Green computing initiatives for small to medium sized organizations.

• Author: Mamaghani, Farrokh
• Position: Report

1. INTRODUCTION

   More and more small and medium size companies worldwide have opened their eyes to the potential benefits of "Going Green." However, what does it mean to go green for companies and their IT organizations? Green IT/Green computing can be defined as "the study and practice of designing, manufacturing, using, and disposing of computers, servers, and associated subsystems--such as monitors, printers, storage devices, and networking and communications systems--efficiently and effectively with minimal or no impact on the environment." (Murugesan, 2008). Knowing what is involved, it is easy to become overwhelmed with ideas when presented with such a broad spectrum of green initiatives. Throughout this paper, we will focus on the benefits of green computing for those organizations with less than 500 employees.

   A company that utilizes ENERGY STAR rated LCD monitors with sleep settings activated, over the course of four years, saves an estimated $42,445 versus a company that is still utilizing conventional LCD monitors (http://www.sba.gov/content/energy-saving-calculators-energy-star). In addition to the monetary savings, green computing has an immediate and lasting positive impact on our environment. Green computing lessons our reliance on the earth's natural resources and it also has the ability to reduce dangerous green house carbon emissions. With a well thought out implementation plan, it is possible to take gradual steps towards an eco-friendly, functional business model. It is important however to realize, that a company new to green computing should plan on implementing ideas in stages and measure results over time. This paper will cover methods and recommendations for green computing and the appropriate metrics to measure progress.

2. DATA CENTER ENVIRONMENTAL DESIGN CONSIDERATIONS

   There are many design alternatives when considering existing data center or planning a new one. One of the largest cost concerns for any data center is energy consumption. These concerns are generated from the electricity necessary to power hardware which includes storage devices and servers as well as the energy utilized to keep the data center at a consistent temperature. Knowing these concerns leads to the first data center design consideration which is energy efficient methods of cooling the data center. A good place to start is a floor plan that will allow for greater air flow through a data center.

   2.1 Hot Aisle/Cold Aisle Data Center Layout

   This particular layout requires servers to be set on a raised floor with perforated floor tiles. It is common for a server to be designed with the intake on the front of the unit. This design requires placing rows of cabinets so that the fronts or intakes faced each other thus creating the cold aisle. The cold aisle is also where perforated floor tiles are placed. By placing the exhaust end of the cabinets towards each other a hot aisle has been created. At the end of hot aisles, floor cooling units would be utilized to force cooler air back through the perforated floor thus reducing the amount of preheated air that is being introduced to the server.

   2.2 The Containment System

   The hot aisle/cold aisle design could be improved using containment curtains. The containment curtains allow for maximization of the cold aisle by containing the existing cool air and minimizing the amount of preheated air that enters the cold aisle. One example of a cold air containment system is the AirBlock[TM] containment systems. This containment system set up is noted as having the potential to save energy on air conditioning by as much as 15%. (http://www.dataclean.com/data-center-strip-curtains.html). For a successful hot aisle/cold aisle design it is essential to consider a front-to-back air flow pattern.

   2.3 Cable Management

   In conjunction with the hot aisle/cold aisle design, cable management is a second design consideration that may help reduce energy costs. According to the U.S Department of Energy (Best Practices Guide for Energy-Efficient Data Center Design, 2011) cable congestion in raised-floor plenums can sharply reduce the total airflow as well as degrade the airflow distribution through the perforated floor tiles. In addition to the issues with raised-floor plenums, it is important to realize that cables act as insulation. If left to hang loosely over the back of the rack the cables will essentially be trapping the hot air exhaust within the unit. This will require greater energy to cool the data center resulting in higher energy costs. Therefore, whenever possible cables should be routed through the hot aisle. The goal is to minimize the amount of obstructions that interfere with the cool air flow through the perforated floor tiles in the cold aisle.

   To facilitate this process, there are several cable containment...