Energy-Efficient Ways to Keep Your Home Cool This Summer

Set the thermostat a few degrees higher

Even a small bump up in the thermostat setting can make a big difference in cooling costs. Try setting it to 78°F when you’re home and awake and even warmer at night or when away. Each degree higher saves around 3% on cooling bills.

Key takeaways

Raise your thermostat to 78°F while home, as each degree higher saves approximately 3% on cooling costs.
Use cellular shades, reflective window films, and exterior landscaping to block solar heat before it enters your home.
Manage indoor humidity levels between 30% and 50% to improve comfort and reduce the workload on your air conditioner.
Seal air leaks around windows and doors, and ensure your attic is properly ventilated to prevent trapped heat buildup.
Switch to LED lighting and use smart power strips to eliminate unnecessary heat generated by electronics and appliances.

Use fans to feel cooler

Circulating fans help create a wind chill effect, making you feel cooler. Use ceiling fans on high in occupied rooms and table/floor fans to direct air flow in your direction.

Cook outside with a grill or air fryer

Using outdoor cooking appliances helps keep heat and humidity outside. Air fryers and electric pressure cookers also add less heat to your home than ovens.

Keep windows covered during the day

Closed blinds and curtains block sunlight from overheating your home’s interior. South-facing windows get the most sun exposure, so keep them covered on hot days.

Use appliances efficiently

Run appliances like washers, dryers and dishwashers at night when it’s cooler. Make sure AC filters are clean for optimal airflow. Let hot air escape by opening windows in the evening hours.

Harnessing Passive Cooling Through Nighttime Ventilation and Thermal Mass

While mechanical cooling is often the go-to, capitalizing on the natural drop in outdoor temperature overnight is a powerful, zero-cost strategy. Known as “night flushing,” this technique involves opening windows strategically after the sun sets to allow cool exterior air to displace the heat trapped inside. To maximize this, create a cross-ventilation path by opening windows on opposite sides of the house, preferably on the lower level and the highest point of the home to encourage the “stack effect,” where warm air rises and escapes through upper windows while cool air is pulled in from below.

Furthermore, consider your home’s thermal mass. Materials like concrete, stone, and tile absorb heat during the day and release it at night. If your home has significant thermal mass, it is crucial to keep windows closed during the early morning hours even if it feels cool outside, as opening them too early can allow the walls to absorb the rising solar heat. By controlling the intake of air based on the specific thermal properties of your construction materials, you can effectively “reset” your home’s temperature baseline every morning.

Strategic Landscaping for Natural Exterior Shading

The most effective way to keep a home cool is to stop the heat before it ever reaches your walls or windows. Strategic landscaping acts as a natural exterior shield. Deciduous trees planted on the south and west sides of your home provide a dual-benefit system: their broad leaves block intense summer solar radiation, while their seasonal cycle allows them to shed leaves in winter, welcoming the sun’s warmth when you need it most. If you lack space for large trees, consider installing trellises with climbing vines such as ivy or jasmine against west-facing exterior walls.

Beyond vegetation, hardscaping plays a vital role. Pavement and concrete driveways absorb vast amounts of solar energy, creating a micro-climate of heat that radiates toward your home. Planting ground cover or installing permeable pavers instead of solid asphalt can significantly lower the ambient temperature around your foundation. By reducing the intensity of the “heat island” effect immediately adjacent to your home, you lower the surface temperature of your exterior walls, which in turn reduces the heat gain transmitted to your interior living spaces.

Upgrading Window Treatments with Reflective and Insulating Technology

While standard blinds and curtains provide a basic barrier, they are often insufficient for modern energy efficiency standards. Cellular or “honeycomb” shades are superior because they create air pockets that act as a thermal buffer between the window glass and the room. For maximum impact, select shades with a white or reflective backing; these are designed to bounce solar radiation back through the window rather than absorbing it. In high-exposure areas, consider installing solar window film. These thin, nearly invisible layers are engineered to reject infrared light—the primary source of heat—while still allowing visible light to pass through, effectively turning your windows into heat-shielding portals.

Managing Indoor Humidity Levels to Enhance Cooling Efficiency

Humidity is often the silent culprit behind a home that feels warmer than the thermostat suggests. High moisture levels prevent sweat from evaporating from your skin, which is your body’s natural cooling mechanism. When your indoor humidity exceeds 60%, your air conditioner must work twice as hard to remove both the sensible heat and the latent heat (moisture) from the air. By utilizing a standalone dehumidifier in damp areas like basements or laundry rooms, you can maintain a relative humidity level between 30% and 50%.

This shift in humidity management often allows homeowners to feel perfectly comfortable at 78°F or even 80°F, whereas they might have felt sticky and overheated at 74°F with high humidity. Furthermore, ensure that all exhaust fans in bathrooms and kitchens are vented directly to the exterior of the home. Many builders incorrectly vent these into attic spaces, which traps moisture and heat within the building envelope, potentially leading to mold growth and increased cooling loads.

Insulation and Sealing: The Envelope Integrity Factor

Your cooling efforts are futile if your home is leaking air. Conduct a “candle test” around door frames, baseboards, and window seals to identify drafts. Even microscopic gaps allow cool, conditioned air to escape and hot, humid air to infiltrate. Use high-quality weatherstripping and silicone caulk to seal these gaps permanently. A common overlooked area is the attic hatch or pull-down stairs; these are often uninsulated, acting as a direct highway for heat to pour down into your home from the superheated attic space. Applying a foam gasket to the attic door and adding an insulation cover can lead to immediate, measurable reductions in cooling costs.

Additionally, assess your attic ventilation. If your soffit vents are blocked by insulation or debris, your attic becomes a furnace that transfers heat through your ceiling drywall into your living space. Ensuring your attic is properly ventilated—with active or passive vents—allows that trapped heat to escape before it can conduct into your home.

Optimizing Lighting and Electronics for Reduced Heat Loads

Every light bulb and electronic device in your home acts as a small space heater. While this is helpful in winter, it is counterproductive in summer. If you have not already made the switch to LED lighting, do so immediately; traditional incandescent bulbs convert roughly 90% of their energy into heat rather than light. By replacing these, you eliminate a constant source of internal heat gain.

Regarding electronics, many modern devices—especially gaming consoles, desktop computers, and large-screen televisions—generate significant thermal output even in standby mode. Use smart power strips to completely cut power to these devices when they are not in use. If you have a dedicated home office, consider moving the heat-generating hardware to a well-ventilated area away from where you sit, or ensure that your equipment is not positioned directly against a wall where heat can build up and transfer through the structure.

The Role of Reflective Roofing and Exterior Finishes

If you are planning home renovations, consider the long-term impact of your home’s exterior colors and materials. A dark-colored roof can reach temperatures 50°F to 60°F higher than a light-colored or reflective “cool roof” surface. These cool roof materials are designed to reflect more sunlight and absorb less heat. If a full roof replacement is not in the budget, consider painting exterior walls in lighter, high-reflectivity colors. Lighter colors reflect solar radiation, while darker colors absorb it, causing the exterior skin of your house to act as a heat-absorbing sponge throughout the day. By choosing materials and finishes that reject solar energy, you build a permanent, passive cooling advantage into the very structure of your home.

FAQ

What thermostat temperature saves the most money?

Setting your thermostat to 78°F while home and awake saves around 3% per degree higher vs. 72-74°F. Even warmer temperatures away from home and overnight save even more.