Basic Documentation

Table Of Contents

Healthcare Facilities

Infectious Isolation Rooms

Infectious isolation rooms in healthcare facilities are intended to ensure that the direction of

airflow is always into the room, thus preventing the spread of disease to persons outside of

the room, particularly the healthcare workers. The need for providing negatively pressurized

infectious isolation rooms has become more focused because of the resurgence of the

contagious disease Tuberculosis (TB). Since Tuberculosis is highly contagious, the Centers

for Disease Control and Prevention published guidelines for preventing its transmission

These guidelines call for a minimum room negative static pressure of 0.001 inches w.c. (0.25

Pa) for infectious isolation rooms along with a minimum room ventilation rate of 6, and

preferably 12, air changes per hour (ACH).

In actual practice, a 0.001 inches w.c. room static pressure is quite low and impractical to use

as design criteria. A more practical isolation room static pressure level is at least 0.005

inches w.c. (or higher) since this level is more readily maintained and is a necessary

minimum level to enable measurement of the room static pressure as well as continuous

monitoring.

Protective Isolation Rooms

Protective isolation rooms require positive pressurization to ensure that room airflow remains

outward from the room, therefore preventing infectious pathogens from entering the room.

Protective isolation rooms are intended to prevent a patient from being exposed to airborne

pathogens outside of their room. This type of isolation room is needed for patients and

associated medical procedures that are susceptible to infection including organ transplants;

burn; bone marrow and leukemia patients; and for treating AIDS patients who have highly

compromised immune systems.

Static Pressure Control by Airflow Tracking

Airflow tracking is the preferred room static pressurization control approach for all types of

healthcare facility room pressurization applications. This includes operating rooms, nurseries,

and medical laboratories as well as both infectious and protective patient isolation rooms.

Airflow tracking maintains proper room pressurization (negative or positive) for both constant

air volume (CAV) room ventilation systems and variable air volume (VAV) room ventilation

systems.

1994 Guidelines for preventing the transmission of Mycobacterium and Tuberculosis in Healthcare facilities.

The CDC guidelines also recommend that isolation room static pressure be monitored daily. This can be done using a visible

smoke or by a permanently mounted static pressure sensing device that provides continuous indication of room static pressure.

Siemens Building Technologies, Inc. 27