How to keep your home cool in the summer heat

Key takeaways

• Upgrading insulation, window treatments and exterior shade are practical ways to keep your home cool in the summer and lower energy costs.
• Regular HVAC maintenance, including filter changes and professional tune-ups, helps keep cooling efficient and prevents costly repairs during heat waves.
• Buyers should look for cooling upgrades like Energy Star windows, smart thermostats and mature shade trees to ensure comfort and add value to a home.

Keeping your home cool during summer is about more than turning on the air conditioner.

A combination of smart upgrades, regular maintenance and strategic choices can lower your energy bills and improve comfort during summer heat waves.

"Summer heat puts real stress on a home," said Jon Hill, owner of The Energists, a home energy consulting firm in Houston, Texas. "The ones that handle it best are the ones where someone took the time to address the basics: insulation, airflow and shade."

Window treatments are one of the simplest ways to reduce indoor heat. Blackout curtains, cellular shades and reflective window films block sunlight before it warms your living spaces. South- and west-facing windows receive the most direct sun and benefit the most from these treatments.

• Thermal curtains create an insulating barrier between the window glass and the room.
• Cellular shades trap air in honeycomb-shaped pockets, which slows heat transfer.
• Reflective films applied directly to the glass can reduce solar heat gain without blocking your view entirely.

Insulation slows heat transfer, keeping cool air inside and hot air out. Attics and exterior walls are the most important areas to check, especially in older homes where insulation may be thin or missing.

"The attic is often the biggest source of heat entering the home, but it's also one of the last places homeowners think to look," Hill said.

The attic could be leaking the cool air your heating, ventilation and air conditioning (HVAC) is generating. Upgrading insulation can reduce cooling costs and help your HVAC system work more efficiently.

"Even a high-efficiency HVAC system must work harder when conditioned air escapes through gaps in the building envelope, the outer walls, roof and foundation, or when excessive heat enters through the attic," said David Rames, senior specialist of product promotion and development at Midea Residential Air Conditioning based in Louisville, Kentucky.

If your home has a gap, it's like having cool air escaping from a refrigerator door that's partially open. The refrigerator needs to work harder to keep the food cold, which burns more energy.

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Regular maintenance keeps your cooling system running efficiently and prevents problems during the hottest months. Here are the steps that matter most:

• Change your air filter every 30 to 90 days, depending on filter type, household size and pets. A dirty filter restricts airflow, forcing the system to work harder. For more guidance, see the EPA's guide to air filters in the home.
• Schedule a professional tune-up before peak season to catch issues early.
• Check that all vents are open and unblocked to maintain balanced airflow throughout your home.
• Use a smart thermostat to automate cooling schedules and reduce energy waste.
• Avoid setting the thermostat very low, thinking it will cool the house faster.

Rames said the most effective strategy is to ensure your HVAC system operates as efficiently as possible before and during a heat wave. "A clean air filter, unobstructed vents and regular preventive maintenance help the system move air efficiently and avoid unnecessary energy consumption," Rames said. Many cooling complaints during heat waves are actually due to restricted airflow or deferred maintenance rather than equipment limitations.
"A thermostat isn't a gas pedal. Setting it to 65 doesn't make the AC cool faster than setting it to 75. It just tells the system when to stop," Hill said.

Landscaping with trees, shrubs and awnings blocks sunlight and reduces the amount of heat that enters your home. Mature shade trees on the south and west sides of a property are the most effective because they block direct sun during the hottest parts of the day.

"People tend to focus on making the AC work harder when they should be focusing on making the house absorb less heat," Hill said.

Reducing the heat your home absorbs is often more effective than relying solely on your cooling system. Awnings over windows and strategic planting can make a measurable difference in indoor temperatures.

Where you live can play a role in keeping your home cool. Neighborhoods with more tree coverage will be cooler than homes with limited shade.

The best way to keep your home cool in summer depends on where you live. Each region presents different challenges, and the right cooling strategy varies accordingly.

• Southeast (humid climates): Dehumidification is just as important as lowering the temperature. Prioritize a right-sized HVAC system that runs long enough to remove moisture, and ensure ductwork is sealed to prevent condensation.
• Southwest (dry climates): Evaporative coolers can be a good alternative to traditional air conditioning. Reflective window films and exterior shade are especially effective where intense sun is the primary heat source.
• Midwest (mixed climates): A balanced approach works best. Combine upgraded insulation, ceiling fans and a properly sized HVAC system to handle both hot, humid stretches and dry heat.
• Northeast (variable summers): Focus on insulation and air sealing to get the most from your cooling system during shorter but intense heat waves. Window treatments on south- and west-facing windows make a big difference.
• Pacific Northwest (mild but warming): Many older homes lack central air conditioning. Portable or ductless mini-split systems, combined with ceiling fans and blackout curtains, can handle increasingly warm summers without a full HVAC overhaul.

"In humid climates like New Orleans, it's not just about getting the temperature down. If your system is oversized, it'll cool the air fast but won't run long enough to pull the moisture out," said Patrick Gambel, managing partner of General Heating & Air Conditioning in New Orleans.

Right-sizing your HVAC system matters in every climate. A system that is too large will short-cycle, shutting off prematurely, leaving humidity high and wasting energy. A system that is too small will run constantly without reaching a comfortable temperature. Matching the system to your home and climate gives you the best results.

Knowing how your system behaves during extreme heat helps you keep your home cool all summer. During a heat wave, it is normal for your HVAC system to run longer than usual.

"Most systems are designed around typical summer conditions, not record-breaking temperatures every day for weeks," Hill said.

Continuous operation alone does not always indicate a problem.

"During an extreme heat wave, it's totally normal for your AC system to run longer than it normally does," Gambel said.

If you notice any of these issues, your system may need professional inspection:

• Weak airflow from supply vents
• Warm air coming through the vents
• Rising indoor temperatures that won't come down
• Ice on refrigerant lines or the system itself
• Unusual noises during operation
• Higher humidity levels inside the home

Regular maintenance and prompt attention to these signs can keep your home comfortable and prevent costly repairs.

These features determine how well a home stays cool during summer. When shopping for a home, prioritize cooling upgrades that make a real difference in comfort:

• Energy Star windows that block heat and reduce energy costs
• Upgraded insulation in attics and exterior walls to keep cool air inside
• Smart thermostats for efficient temperature control and lower cooling bills
• Mature shade trees on the south and west sides to block direct sunlight
• A well-maintained HVAC system with a documented service history

Before making an offer, ask about insulation ratings, the age and condition of the HVAC system, and the efficiency of the windows. To find listings with these features, search for homes on Homes.com and filter for cooling upgrades.

Upgrades that keep a home cool in summer can add resale value. Variable-speed heat pump systems offer the greatest long-term energy savings because they adjust output to match the home's actual cooling demand. Unlike single-stage equipment, these systems operate more efficiently and maintain steady temperatures.

"Variable-speed heat pump systems offer some of the greatest long-term opportunities for reducing cooling energy consumption while improving comfort," Rames said. "Unlike traditional single-stage equipment that cycles on and off at full capacity, variable-speed systems continuously adjust output to match the home's actual cooling demand."

Looking at the whole house is important. Upgrades like insulation, duct sealing, smart thermostats and efficient HVAC work together to lower cooling costs. Homes that stay comfortable during heat waves tend to have the lowest cooling bills and attract more buyers.

"Comfort and efficiency usually go hand in hand. The homes that stay comfortable during a heat wave are often the same homes with the lowest cooling costs," Hill said.

• Change AC filters regularly
• Schedule an HVAC tune-up before peak season
• Install or upgrade window treatments to block heat
• Check attic insulation for gaps or low coverage
• Use ceiling fans to circulate air
• Program your smart thermostat for efficient cooling
• Add exterior shade with trees or awnings
• Seal air leaks around windows and doors
• Keep vents open and unblocked
• Monitor for warning signs during heat waves

Small steps like these help keep your home comfortable and lower your energy costs all summer.

The most energy-efficient approach combines upgraded insulation, ceiling fans, smart thermostats and a high-efficiency HVAC system. No single fix works best alone. A whole-house strategy keeps cool air inside, reduces energy use and maintains comfort during hot weather.

Closing vents can increase pressure in your duct system and reduce efficiency. It may cause your HVAC system to work harder, leading to higher energy costs and possible damage. Leave vents open to maintain balanced airflow throughout the home.

It's normal for your system to run longer than usual during extreme heat. However, weak airflow, warm air from vents, rising indoor temperatures, ice on refrigerant lines, or unusual noises are signs that your system may need a professional inspection.