Differential pressure switches can be installed in different ways. The pictures show three different approaches to installation. Below you will find a brief description of each application with an example.
- Monitoring the subatmospheric pressure (A):
This type is used to measure negative pressures relative to the surrounding atmosphere. For example, in a clean room or laboratory where it is critical to maintain a precise negative pressure environment to prevent external contamination. The differential pressure switch (P2) is internally connected to the room, while the reference side (P1) remains open to the atmosphere. The pressure switch can trigger an alarm if the negative Pressure drops, indicating that the integrity of the room has been compromised. - Filter monitoring (B):
To maintain air quality and ensure efficient operation of HVAC systems, the differential pressure switch is installed with port P1 upstream of an air filter unit and port P2 downstream. This configuration is typical in HVAC systems to detect when filters accumulate particles and cause a pressure drop that could impede airflow. The switch is triggered when the pressure drop exceeds the acceptable range, indicating that the filter needs to be cleaned or replaced. - Fan monitoring (C):
In applications such as transit systems or industrial ventilation, it is vital that fans move air effectively to ensure air quality and safety. The differential pressure switch is set so that port P1 downstream of the fan measures the discharged air pressure, while port P2 is positioned upstream to measure the intake pressure. The differential pressure switch continuously monitors the operating efficiency of the fan by observing the pressure difference generated. If the pressure differential falls below a certain threshold (and triggers the pressure switch), this could indicate a malfunction or wear of the fan, requiring inspection and maintenance.