Two articles in Buildings offer ways to keep commercial buildings comfortable this summer, and save money at the same time.

Spring is a great time to make sure a building's cooling systems are economically and environmentally responsible. Efficiency is as important as comfort. Most air conditioning maintenance and repairs were done during winter, but systems should be tested before the heat of summer is upon us.

"With a little preparation this spring, you can ensure that your facility will make a smooth and efficient transition into the summer," wrote John Conover in his March 2007 conttributed article, "Prepare for a High-Performing, Efficient Cooling Season" in Buildings Magazine.

One significant burden on cooling systems isn't part of the equipment and doesn't show up in system tests. The building envelope -- the exterior walls, windows, doors and roof -- affects efficiency when air leaks allow warm air in and let conditioned air escape.

"Control Air Leakage, Save Energy" by Anne Goedken offers advice for stopping unwanted infiltration. Older buildings are the worst culprits for infiltration, although their operable windows are said to improve indoor air quality, or IAQ.

"Infiltration can also decrease the quality of your building's IAQ. And, numerous studies have shown that even the newest high-performance buildings leak and let air in," wrote Goedken. For those who really want to learn the ins and outs of infiltration, the article cites two comprehensive studies:

• A 48-page report from 2005 by the U.S. Department of Energy’s Office of Building Technologies, "Investigation of the Impact of the Impact of Commercial Building Envelope Airtightness on HVAC Energy Use"
• A 2005 study, "Impact of Infiltration on Heating and Cooling Loads in US Office Buildings," also sponsored by the U.S. DOE Office of Building Technologies