It is paramount for schools to put safety first as students prepare to return amidst all the concerns of the coronavirus. An isolation area, separate from any other spaces in the school where medical care is provided, means students displaying symptoms can safely remain isolated until they are picked up.
Isolation rooms are designed to prevent dangerous particles from spreading beyond a specific area. To accomplish this, isolation rooms are negatively pressurized. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 170, a standard for hospitals, requires a negative pressure of at least -0.01" WC for an Airborne Infection Isolation Room (AIIR). It is common to have isolation rooms with -0.02" WC to -0.03" WC to account for variances in an HVAC system. With the isolation room negatively pressurized relative to the hallway or outside area, any aerosols or particles in the air will not be able to escape the room. Negative pressure draws clean air into the room. To further prevent chances of contamination, air from isolation rooms should not be returned to the building's main air supply system. In a typical hospital isolation room, this exhaust has dedicated ductwork with high-efficiency particulate air (HEPA) filters that moves it to ventilation stacks on the roof where it is exhausted out and diluted by atmospheric air.
It is important to note that negative pressure does not mean the absence of pressure. Rather, it means the room or space in question has a lower pressure than the space around it. This control of the differential pressure between an isolation area and the surrounding space helps to limit aerosol and particle transmission.
Adjusting a building's HVAC system to achieve negative pressure and subsequent removal of contaminated air in a particular space is possible. However, such changes to an established HVAC system can be time-consuming, complex, and expensive. A portable unit like Setra's Negative Pressure Air Quality Module allows for a quick, cost-effective way to convert a room into an isolation room.