Study of Air Conditions and Energy Impact in Air Conditioning Systems from Ventilation in COVID-19 Patient Wards

DOI: 10.14416/j.ind.tech.2024.12.002

Abstract

Enhanced ventilation from modified spaces in hospitals, including both positive and negative pressure rooms, leads to an increased thermal load due to the introduction of outside air with higher enthalpy into the building's interior, affecting the energy consumption of air conditioning systems. Additionally, the introduced outside air impacts the adjustment of indoor air conditions. This study investigates the indoor air conditions of COVID-19 patient wards that have been designed and modified to prevent the spread of infection within the treatment area. Continuous measurements of energy consumption in the air conditioning system, dry bulb temperature, and relative humidity of various rooms in the patient wards were conducted under real outdoor air conditions, introducing clean air at 6 air changes per hour (ACH) into positive pressure rooms and extracting air from negative pressure rooms at 12 ACH. Comparisons were made between scenarios of disease outbreaks necessitating 100% ventilation to prevent infection spread and scenarios where the ventilation system is turned off in patient wards for treatment in non-outbreak conditions. The study found that turning on the ventilation system to prevent infection transmission significantly increases the energy consumption of the air conditioning system. This is due to the increased thermal load from using outside air to pressurize positive pressure rooms, the infiltration of outside air into negative pressure patient rooms, and the impact of necessary patient care activities that add moisture to patient rooms. The air conditions in the positive pressure rooms were comfortable. However, the air conditions in the patient rooms were outside the standard range because the ward was not equipped with an air humidity control system.