How It Really Works

Microsphere Fundamentals

ThermaCote® contains billions of hollow ceramic microspheres, typically between 50 and 100 microns in diameter, suspended in a water-based acrylic resin.
Each microsphere is filled with air, forming a natural thermal break that reduces conductive heat flow through the coating.
The spherical structure disrupts heat transfer pathways at a microscopic level, improving the thermal performance of the surface.
The coating is seamless and flexible, allowing it to conform to complex surfaces and form an uninterrupted thermal barrier.

Radiant Heat Reflection

ThermaCote® is formulated with infrared-reflective ceramic technology, designed to deflect radiant energy across a broad IR spectrum (2–14 µm).
This reflectivity helps bounce radiant heat away from the building envelope, reducing both summer solar gain and internal heat loss.
Independent lab tests show that ThermaCote® can reflect up to 80% of infrared radiation, depending on the substrate and application conditions.
The result is a more stable internal temperature, reduced strain on HVAC systems, and improved occupant comfort.

Thermal Emissivity & R-Value

Emissivity Explained – Final Correct Version

Emissivity (ε) measures how effectively a surface emits thermal radiation, ranging from 0 (perfect reflector) to 1 (perfect emitter).
ThermaCote® has an emissivity of approximately 0.84 on interior surfaces, meaning it emits most of the heat it absorbs.
But it's highly reflective in the infrared (IR) spectrum, especially for incident radiant energy — meaning it reflects radiant heat before it is absorbed and converted into thermal load.
This makes ThermaCote® particularly effective on internal walls and ceilings, where it can reflect radiant heat back into the room, improving thermal comfort and enhancing the performance of infrared heating systems.
On external surfaces, ThermaCote® reflects a significant portion of solar infrared radiation, reducing heat absorption and helping to cool the building envelope.
ThermaCote® is not a low-emissivity coating, but a high-performance infrared reflector that functions across conduction, convection, and radiation to reduce total heat transfer.

Effective R-Value

ThermaCote® provides a certified thermal resistance (R-value) of 1.87 m²·K/W at just 1 mm thickness, offering high-performance insulation in an ultra-thin form.
This allows it to be applied where traditional insulation may be impractical—such as in retrofit projects, constrained spaces, or uneven surfaces.
ThermaCote® acts on all three modes of heat transfer:
- Conduction: Air-filled microspheres reduce thermal bridging.
- Convection: The microstructure seals surface air flow, limiting convective loss.
- Radiation: IR-reflective particles deflect radiant heat from internal and external sources.
This multi-mode performance makes ThermaCote® a powerful thermal barrier, complementing traditional insulation or acting as a standalone thermal upgrade.

“Action at the Interface”

ThermaCote® bonds directly to brick, render, concrete, wood, steel, and many other surfaces, forming a continuous thermal layer that fills micro-cracks, pores, and joints.
Unlike traditional insulation materials, it doesn’t leave gaps or require fixings, ensuring complete surface coverage even on irregular structures.
UK field studies have shown that ThermaCote®-coated walls can be up to 2 °C warmer in winter compared to uncoated equivalents—clearly demonstrating a reduction in heat loss.
This “action at the interface” means even heritage buildings or older properties with thermal bridging challenges can be upgraded without invasive works.