An Exploration Study on the CO2 Concentration in Several Air-Conditioned Classrooms Located in Ho Chi Minh City

The South of Vietnam has a tropical humid climate: the temperature does not significantly vary in the year and there are only two seasons: the dry and the rainy one. The months with highest temperatures are usually from April to June, but the air temperature is rarely more than 35 ℃. The rainy season is currently from June to November. During this season, the rains (usually occurring at the end of the afternoon) enable to refresh the ambient in the evening. Therefore, in general, the natural climatic conditions of the Southern of Vietnam are favorable for bio-climatic architectural designs, which are a basis for sustainable building. Vietnam’s economic boom, however, went along with more resource-intensive lifestyles and changing demands of thermal comfort, particularly driven by the rapidly emerging urban middle class population. One consequence is that the use of air-conditioners has become increasingly popular in Vietnam. Also places of tertiary education get increasingly equipped with air conditioner units, which get equally used during dry and rainy season. This paper presents an exploration investigation on the CO2 concentration in the air-conditioned classrooms at a University in Ho Chi Minh City, Vietnam. The measurement equipment used was by Testo® which could measure the air temperature, the air relative humidity and the CO2 concentration. The measurements could be performed during a long period of time with the data continuously recorded and sent to the cloud by Wifi. The results showed the high CO2 concentrations in the classrooms investigated, due to the high number of people within a closed space, without any aeration. The results obtained show the high relevance to take into account proper measures for air-conditioned spaces, to enhance the air-quality and the health of the students and teacher using classrooms in Vietnam.