Fifteen Simple Ways to Green Your Data Center on the Cheap

Fifteen Simple Ways to Green Your Data Center on the Cheap

There's been a lot of talk lately about green data centers, and with good reason. As businesses move away from paper records and in-person transactions and more towards computer-based transactions and digital information storage, the amount of energy that data centers use is growing -- and fast.

According to the EPA, data center energy use doubled between 2000 and 2006, and many are worried this figure may double again in just a few years. With energy prices on the rise, smart IT and facility managers and even top executives are taking a look at ways to build and maintain not only effective, but efficient data centers.

The good news is that you don't have to spend big money to reap big energy savings. And while a few high-profile efforts have been launched recently that require significant capital outlays to be successful, there are a number of simple yet effective ways to "green" a data center, techniques that are kind to budgets and easy to implement.

Some simple ideas work best with new facilities, while others are better suited to retrofits of existing data centers, but the truth is, all will work well to cut energy use, and yield financial savings, while not compromising reliability.

If your company is planning to build a new data center -- and many companies are -- it pays to build energy efficiency into your plans. Here are eight fairly easy ideas and technologies for new data centers that you should think about:

1. Air-side economizers not just for the office anymore. A bit like opening a window on a cool day, an air-side economizer takes advantage of cooler outside air to cool the inside of your data center. At the very least, they require much less energy than typical HVAC systems, and often provide free cooling. In the past, data centers avoided the use of air-side economizers because of a belief in the need to maintain tight humidity and temperature controls. The technology has traditionally been very common in many office settings, but today companies like Intel prove that servers are much more durable than previously believed. As a result, air-side economizers are installed more often. The best news? Paybacks can be enormous. A company's data center could see as much as a 60 or 70 percent reduction in cooling bills compared to those of typical data centers.

2. Centralize your air handling. One simple solution for energy savings is to place your HVAC equipment and your economizers on the roof, or in a separate room on an exterior wall, rather than inside your building. When your equipment is outside the space, it's easier to reach and maintain than when it's inside, and it runs much more efficiently.

3. Practice good airflow management. Almost everyone knows that servers require cool air at the front and discharge heated air at the back. And yet ensuring that hot and cold air don't mix in the wrong places still isn't top of mind when designing data centers or deploying servers into the room. Ensuring that cool air goes where you need it (and that hot air doesn't) is as simple as installing "blanking panels" within server cabinets to block the short-circuiting of hot air. You should also put servers back-to-back and front-to-front in a "hot and cold aisle" arrangement. You can even install hot aisle barriers (hot aisle containment) -- similar to the plastic sheeting you see in supermarket cold cases -- to contain heat at the end of the hot rows and above the cabinets.

4. Roll with a heat wheel. A heat wheel is a type of heat exchanger designed as a big aluminum wheel that both absorbs heat and transfers it from the inside to the outside without introducing outside air into the facility. This provides the same kind of cooling as an air-side economizer, but without the addition of outside air.

5. Change your supply air temperature. Most data centers run at temperatures much cooler than necessary. While typical operating temperatures are usually about 56 to 60 degrees Fahrenheit, recent tests by Intel, Sun Microsystems and NetApp have shown that servers can tolerate much higher temperatures as well as higher humidity. If you are using good airflow management in your data center, you can stop worrying about keeping the air conditioned to 56 degrees, and start saving energy and money.

6. Build what you need. Building a modular and scalable infrastructure based upon a logical and consistent power and cooling module will allow the facility to purchase only what is required for its initial computing needs while allowing seamless upgrades and additions as more computing power or space are needed.

7. Monitor, monitor, monitor. Monitor critical load and mechanical power, water consumption, gas consumption, and even waste water. Direct Digital Control (DDC) systems are becoming more common and have the innate ability to monitor and trend anything. As a result, it is simple today to see what is going on within the facility and project usage into the future. In addition, it provides more immediate feedback on implementation of energy saving measures or operational changes.

8. Ask: What is my carbon footprint? Nearly all pundits agree there will be some form of carbon regulation in the future. Knowing your carbon footprint will allow the data center manager or CIO to make informed decisions on data center operations and usage looking toward the future.

If you are in charge of an existing data center and looking for simple ways to start saving energy and money without a major remodel, we recommend a few ideas to get you started:

1. Keep the hot and cold air separate. Data center servers generate heat but need cool air to run well. Yet it's surprising how few data center managers have thought about keeping the hot air separate from the cold air. Many facilities are still designed so that the hot air from the back of a server is blowing into the front of another server. This creates a need for brute force air conditioning throughout the data center and often supplemental fans sitting on the floor, which both use massive amounts of energy very inefficiently. By configuring servers to prevent hot and cold air from mixing -- either through the use of hot and cold aisle barriers or by placing servers back- to-back and front-to-front throughout the data center -- the amount of cool air drops dramatically throughout the facility.

2. Airflow management is key. Again, rather than worrying about overall temperatures in a data center, the key to running one efficiently is to think about the microclimates created by servers throughout. Considering how air flows and is heated by servers allows you to see where to implement low-cost solutions. For example, blanking panels in server cabinets to stop hot air from short-circuiting through the cabinet, or "hot and cold aisle barriers," which are essentially plastic sheets hung from above that reduce the mixing of hot and cold air. Another option: On a raised-floor computer room cooling unit ,you can install return-air duct extensions that direct the warmer air out through the ceiling. This is a fairly simple change that will generate great energy savings payback and reduce hot spots.

3. Manage energy in addition to reliability and uptime. Data center managers have traditionally monitored only server reliability and consistency. Yet in today's high-energy business environment, you don't have to sacrifice energy savings for reliability. Many local utilities offer incentive programs, in essence paying business customers for energy saved. For example, California utility PG & E pays its large customers 14 cents per kilowatt hour saved.

4. Make sure equipment is running correctly. It's common to find separate data center cooling units set so that one humidifier is providing moist air while the other is dehumidifying, causing both to work harder than they should. The solution? Check temperature and humidity controls on HVAC equipment regularly to ensure that all are working properly and efficiently.

5. If you aren't using it, turn it off. Idle servers often are kept running even if they are not used. Just like your lights at home, turning idle servers off is easy and provides an immediate energy and cost savings. Similarly for cooling units, if the extra capacity isn't needed, then consider turning the unit off.

6. Install VFDs on computer room cooling units. Chilled water units typically can be operated at lower air flows because there is spare capacity. The fan energy savings can be enormous with variable speed drives (VFD) operating at partial speed. This goes very well with improved air flow management solutions.

7. It's a virtual world. Grid computing using current server hardware or blade server technology provides a tremendous opportunity to "tune" the computing environment to the computing requirement and as a result can reduce the power consumption for servers and air conditioners.

Finally, whether you are building a new data center or trying to 'green' an existing one, there are a few overall management changes to keep in mind if you really want to reduce energy use. First, set targets for energy use company-wide and allocate operating costs based on those targets. By making internal departments aware of energy use -- and by sharing targets and actual usage figures with the entire company -- you make saving energy part of the corporate mindset from top to bottom.

Second, bridge the disconnect between IT and the facilities department. In most companies, these two departments don't talk much and they certainly don't jointly plan how to save energy. They should.

Most importantly, recognize that energy is an increasingly expensive part of running your business. And, it's one of the few costs you can control just by managing energy use efficiently. Once you recognize that actively managing energy is as important as any other key business function, you are on your way to a healthier bottom line.
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