Why Air Sealing Matters More Than R-Value in Commercial Buildings
- NFW Author
- Jun 10
- 2 min read
When evaluating insulation, most people focus on R-value, which measures resistance to heat flow; it does not tell the full story of how the full building structure performs. In commercial construction, air leakage often has a greater impact on efficiency than insulation levels alone.
For full air sealing, NFW recommends spray foam insulation and roof coatings.
What R-Value Actually Measures
R-value indicates how well a material resists heat transfer through conduction. Higher R-values mean better insulation performance on paper.
However, R-value assumes ideal conditions. It does not account for air movement, installation gaps or real-world building conditions. If air is moving freely through or around insulation, the effective performance drops significantly.
This is why buildings with high R-value insulation can still experience heat loss, drafts and inconsistent temperatures.
The Hidden Impact of Air Leakage
Air leakage occurs when outside air enters the building and conditioned air escapes. This happens through small gaps, cracks and joints in the building envelope. Uncontrolled air leakage can account for a significant portion of energy loss in buildings.
In commercial spaces, this leads to:
Increased heating and cooling costs
Uneven indoor temperatures
Greater strain on HVAC systems
Moisture movement within walls and ceilings
Even small openings can have a large cumulative effect across a building.
Why Air Movement Reduces Insulation Performance
Insulation is designed to slow heat transfer, but it cannot stop moving air. When air passes through or around insulation, it carries heat with it. This process, known as convective heat transfer, bypasses the insulation entirely. As a result, the effective R-value drops, sometimes dramatically. In other words, a building with perfect air sealing and moderate insulation often performs better than one with high R-value insulation and poor air control.
How Spray Foam Solves Both Problems
Spray foam stands out because it addresses both insulation and air sealing at the same time. When applied, it expands to fill gaps and adhere to surfaces, creating a continuous barrier that also insulates to prevent thermal transfer.
Focusing only on R-value can lead to underperforming buildings. A more effective approach is to prioritize air sealing first, then ensure adequate insulation levels.
This combination delivers:
Better energy efficiency
Improved indoor comfort
Reduced moisture-related issues
Longer-lasting building performance
Increase Air Sealing Through Spray Foam Insulation
For commercial properties, this translates directly into lower operating costs and fewer maintenance issues. At NFW, we design insulation systems that perform in real conditions, all year long – from –40C to +35C.
Contact our experienced team of spray foam insulation contractors in Red Deer and Central Alberta for your commercial roof insulation and coating projects:
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