Uncertainty Distribution of Air Infiltration Rates of Thai Detached Homes for Energy Model

Abstract

Air infiltration through building envelope is considered as a path of outdoor air ventilation in modern Thai detached homes where there is no outdoor air intake in an air condition unit. At present, there are limited studies of air infiltration rate through building envelope for Thai homes and such few studies are insufficient for establishing a database of air infiltration rate for evaluating home energy performance. This present study used a multi-zone airflow model to calculate air infiltration rates in 134 homes from 137 housing development projects located in suburban areas near Bangkok. The calculated air exchange rate (air infiltration) ranged from 0.33-0.58 h-1 with an average value of 0.43 h-1 (s.d. = 0.04). Compared to the ventilation standards, the calculated air exchange rates were approximately 1.7 times greater than the required ventilation rates defined by the ASHRAE Standard 62.2 (2007) and 93% of those achieved the required ventilation rate prescribed in the Thai Building Control Act B.E. 2522 (2015). Consequently, it has a potential to reduce air infiltration rate for modern Thai detached home to save home energy consumption. The default air infiltration rate typically used in energy models provided a maximum input error ranged from 7-65% when compared to the calculated air infiltration rates.