My Chevy Volt displays my gas mileage. In fact, I knew what the mileage performance would be before I bought the car. It was a factor in my purchase choice.
In addition to cars, most large appliances display power use along with Energy-Star certification. Residential air conditioners display standard energy efficiency ratings (SEER). Even large commercial building air conditioners have to meet standard rating conditions for efficiency.
Yet, it is only recently that efficiency ratings have been specified for data center cooling. The primary reason is that for years, manufacturers of cooling units for mission critical facilities avoided efficiency ratings requirements claiming that, because their products were used for process cooling versus comfort cooling, efficiency standards shouldn’t apply. Fortunately, ASHRAE took up the charge and updated Standard 90.1 so that equipment covered by ASHRAE Standard 127 is required to meet minimum efficiency standards. Standard 90.1 has been adopted by the Department of Energy as a federal energy standard and is now referenced by many code authorities.
While useful and certainly progress, the choice enabled by these two standards is just a start. Certainly new equipment can and should be compared based on energy efficiency ratings. However we all know that equipment efficiency will vary considerably through use. It would also be useful to be able to view and compare the operational efficiency of existing equipment in order to evaluate which machines are working well, which should be replaced (using the new equipment efficiency ratings as a baseline of comparison) – and how much efficiency could be gained (and calculated from an ROI perspective) through replacement.
Some HVAC manufacturers have taken up this challenge. NTT, for example, provides the coefficient of performance for its computer room air conditioners in real time, viewable on the front panel of each unit and through a communications interface. We commend them.
The ability to compare initial purchase energy efficiency ratings against actual performance over time for a particular machine, gives data center managers the ability to not only track and evaluate a machine for individual performance durability, and compare its performance with that of similar machines. Mechanisms and procedures can be put in place for maintenance as degradation is spotted. Inefficient machines can be used less, fixed or phased out.
We challenge mission critical cooling system manufacturers to pull back the veil of secrecy on energy efficiency. The time for transparency is at hand because this information is knowable. The combination of smart sensors and analytics technology can already report dynamic machine-to-machine efficiency as this information is required to drive cooling optimization. The smart decision is for HVAC manufacturers to get out ahead of this data, and use efficiency reporting as a differentiator and means of driving continual improvement.
Just as mandatory EPA mileage ratings and rising gas prices changed consumer buying decisions – and drove car manufacturers to offer cars with better gas mileage, more granular energy performance ratings will improve the efficiency of cooling equipment. And this benefits all of us.