Discharge Heat into Space
and Block Sunlight

What is "SPACECOOL" Radiative Cooling Material?


SPACECOOL is a high-performance, highly durable, flexible optical film.
The SPACECOOL material not only blocks heat absorption from sunlight and the atmosphere but also dissipates heat by radiating it into space,
making it lower in temperature than the ambient air with zero energy consumption.

SPACECOOL’s Radiative Cooling Technology


By taking advantage of naturally decreasing radiant cooling, our unique optical design enables the user to experience the highest level of radiative cooling performance in the world.

The unique multi-layered structure provides both heat shielding* and radiative cooling* functions.


It blocks sunlight and suppresses heat absorption (heat shielding with a reflectivity of 95% or more), increases infrared rays in the wavelength range of the “atmospheric window*”, and dissipates heat by radiating it into space (radiative cooling with an emissivity of 95% or more) all at the same time. *”Heat Shielding” defends against light energy such as sunlight by “reflecting” it.
*When light comes into a material, it either "reflects," "emits," or "transmits" (reflectivity + emissivity + transmittance = 100%). Therefore, it has been difficult to achieve both high reflectivity and high emissivity.

Heat transportation into space through the “atmospheric window”


Heat energy on the earth's surface that absorbs sunlight is converted into light energy in the wavelength range of the "atmospheric window" and transported into frigid space, where it is -270°C.

*Atmospheric Window:The atmosphere has wavelengths that pass light well (high transmittance) and wavelengths that absorb light well (low transmittance). Wavelengths with high atmospheric transmittance are excellent for transporting heat in the form of light energy into space, and the wavelength range of 8–13 μm, which is particularly transparent, is called the "atmospheric window.”

Converting "heat energy" to "light energy”


Matter absorbs light energy and converts it into heat energy, which raises its temperature. Thus, light energy from the sun warms the earth's surface and makes it hot during the day.
SPACECOOL increases the radiative cooling effect by converting ambient thermal energy into light energy in the wavelength range of the "atmospheric window.”

New radiative cooling technology
that differs from heat shielding and heat insulation


Unlike conventional technology that inhibits heat input and slows heat transmission, this new material not only blocks heat from sunlight and the atmosphere to inhibit heat absorption but also releases heat into space, creating temperatures cooler than the atmospheric temperature.

Proprietary technology

Demonstration Tests


Our engineers are conducting precise research and demonstration tests
to allow clients to fully experience excellent safety, comfort,
and economy of SPACECOOL.
They are carrying out research and testing on a daily basis
so that everyone can use the product without worry.

1 Grows cool
under the blazing sun!
Summer performance

Test comparing the reverse-side temperature of a steel plate painted with solar reflective paint, and another coated with SPACECOOL.
Test period
September 01, 2017

Solar reflective paint SPACECOOL

Reverse-side Temperature of Solar Reflective Paint Vs. Radiative Sky Cooling Material*

Cf) Solar reflective paint: Ambient air temperature +10 to 20°C, Steel plate: Ambient air temperature +40 to 50°C
*Reverse-side temperature of steel plates painted with solar reflective paint, and SPACECOOL

2 Highly durable UV resistance

The guideline for weather resistance to ultraviolet rays is approximately 10 years*.
*Actual durability may vary depending on the environment of use.
*The number of years estimated from xenon weather tests.
*It is not a guaranteed value.

3 Proof of Concept

The radiative sky cooling material was used for prefabricated houses, tents, trucks, containers, and the like, and its effectiveness evaluated.
Test period
From July 2020
Providing Value to People (Heat Stroke Prevention)

We conducted tests of radiative sky cooling tents compared to normal white tents.
We confirmed a difference of about -10°C in apparent temperature.* 1 *1 While the forehead temperatures of the subjects in the tents made from radiative sky cooling material were about body temperature, those in the regular tents were around 40°C. Thus, we confirmed a large difference in apparent temperature.

Apparent Temperature (Black body temperature)

  Radiative Sky Cooling Tent Regular White Tent
SubjectA 36.5℃※2 40.0℃※2
SubjectB 35.5℃※2 40.5℃※2
SubjectC 36.0℃※2 40.5℃※2
SubjectD 36.0℃※2 40.5℃※2
SubjectE 36.0℃※2 40.0℃※2
  • • It felt cooler than outside.
  • • It was hot, but I could probably stay inside a long time.
  • • I want to get out as soon as possible.
  • • 3 minutes is my limit. It feels dangerous.
  • • I can't stop sweating.

*2 Skin temperature (measured at head)

Providing Value to Business

White storage sheds were wrapped in radiative sky cooling material for the test.
• Roof temperature: 20°C cooler than white cabinet.
• Temperature inside shed: Up to 10°C lower than initial conditions.
Up to 6°C lower temperature compared to storage shed fully insulated with glass wool as thermal solutions.

Providing Value to Society (Energy conservation)

We applied radiative sky cooling materials to prefabricated houses for use at construction sites, and compared their electricity consumption with that of an untreated unit.
Electricity consumption from 9:00 AM to 5:00 PM was reduced 20% by presence of radiative sky cooling materials.



Our new material creates comfortable cooling while avoiding over reliance on using energy like electricity.
Protect important things from heat and allow everyone spend their days comfortable and safe.