After taking some lumps by situating its first ever data center in a primarily coal-powered region, Facebook is now making a concerted effort to become synonymous with Green IT.

With its newly launched Green on Facebook page, the social networking company is spotlighting relevant articles from around the web and pulling back the curtain a little on its own sustainability efforts. On its info page, Facebook features its foray into green code,  HipHop for PHP, which is already lowering CPU consumption (by up to 50 percent) for the company and is set to do the same for others. There’s also Haystack, which improves storage infrastructure efficiency by using a different approach to photo storage — important because folks upload 220 million new photos a week, or about 25TB worth of storage.

For those interested in its data center operations, Facebook Engineering detailed some of the strategies that are helping the company save big on cooling costs. Here’s their approach to free-cooling one of the company’s facilities:

Outside air is always the cheapest cooling solution, and we realized large gains from lowering the electricity usage by expanding the time window for air-side economization — using outside air to cool the data center. This minimizes the energy required to mechanically cool the air down to the design temperature. When the supply temperature set point was 51 degrees, free cooling was achieved for only 2,200 hours during the year. In this situation, the DX system must work to cool the air to 51 degrees for the remaining 6,560 hours in the year. By raising the supply temperature set point to 67 degrees Fahrenheit, we could now use outside air for 6,800 hours per year, more than tripling our free cooling hours. The DX cooling system now runs for a much a shorter time period, reducing the demand by 260 kW.

Is it enough to make us forget about selecting Prineville for its “green” data center? Nope. But it’s a step — a small step, mind you — in the right direction.