Optimal Characteristics of an Adaptive Windshield for a Solar Collector and Radiative Cooling Combined System
Abstract
Radiative cooling is a promising technology for space cooling which can be combined with solar heating applications, enabling the production of both energy demands –heat during daytime and cold during nighttime– in a single device; reducing the non-renewable primary energy consumption for space conditioning and domestic hot water. An adaptive cover allows a mode switch, enabling heat or cold production, by combining materials with suitable optical properties for each mode. Another effect derived from the usage of covers is the reduction of convective heat losses, enhancing the performance of the device. Glass covers have been used in solar heating applications; polyethylene has been widely proposed in radiative cooling applications while zinc-based compounds are transparent enough to solar and infrared radiation in the atmospheric window to be used in RCE applications. Smart materials show tunability of properties of radiative surfaces but upon this time, they have not been used as covers neither in radiative cooling applications, nor in combined radiative cooling and solar heating applications.