Summer is here, prompting homeowners to crank up their air conditioners, but that can bump up electricity bills and strain the environment. Here are some eco-friendly tips to stay cool at home with minimal or zero use of the AC.

During daylight hours when outside temperatures are highest, close all windows to seal out the  humidity and heat. Open them at night to expel hot air and welcome the night’s fresh breezes. To speed up ventilation, place a window fan on the east side of the house blowing in to pull in cooler night air, and another window fan on the west side blowing out to expel warm air.

Ceiling fans are great, but technically, they cool people, not the house, so there’s no need to run them in empty rooms. Set the rotation counterclockwise to push air down and at the fastest setting for maximum relief. Fan blades collect dust; regular wiping is recommended to maintain good air quality. Blade size and angles matter—choose those big enough for the room, set at 12-to-15-degree angles.

White reflects heat and black absorbs it. Paint the roof white or another light shade and insulate attic floors to keep from transferring heat into living spaces. The sun’s effect intensifies as it radiates through windows. Shutters, awnings and external blinds will keep unwanted heat outside, as can strategically placed trees and shrubs that shade east- and west-facing windows. Reflective or sun-control film on windows reduces solar heat and keeps out ultraviolet rays. Close curtains (preferably with white backs) in any room that gets direct sunlight.

Replace heat-generating items around the house with cooler alternatives. Choose eco-friendly LED lights instead of traditional, hot-to-the-touch lightbulbs. Hang-dry clothes in the sun rather than running the dryer. Grab the slow-cooker, Instant Pot or outdoor barbecue and give the oven a break. Ditch the dishwasher’s heated drying option; choose the air-dry cycle instead.

On a scorching day, the air conditioner may be the only option. Replace an old unit with a newer, high-efficiency model and invest in a smart thermostat that can be programmed based on daily schedules and weather conditions. Dirty filters use much more energy than clean ones, so replace or clean them regularly.