The Design and Development of Relative Humidity Control Systems for Negative Pressure Airborne Infectious Isolation Room

Abstract

This research aims to: 1) build an airborne infectious isolation room according to the standard of the Engineering Institute of Thailand, 2) develop a system to control air temperature and relative humidity in AlIR according to the standard, and 3) develop a system for measuring weather conditions, displaying, and giving notifications through a smartphone. The experimental procedure was as follows. The researcher constructed an airborne infectious isolation room according to the standard of the Engineering Institute of Thailand based on Model no. 3. There is a system to measure weather conditions and display them in real time via a smartphone and LCD display. If the value is lower or higher than the criteria, there will be a notification via sound and flashing lights in front of the AlIR room and via a smartphone. The air temperature is controlled by adjusting the air conditioner temperature at 21-24 °C. The relative humidity is reduced by the principle of desiccation with silica gel beads. The dehumidification system contains 2 kilograms of silica gel beads. The result appeared that the developed system was able to control the relative humidity in the range of 40-60%RH. The airflow rate passing through the desiccant is 156 CFM and the wind speed is 8.76 m/s. The average water vapor absorption efficiency is 9.9%. The moisture removal capacity (MRC) is 0.5 kg/h while the air exchange rate is 16.57 ACH.