Semi-Transparent Water-Based Trombe Walls for Passive Air and Water Heating

Abstract

Trombe walls provide a passive source of heating and ventilation for buildings. However, Trombe walls can also cause overheating during hot and sunny weather conditions. In this work, we investigate the potential of a multifunctional Trombe wall design, comprising a tinted acrylic sheet submerged in a water wall that functions as a thermal storage medium. The tinted acrylic sheet absorbs incident light, which is then converted to heat and absorbed by the water. The proposed Trombe wall can function as a tinted semi-transparent window to add aesthetic value. Furthermore, heated water rises to the top of the Trombe wall where it can be removed, which provides the dual benefit of preventing overheating and providing a source of preheated water for applications within the building. Experimental results performed on a laboratory-scale Trombe wall prototype showed that the percentage of solar-simulated light energy incident onto the Trombe wall prototype, over a period of five hours, that was stored as thermal energy in the water increased from 60.3% to 83.2% when tinted glass was inserted in the water storage wall. Furthermore, the temperature of the water at the top of the Trombe wall reached ~56 °C, which is suitable to be used as pre-heated water in building applications.