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Filter Control - Energy Savings Over Time

Application Description | Traditional solution | New standard 
Click here to read more about: PID Control, VVC plus

Less energy consumption occurs with clean filters, than would occur without the filter control strategy, because the drive will automatically maintain a reduced flow and lower fan discharge pressure when the filters are clean.
More energy consumption occurs with dirt loaded filters, than would occur without the filter control strategy, because the drive will automatically increase discharge pressure to overcome filter resistance and maintain a constant flow when the filters are clogged.
The increase in energy consumption with clogged filters is more than offset by the reduction in energy consumption with clean filters. Pressure increase across a filter is not linear with filter dirt loading, 85% to 90% of the filter life occurs at less than 40% of the filter final pressure drop. Therefore, most of the filter life span contributes little to filter pressure drop increase. A strategy of keeping the flow constant, raising the fan discharge pressure only when needed, will produce energy savings as well as significantly extending the life of the filter. Typically, CAV systems are considerably oversized by a "safety" factor, which means design airflow is reached at less than 100% fan motor speed, adding to the potential savings.

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