Flat-plate radiative cooling and solar thermal collector numerical model evaluation

IntroductionLow-grade energy sources are making way in building energy supply of domestic hot water, space heating and cooling. One of these sources is radiative cooling which takes advantage of the sky as heat sink. However,... [ view full abstract ]

Introduction

Low-grade energy sources are making way in building energy supply of domestic hot water, space heating and cooling. One of these sources is radiative cooling which takes advantage of the sky as heat sink. However, some improvements are required and its coupling with solar collection is seen as a promising solution.

Little research has been conducted in this issue, and there is no research in the development of a numerical model capable of reproducing this combination of technologies.

Methodology

A numerical model coupling both technologies is developed and presented. The model is implemented in TRNSYS as a new type. Special care was taken in the definition of the radiation model.

Results and discussion

Results show the potential of the RCE to perform the double functionality, as solar thermal collector and as radiative cooler. For spring period, the solar thermal energy collected is 10.90 kWh/m2 and radiative cooling energy is 1.60 kWh/m2, whereas for the summer period the solar thermal energy collected is 14.96 kWh/m2 and radiative cooling energy is 0.88 kWh/m2.

Results demonstrate the potential of this technology leading to the next step of developing an experimental prototype.