Spray foam insulation is revolutionizing the insulation and energy efficiency industries, known for its ability to significantly reduce energy consumption—sometimes by as much as 70%. But how much can it truly save when used in a real-world scenario? This case study explores the impact of retrofitting a home with spray foam insulation.

Spray foam insulation is a high-performance insulating material that expands upon application, sealing gaps, cracks, and air leaks more effectively than traditional insulation materials like fiberglass or cellulose. It comes in two main types: open-cell and closed-cell, both of which provide superior thermal resistance and air-sealing properties. When used in an attic retrofit, the process involves removing old insulation and applying spray foam directly to the underside of the roof decking, creating a more airtight and energy-efficient home.

Why Do Spray Foam Manufacturers Claim 70% Energy Reduction? 

Spray foam manufacturers often claim energy reduction of up to 70% but these numbers are based on ideal conditions that may not apply to every home. Let's break down some of the factors. 

1. Mild Climate Conditions- Some studies showing extreme energy savings are conducted in regions with milder climates, where insulation upgrades have a more noticeable impact on heating and cooling costs.
2. Optimized HVAC System – Many manufacturers assume homeowners will downsize or replace their HVAC system after installing spray foam, leading to further energy savings that aren’t directly from the insulation itself.
3. Controlled Testing Environments – From laboratory settings rather than real-world conditions, where factors like air leakage from doors and windows, occupant behavior, and regional climate aren’t accounted for.
4. New construction vs. Retrofitting - One key factor in the 70% energy reduction claim is that manufacturers often base their data on new construction homes. In these cases, the initial energy measurements come from a home with no insulation at all, making the improvement seem dramatic once spray foam is added. However, in retrofit projects, existing insulation—though inefficient—still provides some resistance to energy loss. Since the starting point isn’t a completely uninsulated space, the actual energy savings from switching to spray foam are typically lower than those seen in new construction studies.

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The Question Remains: What Will Spray Foam Save Me on My Energy Usage?

In a 2022 case study conducted in Keller, Texas, by Superior Attic, LLC, it was determined that retrofitting an attic with spray foam insulation could lead to a conservative 45.5% reduction in overall energy usage. Here’s a breakdown of the project and its results. (All supporting documents will be sourced below.)

The Case Study: Before and After Spray Foam

On September 15, 2022, the homeowners in Keller, Texas, reached out to Superior Attic due to high energy bills and inconsistent heating and cooling throughout their home. Upon inspection, the attic was found to have 8”-10” of cellulose insulation. That same month, the home’s energy usage was 1,173 kWh, with an average outdoor temperature of 84°F.

On October 12, 2022, our team began the retrofit process, which took just one day to complete. The existing insulation was removed, the attic was sanitized, and 5.5” of AccuFoam Open Cell Spray Foam was applied to the underside of the roof decking. That month, despite only having spray foam insulation for half the billing cycle, the home’s energy usage dropped to 533 kWh—a noticeable improvement with the same 84°F average temperature.

The savings continued in the following months:

• November 2022: Energy usage dropped to 302 kWh as temperatures cooled to an average of 73°F.
• December 2022: Despite a cold snap bringing average temperatures down to 28°F, the home used only 280 kWh, demonstrating spray foam’s ability to regulate indoor temperatures even in extreme conditions.

Home Specifications

• Square Footage: 1,425 sq. ft.
• Year Built: 2006
• Location: Keller, Texas
• Number of Occupants: 3
• Work-from-Home Occupants: 2
• Average Thermostat Setting: 69°F
• Exterior Wall Insulation: R-13 Batts

(All supporting documents will be sourced below.)

Conclusion

Spray foam insulation is a game-changer in the energy efficiency industry. While some manufacturers claim savings of up to 70%, real-world data suggests a reliable 45.5% reduction in energy usage for residential retrofits. In the Keller case study, these savings translated into a four-year return on investment, alongside improved comfort and control over the home’s heating and cooling.

For homeowners looking to cut energy costs, enhance comfort, and improve efficiency, spray foam insulation is a proven solution with long-term benefits.

(All supporting documents will be sourced below.)

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