Key considerations to implement high ambient data center

Abstract

Based on the Forest & Sullivan market survey. Data centers across the globe now consume around 100GWh of power and this number is expected to increase by 30% by 2016. With growth trends increasing and development expanding, IDC owners realize that small improvements in efficiency, from architecture design to daily operations, will yield large cost reductions over time. Cooling energy is a significant part of the daily operational expense of an IDC. One trend in this industry is to raise the operational temperature of an IDC, which also means running IT equipment at higher ambient temperature (HTA) environment. This might also include cooling improvements such as water-side or air-side economizers which can be used in place of traditional closed loop CRAC systems. The more efficient systems can typically be run for much of the year, and energy consumption is saved by avoiding running of the Chiller component. The conventional method of calculating the benefit of higher operational temperature is just to find the balance between the IT power consumption and IDC cooling energy savings. The performance of specific business application and long term reliability of key components do not get enough attention and is not studied carefully. This paper tries to list all important aspects we should consider in an HTA environment, and tries to find the key points and inflection points of running an IDC more efficiently. This paper lists the main challenges IT infrastructure when implementing high operational temperatures in an IDC, and describes the strategy of dealing with those challenges. An important trend seen in industry today is customized IT infrastructure designs for IT equipment and IDC infrastructure from the cloud service provider. This trend brings an opportunity to consider IT and IDC together when designing and IDC, from the early design phase to the daily operation phase, when faced with the challenge of improving efficiency. This trend also provides a chance to get more potential benefit out of higher operational temperatures. The advantages and key components that make up a customized rack server design include reduced power consumption, more thermal margin with less fan power, and accurate thermal monitoring, etc. Accordingly, the specific IDC infrastructure can be redesigned to meet high temperature operation. The chiller will not be the primary cooling source anymore and the BMS system will also be re-designed to setup the communication between IT equipment and IDC cooling equipment. To raise the supply air temperature always means less thermal headroom for IT equipment. This equates to less allowable temperature variation with cooling infrastructure. IDC operators will have less responses time with large power variations or any IDC failures happen. In this paper, we will introduce the new solution like ODC (on-demand cooling) and PTAS to show how those solutions meet these challenges. These solutions use the real time thermal data of IT equipment as the key input data for the cooling controls versus traditional ceiling installed sensors. This new method helps to improve the cooling control accuracy, decrease the response time and reduce temperature variation. By establishing a smart thermal operation like this, one can next explore implementing an aggressive thermal management control policy confident that there is thermal safety in doing so.