Effect of Simple Fans on the Positive Pressure and Air Change Rate in Container Construction

Abstract

For simple positive pressure container construction for medical purposes, accessible and convenient ventilation fans have been adopted to facilitate rapid construction; however, the ability to maintain the recommended minimal indoor air pressure of 2.0–2.5 Pa and air change rate of 2–3 times/hr (T/hr) in these facilities remains unclear. This study examined the air change rate required to maintain the positive pressure in a 20-ft container with simple ventilation fans as well as the changes in the indoor pressure when the grilles were open or closed. Inverter fans that move small air volumes were adopted for ventilation with air change rates of 2–18 T/hr, and grilles in different positions were opened in coordination with the fans to measure the relationship between the positive pressure in the container construction and the air change rate. The results revealed that a minimal air change rate of 6 T/hr was required to maintain the indoor pressure of 2.0 Pa in an enclosed space. When the vents were open, because of pressure relief, a minimal air change rate of 12 T/hr was required to maintain the pressure of 2.0 Pa. Moreover, the pressure became lower the farther a measurement point was from the fans or the closer it was to the vent. The research results verified the minimal fan ventilation capacity required for a container facility as well as the relationship between the distance from the opening of a ventilation fan or a vent and indoor pressure.