Fig. 4. Cooling performance of the TRE cooler for objects with above-ambient temperature.
(A) Schematic of the test setup. The thermostat is used to simulate a hot device with a specified heating temperature or power. (B) Power of incident sunlight and (C) cooling power of the TRE and radiative coolers at 50°C on a clear day. The cooling power of the TRE cooler is more than twice as much as that of the radiative cooler. (D) Power of incident sunlight and (E) temperature profiles of the TRE and radiative cooler with a heating load of ~200 W m−2 on a clear day. The temperature of the TRE cooler is >15°C lower than that of the radiative cooler. (F) Power of incident sunlight and (G) cooling power of the TRE and radiative coolers at 50°C on a cloudy day. (H) Long-term temperature profiles of the TRE and radiative coolers with a heating load of ~200 W m−2 on a cloudy day. Blue and gray shaded areas denote cloudy daytime and nighttime, respectively. The TRE cooler performs much better cooling and has excellent cooling stability.