You might have noticed that certain rooms remain stubbornly warm despite the air conditioner running all day. It’s a frustrating problem; your energy bills climb, yet the comfort you expect never quite arrives. In many cases, the issue isn’t your AC at all, but the hidden air leaks and inadequate insulation that let hot air seep in while cooled air escapes.
That’s why improving your home’s insulation is often the key to real, lasting relief. Among the most effective options, spray foam insulation stands out for its ability to seal every gap and create a continuous thermal barrier. More than just a seasonal fix, it’s an investment that ensures year-round efficiency, making your home cooler in the summer and warmer in the winter.
In this blog, we’ll explore how spray foam insulation works during hot months, its key benefits, and expert tips for maximising your home’s cooling efficiency.
How Spray Foam Insulation works in summer
A skilled spray foam contractor applies the foam, which begins as a liquid that rapidly expands into a dense, insulating material, filling the cracks and crevices to form a continuous and rigid barrier. It is available in two main types: open-cell, which expands more and offers excellent insulation with added sound dampening, and the other one is closed-cell, which is denser and also resists moisture, and even reinforces structural integrity.
Once applied, it disrupts all three modes of heat transfer: conductive through materials like studs or drywall, and the convective heat that is carried by air leaks. By sealing every gap and creating an airtight envelope, spray foam keeps heat out and cool air in.
Key benefits of Spray Foam Insulation during hot weather
Airtight Thermal Barrier
One of the most important advantages of spray foam insulation is its ability to create a true airtight seal. By closing gaps around ducts, attic hatches, and plumbing chases, it stops hot, humid air from entering and prevents conditioned air from escaping. This airtight barrier is the foundation for all other cooling benefits. Even many reputable spray insulation companies note that this allows your air conditioner to run for shorter periods while still maintaining steady indoor temperatures.
High R‑Value per Inch
Compared to fibreglass or cellulose, closed‑cell foam delivers superior thermal resistance within compact spaces, giving more cooling power even in thin layers.
Improved HVAC Efficiency & Lower Energy Bills
It helps to reduce the heat gain and leaks, thus the cooling system faces less strain. Many homeowners also observe energy savings between 20–40% during peak summer months.
Moisture & Humidity Control
It is very beneficial in humid climates, as closed‑cell foam doubles as a vapour barrier. That helps to reduce condensation, mold growth, and the damp air, which can undermine both comfort and indoor air quality.
Consistent Comfort & Fewer Hot Spots
Spray foam creates uniform insulation in the house and eliminates temperature swings between upstairs bedrooms and living areas. This results in fewer complaints about rooms that feel hot, even while others stay cool.
Durability & Longevity
Once cured, spray foam forms a solid, stable structure that won’t sag, compress, or settle over time. Unlike older materials that degrade over time, foam delivers cool efficiency year after year.
Best areas in your home to apply Spray Foam
Crawl Spaces and Rim Joists
Uninsulated crawl spaces act like heat traps. Spray foam in rim joists seals these gaps, preventing hot air from entering and conditioned air from escaping downward.
Exterior Walls & Around Ductwork
You can apply spray foam over walls that often contain voids or unsealed penetrations. The foam fills these gaps, stops air infiltration, and helps ducts maintain their efficiency, especially in homes where ductwork runs through unconditioned areas.
Garages, Sun Rooms & Additions
Spaces not initially designed for insulation, such as garages or sunrooms, can benefit hugely from foam retrofits offered by most reputable foam insulation companies, making them comfortable and usable during hot days.
Expert Tips for Maximising Cooling Efficiency
Choose the Right Foam Type for Your Climate
In humid regions, closed‑cell spray foam is ideal. In drier climates or for sound‑control needs, open‑cell may suffice while keeping budgets lower.
Ensure Professional Installation
Make sure to hire a professional insulation contractor for the installation process, as their expertise will help in correctly applying the required spray patterns, thickness, and curing needs.
Inspect for Proper Coverage in Hard‑to‑Reach Areas
Rim joists, knee walls, and vaulted ceilings often receive spotty coverage. Always confirm that the installer has addressed these zones for complete envelope integrity.
Follow Up with Energy Audits
Use blower‑door testing or infrared scans post‑installation to verify air tightness and locate any remaining leaks. These measures fine‑tune the foam’s effectiveness.
Conclusion
Investing in spray foam insulation is a game-changer technique to keep your home comfortable during extreme summer heat. Sealing hidden gaps and forming an unbroken thermal shield, it helps your cooling system work more efficiently. This lasting improvement means you can enjoy stable indoor temperatures and consistent comfort year after year.
At May Energy Solutions, we specialise in helping homeowners achieve these results through expert spray foam installation. If you’re ready to create a cooler, more energy-efficient home, contact us today at may@mayenergysolutions.com and start experiencing the benefits.