Assessment of Ventilation Efficiency in a Hospital using Carbon Dioxide Measurement

Abstract

This study had measured carbon dioxide concentrations in a 541-bed public hospital in the out-patient department; namely, eye clinic, pediatrics and pharmacy1’s waiting area. All has the cool air distributed from the HVAC system. Also, the in-patient departments were studied; namely, male private surgical ward (with air-conditioner), female general surgical wards (without air-conditioner) and male general medical ward (without air-conditioner). The measured concentrations were compared with the ASHRAE standard of 1,000 ppm. It was found that the carbon dioxide concentrations in the eye clinic were in a range of 1,013-2,524 ppm, while those before               the service time were 500-583 ppm. Similarly, the concentrations in pediatrics were 931-3,225 ppm, while those before the service time were 626-666 ppm. For the pharmacy1’s waiting area, the concentrations were 430-2,474 ppm, fluctuating all the time from the outside wind. In the male private surgical ward, the concentrations were                638-944 ppm. In the female general surgical ward, with natural ventilation through the doors and windows,                       the concentrations were 322-614 ppm, while those in the male general medical ward were in the range of 286-605 ppm. Both general medical wards with natural ventilation comply with the good ventilation criteria. Therefore, it was concluded that the out-patient department had insufficient ventilation comparing to the in-patient department. Numbers of the patient and outdoor air circulation were the main factors for these different results.                Keywords :  ventilation, carbon dioxide, hospital