CoolPaint: Heat Reflective Emulsion Paint

How CoolPaint saves energy costs?

CoolPaint is a type of heat reflective emulsion paint. Inside there are transparent polymeric beads. These beads are able to reflect the infrared portion of solar radiation. Near-infrared wavelength is in the vicinity of 45% of the total solar radiation. The other components making up solar radiation is ultraviolet (UV) being 8-9% and visible light at 46-47%. Heat signature can differ up to 10-12 deg C depending on the base substrate material such as glass, concrete or metal sheeting. These savings translate into energy savings in air-conditioning, enhances comfort and building maintenance.

Comparing CoolPaint and normal emulsion paint

In CoolPaint, there is a range of colours that can be mixed if the customer so wishes. The best solar reflectance for the colour type is white.

What makes CoolPaint different from normal white emulsion paint?

  1. CoolPaint has the hydrophilic ability to self-clean. Titanium dioxide and zinc oxide are mixed into the paint to support self-cleaning. Hydrophilicity is achieved by breaking down the surface tension of water molecules. By doing so, the water molecules act to wash away dirt and grime from the surface of substrates. Normal paint does not and gets dirty easily.
Figure 2 Difference between hydrophilic and hydrophobic effect on water. (Image from

2. All paint regardless of content reflects heat best with light colours or pigments. This is where the similarities end. CoolPaint reflects IR but the normal white paint has a higher bias to absorb the IR radiation instead.

Even compared to other competitors, CoolPaint has a markedly lower heat signature.

On comparison for dark pigments, CoolPaint will still reflect a larger percentage of solar infrared compared to normal dark paint. Figure 4 shown using an IR thermal camera compares both CoolPaint and regular black paint.

Where can CoolPaint be applied?

CoolPaint being an emulsion-based paint can be applied on most surfaces. The base primer or sealer allows bonding with substrates such as concrete, masonry, mortar, ceramic, metal and glass materials. There is no restriction for use on existing or new roofing as there is minimal additional weight. More importantly, under JIS A6909, it complies to meet various testing requirements. These tests are for acidity, alkaline, accelerated weather resistance and permeability tests.

Apart from JIS A6909, other tests based on ASTM E903-12, ASTM E971-11 and CIE 130-1998 shows compliance to specular reflectance requirements under URA’s Acceptable solutions for building façade.

There are two main types of heat reflective surface coatings. These are cementitious and elastomeric coatings. CoolPaint is the latter as the base is acrylic resin. These properties provide a longer design lifespan compare to its cementitious competitors. Being resin or silicone based, it has better stretch ability or elasticity properties under rain, hot and cool night conditions. This means CoolPaint is suitable for different kinds of climate and countries.

Considerations: Pros and Cons

CoolPaint has gone through well-documented benefits via research and testing. It is best to give a fair overview of the considerations to CoolPaint.

Table of pros and cons


CoolPaint may become a significant contributor towards reducing our climate changes. We have to understand the technology better especially its pros and cons. Often critiques would criticize CoolPaint’s heat reflective ability. This is often done without the correct knowledge of the technology itself. Numerous testing has shown to the contrary and the only way forward is to see it for oneself.

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