Simulating Natural Ventilation in Residential Buildings Using Water Table Apparatus

Monisha Edwina Royan, Prasad Vaidya, Rashmin Damle | 2017


Over the coming two decades tropical regions like Asia will be the main driver of 40% increase in world energy consumption. India is seeing a rapid uptake of energy intensive methods for cooling buildings. Designing effective natural ventilation is essential for mixed-mode low energy cooling approaches. Analytical tools for designing natural ventilation flows for real buildings with elaborate geometry are either too simplistic to be useful or too complex to be accessible. The water table apparatus is an affordable tool to simulate air movement and visualize performance for architects, engineers and owners.

This paper demonstrates the use of the water table apparatus for natural ventilation to determine the quality of the air movement, distribution of air and the factors influencing them. The paper summarizes the construction of water table, validation of its results, and demonstration of its use as a design analysis tool. A scaled model of a residential apartment building is studied with parametrics for building orientation and window area. The simulated air-flow through the model is visualized with photographic documentation. Easily accessible graphic filters are used for post processing the information for quantitative analysis. Results of the air flow pattern are quantified in terms of temperature gradients, the effectiveness of natural ventilation, air change rates for each run. These results show the promise of the water table apparatus as an affordable and accessible analysis tool.