What Are Some Ways to Keep My House Naturally Cool During Hot Weather?

Blasting the AC may feel great during heat waves, but it’s neither financially nor environmentally friendly. Passive cooling techniques, which incorporate building design and materials to regulate heat, require a bit of forethought but can dramatically reduce interior temperatures with little cost to you or Planet Earth, notes University of Oregon assistant professor of environmental design Alexandra Rempel, MArch, PhD, in a 2022 report published in Applied Energy.

1. Shade strategically. Light-­colored cellular shades block heat and light more effectively than curtains do, especially when installed along tracks on the sides of window frames. Pull down the shades when sunlight hits the window — even before the day heats up — but let your windows “breathe” at night, advises Rempel. This allows the glass to radiate trapped heat outward.
2. Enhance ventilation. Well-controlled shading and ventilation can reduce air-conditioning loads by up to 70 percent in some climates and seasons, Rempel’s team notes. Opening multiple windows creates cooling cross-drafts, but only when it’s cooler outside. Close the windows as temperatures rise and let a box fan take over: It can circulate the cool air you’ve already introduced into the house with minimal energy use. If you have rooms you don’t use during the day, shut their doors — then vent the warm air out at night.
3. Cross-ventilate at night. Draw cool night air through your house by opening windows, and pull warm air outside by placing a box fan in one window as an exhaust.
4. Limit your use of appliances and electronics. Many of our most-used appliances and electronics — dishwashers, ovens, refrigerators, overhead lighting, computers, televisions, and gaming systems — generate heat while running. Limit your use when possible: Wash dishes by hand, rely on natural light during the day, and opt for meals that don’t require heating (if need be, choose the microwave instead of the stove). Minimize how often you open the refrigerator door and watch TV only in the evenings, when temperatures drop.
5. Landscape for shade. Shade-bearing trees and shrubs planted on the west and southwest sides of your house can help keep heat and sunlight at bay. “The shade of a large tree can reduce the temperature up to 10 degrees, and these effects can be felt inside a house as well,” says Lynn Steiner, author of Grow Native. “Studies show that a few well-placed shade trees can reduce cooling costs by as much as 35 percent.” (For more tree-planting advice from Steiner, see “How to Plant a Tree.”)

This was excerpted from “14 Tips to Stay Cool During the Summer” which was published in Experience Life.