AHU SCADA Software
₹ 1,00,000AHU pre-fine and HEPA filters are crucial for air quality, and their performance is specified by efficiency ratings, material, and physical dimensions, with HEPA filters providing much higher filtration than pre-fine filters.
The status of AHU pre-filters and HEPA filters is typically indicated by monitoring the differential pressure across the filter using devices such as Magnehelic gauges, differential pressure switches (DPS), or digital differential pressure monitors/transmitters (DPT). An increase in pressure drop over time indicates filter clogging.
They require manual reading and regular observation by maintenance personnel.
Differential Pressure Switches (DPS):
A DPS is a device with a pre-set pressure limit. When the differential pressure exceeds this limit, the internal switch changes its contact status (from open to close, for example), sending an electrical signal or alarm to a building management system (BMS) or a local indicator.
These are used for triggering alarms when a specific "dirty filter" threshold is reached.
Digital Differential Pressure Monitors/Transmitters (DPT):
These micro-controller-based devices provide continuous, real-time digital display of the differential pressure.
They often feature high-bright LED or color LCD displays, have user-selectable high/low set limits for alarms (including an inbuilt buzzer), and offer advanced connectivity options like MODBUS RTU RS-485 serial communication for integration with PLC, SCADA, or BMS systems for remote monitoring and data logging
Filter Status Indicators The primary principle for monitoring filter status is measuring the pressure difference (pressure drop) between the upstream (high pressure side) and downstream (low pressure side) of the filter. As contaminants build up, resistance to airflow increases, the differential pressure rises, and the indicator signals a need for maintenance or replacement. Common indicator types include:
Magnehelic Gauges (Analog):
These are simple, U-shaped analog manometers that provide a local, visual reading of the pressure difference, usually in units of Pascals (Pa) or millimeters of water column (mm WC).
AHU Filter SpecificationsThe primary distinctions between pre-fine and HEPA filters in an Air Handling Unit (AHU) system are their filtration efficiency and the particle sizes they target. Pre-filters capture larger, coarse particles to protect the more sensitive, high-efficiency HEPA filters that follow in the air stream.AHU Display SpecificationsAHUs are often equipped with digital display units or differential pressure gauges for real-time monitoring of filter performance. Key display specifications include:
Differential Pressure Monitoring: This is the most crucial display feature, showing the pressure difference across the filter. As a filter collects contaminants, the pressure drop increases. Manufacturers recommend a final pressure drop (e.g., 250 Pa for pre-filters, up to 500 Pa for HEPA filters) at which point the filter must be replaced to maintain airflow and energy efficiency.
Digital Display Unit: These units typically show real-time pressure readings, often with a clear visual or audible alarm to indicate when filter changes are necessary.
Integration: Display units are often designed to integrate with Building Management Systems (BMS) for centralized monitoring.
Operating Range: The display/gauge should be suitable for the typical operating temperatures and humidity within the AHU (e.g., -10 C to 50 C, up to 100% RH)