When most people think about insulation, they think of staying warm during the winter. But insulation does more than just keep heat in when it's cold outside. It also helps keep your home comfortable during the summer months.
Insulation works by slowing the transfer of heat, helping keep unwanted heat out during the summer and conditioned air inside where it belongs. That means in the summer, it helps block hot outdoor air from entering, reducing strain on your cooling system and helping your home stay cooler.
To get the most out of your home's insulation this summer, here are a few things to keep in mind.
Signs Your Home May Need Better Insulation
Wondering if your insulation is doing its job? Watch for these common warning signs:
Hot or uneven temperatures throughout your home: If certain rooms are consistently warmer than others, or your upstairs feels like an oven during the summer, poor insulation could be to blame.
Your AC runs constantly: An air conditioner that seems to run nonstop yet still struggles to keep your home comfortable may be fighting a losing battle against heat entering through poorly insulated walls, ceilings, or the attic.
High energy bills: If your cooling costs are noticeably higher than those of similar-sized homes in your area, your insulation may not be doing its job.
Visible gaps or thin spots in insulation: In accessible areas such as the attic, signs of damaged, compressed, or insufficient insulation are often easy to spot. If you have batt insulation (precut insulation panels), check for the R-value printed on the material. In general, the higher the R-value, the greater the insulation's resistance to heat transfer.
Insulation vs. Air Sealing vs. Radiant Barriers vs. Ventilation: What's the Difference?
These four terms are often used interchangeably, but they address different problems:
Insulation slows heat transfer through walls, floors, ceilings, and attic spaces. It helps keep outdoor heat from moving into your home in the summer and indoor warmth from escaping in the winter.
Air sealing blocks air leaks: the gaps, cracks, and openings where hot outdoor air can sneak in and cool indoor air can escape. Air sealing and insulation work best when they're used together.
Radiant barriers help address a summer-specific problem: heat from the sun warming your roof and attic. Foil-backed materials or spray-on coatings, such as ARS's SolaShield™ radiant barrier, are applied to the underside of roof rafters to help reflect radiant heat before it can build up in your attic. This can block nearly 80% of radiant heat from entering your attic space.
Attic ventilation allows hot attic air to escape, helping reduce heat buildup that can otherwise make your home harder to cool. Proper attic ventilation works alongside insulation, not as a replacement for it.
The most effective approach combines all four. ARS's Energy Efficient Attic® system pairs insulation, ventilation, and a radiant barrier to potentially save 30% on heating and cooling bills.
Where Insulation Matters Most in Summer
Focus your attention on these high-impact areas:
Attic: The single most important area. Heat from the sun can build up in the attic, eventually making its way into your living spaces. Attic insulation and a radiant barrier here deliver the most noticeable results.
Ductwork: Leaky or uninsulated ducts running through hot attic spaces can lose a significant portion of your cooled air before it ever reaches a room. Ductwork inspection and sealing is worth prioritizing.
Crawl spaces: Heat and humidity from an unconditioned crawl space can migrate upward, making floors warm and increasing the load on your AC.
Garage-adjacent rooms: Rooms sharing a wall with an uninsulated garage are often noticeably hotter. Insulating that shared wall makes a real difference.
DIY vs. Professional Inspection: What You Can Do Yourself
Here are some DIY checks you can do today:
Visually inspect accessible attic insulation for thin spots, gaps, or damage.
Check for drafts around doors, windows, and electrical outlets.
Compare your energy bill against your neighbors' or previous years' usage.
Look at your AC's behavior: is it short-cycling or running all day?
When to call a professional: Some insulation work is best left to the pros. A professional can assess R-values throughout the home, identify hidden air leaks with proper equipment, recommend the right insulation type for your climate and home design, and balance ventilation needs with moisture control. ARS offers a free home energy audit, a good starting point before committing to any upgrades.
Schedule your AC maintenance at the same time as the audit to make sure your system isn't working harder than it needs to.
Frequently Asked Questions
How do I know if my home needs more insulation in the summer?
The most common signs are rooms that stay hot despite a running AC, an AC that won't cycle off, high cooling bills, and visible gaps or thin insulation in the attic.
What is the difference between insulation, air sealing, radiant barriers, and attic ventilation?
Insulation slows conductive and convective heat transfer. Air sealing stops air infiltration. Radiant barriers deflect solar radiation before it heats your attic. Ventilation exhausts hot air that builds up. All four work best together.
Should I add insulation myself or call a professional?
Basic visual checks and minor air sealing are reasonable DIY projects. For attic insulation installation, duct sealing, or a whole-home assessment, a professional will get better results and can identify issues you'd likely miss. Call ARS at 833.493.7669 or schedule a service online to get started.
For more summer home comfort tips, see the ARS Summer HVAC Energy Checklist, Benefits of Insulating Your Attic, How to Make Your Attic More Energy Efficient, and 10 Ways to Reduce Air Conditioning Costs. Learn more about ARS.
