IT equipment is faster and hotter
Managing cooling and power efficiencies has been challenging for data center designers for quite some time. This is due to the significant loads required for the centers to operate effectively. IT equipment manufactured today is substantially smaller and faster, but more importantly to designers, the power density of the system is high, therefore generating significant excess heat. Temperature increases in data centers are a risk to reliability. Although modern data centers have greatly improved their energy efficiency, improvements in power usage efficiency (PUE) can still be achieved in the future through various cooling design methods.
Power Usage Efficiency (PUE)
Originally conceived by Green Grid, an organization that works to advance public policies for the tech sector, PUE is a metric used to determine the energy efficiency of a data center. Expressed as a ratio, PUE is the amount of power required to manage the data center versus the power necessary for the IT equipment.
PUE = (Total Facility Energy) / (IT Equipment Energy)
A data center’s PUE improves as the ratio decreases toward 1. The average power usage effectiveness (PUE) ratio for a data center in 2020 is 1.58, only marginally better than 7 years ago, according to the latest annual Uptime Institute survey. This means that for each single power unit consumed from IT equipment the data center will have 0.53 units of power consumed by support equipment. Assuming the UPS has standard heat loss of ~4-5% and the transformer remains unchanged, AZZ design engineers emphasize advanced cooling techniques to lower PUE.
Cooling design factors
The traditional approach of forcing cool air from a raised floor is not only costly but inefficient for modern data centers in lieu of more sophisticated cooling techniques. AZZ engineers begin the design process by evaluating the location of the data center in terms of the temperature ranges, relative humidity, altitude and other pertinent ambient air records that would impact the performance of the cooling design. Utilizing American Society of Heating and Air-Conditioning Engineers (ASHRAE) data center equipment environmental specifications, AZZ design engineers seek to optimize cooling efficiency by combining alternatives such as direct and indirect cooling, chilling with air or water, refrigerant condensing, and other heat exchanging methods to maximize PUE reductions in the initial data center calculations.
Total Lifetime Value of PUE Reductions
AZZ engineers custom design data centers to optimize the cooling coefficients from exterior ambient temperature striving to reduce operating expenditures (OPEX) and while reducing capital expenditures (CAPEX). By optimizing a variety of mechanical improvements, PUE reductions can significantly progress IT capacity of electrical equipment. Lowering PUE not only reduces utility OPEX, but it also contributes to lowering CAPEX, which can greatly improve the return on investment. By reducing the PUE by 3 basis points, data center operators can save hundreds of thousands of dollars annually.
AZZ Enclosure Systems – Faster to Site, Stronger to Protect
As one of the largest and most experienced specialty enclosure manufacturers in North America, AZZ Enclosure Systems is ready to serve your specific needs. From the harshest environments to the most unique applications, our quality and custom-engineered enclosure systems keep equipment at peak performance and extend operating life. Find out more about our engineered enclosure solutions at azz.com/Enclosures or follow us on LinkedIn.
 Lawrence, Andy. Uptime Institute. Data center PUE flat since 2013. April 27, 2020.