Transwall versus trombe wall: Relative performance studies

Abstract This paper compares the performance of two types of thermal storage wall, namely Transwall and Trombe wall. Both of them are located directly behind the south facing glazing of a wall. A Transwall is essentially a transparent modular wall. It consists of water in a container made of parallel glass walls and has a partially absorbing plate at the centre parallel to the glass wall. Thus, it partially absorbs and partially transmits solar energy. A Trombe wall consists of either masonry or water in opaque containers and does not transmit solar energy. The relative performance of these has been studied to find out their suitability for a cool climate of North India. Mathematical models have been developed to predict the thermal performance in terms of the heat flux entering the living space through these walls. Numerical calculations for Srinagar (India) climatic conditions show that the Transwall is more effective than the Trombe wall to meet the daytime heating load, but from load levelling and both day and night performance points of view, a water Trombe wall is better. The results are quite general and can be extended to any place having similar climatic behaviour.