Real Performance

R-value is the most common method of labeling the thermal performance of an insulation product. However, labeled R-value often does not reflect how well an insulation system will perform in the real world.


The R-value assigned to insulation products is measured under laboratory conditions that do not necessarily reflect real-world environmental conditions or installation quality. R-value measurements are derived from small, meticulously prepared laboratory samples that are tested in an airtight hot box without an air pressure differential across the test sample. In reality, building envelopes are constantly exposed to differential air pressures and temperature swings and insulation is often carelessly installed with numerous defects and bypasses.


Extremely air permeable insulation systems, such as low density fiberglass, can be especially prone to R-value degradation and additional heat loss/gain under adverse installation and climate conditions. Low density fiberglass is a very porous material that relies on air pockets trapped between minute glass rods to reduce heat transfer. The ability for air to move freely through fiberglass is what makes it such an ideal material for furnace filter. Unfortunately, when air moves around so does heat, and this property is the primary reason that low density fiberglass performance can be impacted by convective loops under extreme temperatures and experience ‘wind washing’ outside of sealed laboratory testing chambers.


In contrast, EnergySeal’s seamless insulation systems are spray applied and complimented with extensive air sealing. The ‘cellular’ structure of our spray applied systems help to stop air movement and thermal degrading convective loops from penetrating the cavity. EnergySeal’s seamless system R-values are largely unaffected by extreme climate conditions or wind pressure. Even when sprayed at an R-13, our airtight and seamless insulation system can outperform an air permeable layer of R-30 insulation subject to the same air pressure and temperature differentials.

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