Passive control methods of Kerala traditional architecture for a comfortable indoor environment: Comparative investigation during various periods of rainy season

The traditional architecture of Kerala, a state in India lying along its southwest coast, is known for its use of natural and passive methods for a comfortable indoor environment. Although there have been attempts to analyze the traditional architecture of Kerala, they were focused only on qualitative approach. An investigation was thus initiated by the authors to understand the passive environment control system of Kerala traditional architecture in providing better thermal comfort, by continuously monitoring thermal comfort parameters of a typical traditional residential building over a period of time. The inferences of the first phase of the investigation carried out during winter and summer seasons, lasting about half of the year have already been published. This paper illustrates the inferences of the second phase of the investigation that is carried out during the rainy season of the year. A comparative analysis with the results of the winter and summer periods is also incorporated. The investigation has revealed that, when the outside ambient temperature is below normal, the building system tries to maintain the indoor air temperature at a higher but comfortable level and when the outside temperature is above normal, the indoor is kept at a lower but comfortable level. It is found that a continuous gentle wind flow is maintained inside the building irrespective of the wind outside. The required level of thermal comfort is achieved by maintaining a balanced level of temperature and relative humidity along with a continuous and controlled airflow inside the building irrespective of seasons.