce number of CRAC units. WIP Identify Strategic Locations for Thermostats. In most legacy data centers, thermostats are installed in the CRAC return air stream, where air flow may be unpredictable. This can result in uneven CRAC unit loading, which in turn leads to variations in server inlet temperatures. Relocating the thermostats to the supply air stream, where discharge air can be controlled, will provide more uniform under-floor and server inlet temperatures. Relocating the thermostat also enables discharge air temperatures to be increased with more control and accuracy.
That’s how I work for free. There’s more to me than working for free……………