Pressure monitoring for HVAC filters. If you want more to be done, contact us!

Differential Pressure Switches

A differential pressure measurement device is installed across the filter bank to identify the appropriate change-out times. Pressure drop switches are used to provide an alarm input to our Building Automation System that alerts operators to change the filter at the right time.

Optimum Use of Filter

Prevent Bypass of Polluted Air

Save Energy

Automate Alarms

How it Works


HVAC AHU Differential Pressure Switch

Do not rely on a visual inspection of the HVAC filters alone, since medium and high-efficiency filters that appear “dirty” often have not reached their optimum efficiency levels due to depth loading. In fact, filters should appear dirty. This is a good indication they are doing their job. As a filter loads up with particles, it becomes more efficient at particle removal, but increases pressure drop through the system, thus reducing air flow while consuming more energy.

This is where differential pressure switch comes handy. It recognises the right clogging levels of the HVAC filters and alerts the maintenance personnel to change the filters at the right time. The result is that the filters are used to the optimum level, do not allow bypass of unfiltered air and at the same time, do not lead to use of inefficient use of electricity in the HVAC systems.

All filters – if loaded to excess – will become deformed, unload dust, and even “blow out” of their filter rack. When filters blow out, bypass of unfiltered air can quickly lead to problems such as clogged coils and dirty air ducts. Flow capabilities of the system fan may also be affected.



  • Use the HVAC air-filters to their optimum level

  • Prevent bypass of unfiltered air

  • Prevent clogging of coils

  • Prevent air ducts getting dirty

  • Prevent any stress on the fan system

  • Save energy

  • Prevent downtime