Seven no-AC strategies to keep homes cool in summer heat

As summer heat intensifies, many homes worldwide, including parts of Europe and older U.S. housing, lack central air conditioning. Even where AC exists, continuous use strains grids and raises bills. Effective cooling without mechanical refrigeration relies on physics: blocking solar heat, deliberate airflow, and shifting habits. Key strategies include closing blinds before sun hits windows—light-colored or reflective coverings can cut heat gain by up to 45%—and using cross-ventilation by opening windows on opposite sides after sunset. Ceiling fans set counterclockwise create a wind-chill effect, allowing thermostat increases of about 4°F. Moving heat-generating tasks like cooking and laundry to cooler times reduces internal heat. Whole-house fans and attic fans expel hot air, with attic fans reducing stored heat. Exterior shading, such as awnings and trees, is more effective than indoor coverings. Dehumidifiers lower perceived temperature, and sealing air leaks and adding insulation prevent heat entry. These methods are grounded in building physics and can be combined for greater effect, though they don't replace AC for vulnerable individuals.