Courtyard as Tropical Hot Humid Passive Design Strategy: Case Study of Indonesian Contemporary Houses in Surabaya Indonesia

Courtyard in building contributes to indoor thermal environment. Courtyard element is commonly applied as passive cooling strategy in the design of boarding house in Indonesia. Courtyard has a potential aspect of being micro climate-modifier to reduce indoor air temperature during the day. This paper discusses the effects of courtyards on indoor thermal environment in Indonesian contemporary boarding houses using field measurement. This paper focuses on the indoor air temperature reduction of 5 courtyard houses design of the contemporary boarding house in Surabaya, East Java, Indonesia. The field experiment method was used for two physical environmental variables: the air temperature and relative humidity. Each sensor was shaded with a paper cups wrapped with the aluminum foil to prevent the effect of direct thermal radiation. Measurement was taken for approximately 23 days continuously in each building. The results of the measurement exposed that the form and enclosure element is pivotal in its thermal environment design consideration for tropical climate. Meanwhile, utilizing ventilation blocks as the primary enclosure also help reduce air temperature in hot-humid climates. The results showed that the indoor air temperatures in the courtyard and surrounding room were approximately 0.3-1.7°C lower than the outdoor air temperature during daytime. During night-time, indoor air temperatures inside swing to 0.8-1.9°C higher than the outdoor. The results of the thermal environment evaluation revealed that indoor air temperatures can be categorized as a neutral temperature of the measurement period. Therefore, the application of courtyards in contemporary boarding houses have proven as possible means of achieving sufficient cooling effects through full-day ventilation strategy, and showed improved performance when combined with ventilated blocks.