Monitoring and controlling room pressure in laboratory and healthcare settings can do more than just ensure directional airflow (positive or negative pressure rooms). Proper room pressure also contributes to saving energy. Overpressure or under-pressure scenarios mean that airflow, or even temperature control, are not optimal.
When room pressures are designed in, and 
established via the building automation commissioning process, alarm limits are typically set within the high range and low range of the room pressure sensor. For example, an Airborne Infection Isolation (AII) room may have a high limit alarm of -0.01" WC. Often, the other end of the threshold, the low limit, is not given much attention. In this AII scenario, the low limit may just be set at the maximum of the sensor range; perhaps as low as -0.25" WC (an extremely negative room).
By employing a sensible band in the alarm limits of room pressure, like a high limit of -.01 and low limit of -0.04, the room pressure monitor will alarm on two conditions. Above -0.01 an alarm means that the room is no longer compliant with directional airflow codes, and is no longer safe to contain airborne pathogens. Below -0.04 an alarm means that there is too much air being conditioned and supplied to the space. The room is "too negative," and well beyond necessary safety and code compliance.
Alarming at both ends of the sensor ensures action is taken for both safety concerns and energy efficiency. For both AII and Protective Environment rooms, the most efficient way to measure, monitor, and alarm on room pressure conditions is using a monitor like the Setra SRCM.
CLICK HERE to learn more about Setra’s full line of pressure monitors.
