A preliminary study of hygrothermal performance of autoclaved aerated concrete blocks under hot humid climate of Thailand

This paper reports field investigation of the hygrothermal performance of autoclaved aerated concrete blocks (ACC) compared to other wall construction materials. The study was conducted under the tropical climatic conditions of Thailand where this debatable issue had not been yet seriously investigated. To this end, three small houses were built. The dimensions of each were 2.4 m x 2.4 m x 2.3 m. Every house was built using a different commercial material namely red clay brick, AAC block and lightweight concrete (LC) block with a plastering layer and no painting in both internal and external sides. The well insulated roof was built with grey colored concrete tiles and gypsum ceiling. The inclination of the roof was 30 to the horizontal plane. Tests were conducted with closed windows and doors. The effect of ambient humidity was simulated by using sprinkles spraying water at the four sides of each house. Experimental observation demonstrated that measured temperatures and humidity profiles were different among three sample houses. The red-brick wall had the highest temperature difference compared to the AAC and LC walls. The inter-penetrated moistures level existing inside each room was insignificant during normal weather condition. However, tests under high humid condition indicated good moisture prevention was observed at the AAC house. Within the AAC wall, the heat gain reduction into building is significant noticed that it is greater than LB and LC walls. The AAC block encourages the thermal comfort from studied experimentally.