ABOUT COOLING Consider living without air conditioning For thousands of years, people have lived in hot climates without air conditioning. Because air conditioners use lots of energy, green builders should consider other cooling options before concluding that a house requires air conditioning. According to the U.S. Department of Energy, two-thirds of U.S. homes have air conditioning systems, which collectively consume 5% of all electricity generated in the country and cost homeowners about $11 billion a year. In parts of the country where high temperatures, high humidity or both are a fact of life, air conditioning is considered a necessity. There are, however, a number of ways to lower indoor air temperatures short of installing large, energy-intensive air conditioning systems. Among suggestions from the American Council for an Energy-Efficient Economy: Insulate and tighten. Well-insulated houses don’t need as much mechanical air conditioning as poorly insulated houses. Meeting or exceeding insulation levels recommended by the Department of Energy is a good first step. That’s easiest to do in new construction but still feasible as a retrofit, especially when it comes to attic insulation. Choose low-solar-gain glazing. Windows with low solar heat gain coefficients will help lower indoor temperatures and significantly reduce cooling loads. Replace inefficient appliances and products. Replacing old refrigerators with energy-efficient models, exchanging incandescent light bulbs with fluorescents and unplugging electronic equipment when not in use to reduce phantom energy loads all contribute to a cooler interior. Use cool exterior finishes. Light colored roofing and siding can reduce cooling demands by as much as 15%. Keep it shady. Planting deciduous trees and shrubs near south- and west-facing walls can help block intense summer sun. Window shades and horizontal trellises are an option where outdoor plantings are not practical or ineffective. Update existing cooling equipment. If the house already has an…