Technology Highlight

V-KOOL® was originally developed for America’s space and defense programs and represents an important breakthrough in surface and particle science. It works through a patented process known as sputtering in which tiny particles of exotic metals are embedded in optically clear, durable polyester film.

V-KOOL® is spectrally selective and allows in 73% Visible Light, while blocking over 90% infrared spectrum. This means your window remains Visibly Clear but cuts out 55% of the Solar Heat. No other product can match V-KOOL's® performance. When applied to your windows, V-KOOL® forms a virtually clear barrier. That means less need for expensive air conditioning and electric lighting, making V-KOOL® a great way to help control soaring energy costs.

V-KOOL®, Inc (USA) is an ENERGY STAR Buildings Ally supporting energy efficiency and pollution prevention. V-KOOL® has awarded the industrial accreditation for its good product quality.

Spectrally Selective is better

Solar radiation on glass is expressed by its transmission, reflection and absorption. Thus, on a clear glass, Transmission is 83%, Reflection is 8% and Absorption 9%. This absorbed energy is re-emitted outward and inward via convection and re-radiation. Thus, 3% is re-radiated inward and 2% is rejected outward. Consequently, the Total Solar Energy Rejected is 10% and the total energy admitted is around 90%.

Spectral selectivity is the quality of having solar/optical properties which vary across the solar spectrum. This means the material allows a high transmission of visible light but a low transmission of solar gains. Spectrally selective window film is any film that reduces the amount of heat entering a building without altering its appearance. Most spectrally selective films are virtually undetectable to the naked eye, as they allow in at least 70% of visible light.

Spectrally selective films block a comparable amount of heat to traditional films without darkening the interior of the building. This eliminates the need for improved lighting which could cancel out any potential energy savings. Traditional films would darken storefront windows, while spectrally selective films would allow passersby to view the merchandise on display. Another advantage of spectrally selective film is that it can be applied to specific areas that receive a lot of sunlight without appearing out of place, whereas traditional films would need to be applied to the whole building for visual consistency.

V-KOOL® is designed to replace retrofit tinted and reflective glazing or films and all other products that help control heat gain. Tinted glass or film cuts out the light while allowing infra-red transmission. Dark tints have high heat absorption rate that result in radiant heat and create thermal stress on the glass. Reflective glass or film works by equally reflecting all wavelengths across the solar bandwidth. Hence, to obtain better solar control, the visible light transmission has to be reduced and the visible light reflectivity will increase. In addition, reflective glass or film creates the ‘one-way’ mirror effect under certain lighting conditions. This means that views through these windows at night will be obscured because of internal reflection. It also becomes a safety and security hazard when applied onto car windows.

How does V-KOOL® lower electric bills?

V-KOOL® will reduce air conditioning operating costs while increasing the comfort level of homes, buildings and vehicles. V-KOOL® blocks off about 50% of the total solar energy gain through the windows. In addition, because V-KOOL® lets in more daylight than tinted or reflective films, home and building occupants will be able to reduce the use of interior lighting. Reducing the necessity for artificial lighting again reduces electricity cost.

How V-KOOL® better than the others

UV-Vis-IR Transmittance Spectra of V-KOOL®

1. Curves shifted to right indicated UV transmission has been blocked.

2. All three V-KOOL® curves have significant effect of blocking IR (wavelength beyond 780nm).

3. V-KOOL® products retain high percentage of sunlight transmission.

UV / IR Transmittance and Reflectance comparison

1. The left side graph shows V-KOOL® has the best UV-IR blocking rate among the four samples.

2. The right side graph shows V-KOOL® has the greatest IR Reflectance rate among the four samples.

V-KOOL® applied to Tinted Glass and Reflective Glass

1. Right side: V-KOOL® can also apply to tinted glass with significant heat blocking result.

2. Left side: V-KOOL® applied to reflective glass with significant blocking rate of Infrared.

How V-KOOL® film compare in clarity

V-KOOL® retains its transparency in spite of the metal and adhesive coatings and does not interfere with visibility when applied to the windows. The coating blocks off infra-red heat and ultra-violet radiation without significantly reducing the visible transmittance.


VK70 offers the best balance heat rejection and daylight transmission. VK70 will allow 70% of the light to transmit while rejecting 55% of the heat. It is virtually clear and will maintain the architectural integrity.

  • Visible Light Transmittance
  • Ultraviolet (UV) Rejection
  • Total Solar Energy Rejected
  • Infrared Rejection
  • Shading Coefficient


VK75 will give you the highest light transmission, but has less solar heat rejection than VK70.

  • Visible Light Transmittance
  • Ultraviolet (UV) Rejection
  • Total Solar Energy Rejected
  • Infrared Rejection
  • Shading Coefficient


VK40 is the solution when you are trying to reduce some glare while maximizing your heat control. VK40 will allow 43% light transmission while rejecting 65% of the heat.

  • Visible Light Transmittance
  • Ultraviolet (UV) Rejection
  • Total Solar Energy Rejected
  • Infrared Rejection
  • Shading Coefficient