The Energy and Comfort Performance of a Lightweight Translucent Adaptable Trombe Wall in Different Buildings and Climates

J.A. van Unen (Faculty of Civil Engineering & Geosciences, Delft University of Technology)

CHALLENGE - A traditional Trombe wall is known as a high thermal-mass wall, situated behind a window of a room and separated by an air cavity. The idea behind using a Trombe wall is that heat, ventilation and comfort can be passively generated by using the ‘free’ energy of the sun. Because a traditional Trombe wall is heavy, blocks daylight and cannot be adjusted to changing environmental conditions and seasonal differences, a new and innovative version was devised by the Double Face research team (4TU).

SOLUTION - The innovative version is called a lightweight translucent adaptable Trombe wall (LTATW) and is about five times lighter than a traditional Trombe wall. In addition, the wall is translucent and can rotate around its axes. The lower weight and translucent character are achieved by applying a phase change material in combination with aerogel, instead of stone or bricks. The present study investigates the influence of eight parameters (climate, building function, orientation, age, building method, room size, window size and type of glazing) on the energy and comfort performance of the innovative Trombe wall.  An initial simulation model was developed in Matlab/Simulink, which was subsequently validated using a cross-comparison with results from DesignBuilder. The results of the simulations are values for the reduction or increase in energy demand for heating and cooling, expressed in percentages or in kWh. In addition, the influence of each individual parameter on the performance of the Trombe wall was investigated using modeFRONTIER.

BENEFITS - It can be demonstrated with modeFRONTIER that the average reduction in heating energy demand equals 21.3% of the initial energy demand or 127.7 kWh in absolute sense. The standard deviation of the reduction in percentage is equal to 28.2% and the standard deviation of the reduction in absolute terms is equal to 197.5 kWh.