Paul Novus F7 G4 filter set

High-quality MPL filter vs Z-line filter

More and more filter shops try to gain extra profit from offering nonstandard lower quality filters. The most common situation is where a so-called Z-line filter is offered instead of an MPL (mini pleat) filter for a similar price. What is the difference between these filters?

1. 6-8 times larger filtering surface of MPL filter. Lower pressure drops, lower energy consumption, longer service term.
2. Higher filtering efficiency. MPL filters are used for G4-F9 classes (Coarse, ePM10, ePM2.5, ePM1). Z-line filters are used for G3-G4, rarely for M5. M5 or higher efficiency Z-line filters create high resistance: high-pressure drops, more noise, and high energy consumption.
3. Airtightness. In some Z-line filters filtering material is not glued to the frame. Part of pollutants just goes through this connection as it is less air resistance in that area. The material of most MPL filters is bonded to the frame.

How does the filter type affect ventilation unit performance?

There 2 main types of airflow control in the market: variable airflow and constant airflow. Air handling units with constant airflow are equipped with pressure sensors.

If the unit is without a pressure sensor, filter contamination gives higher resistance, and therefore airflow decreases. MPL filter (blue line) has a lower initial pressure drop, therefore it takes much more time to get fully contaminated. Also, a larger filtering surface means that it can capture much more dust.  

Z-line filter (red line) will not only give higher initial pressure resistance but due to the small filtering surface will get dirty more quickly.

If the ventilation unit has a pressure sensor for constant flow mode, airflow will remain the same.

MPL filter will start with lower pressure resistance at a lower power consumption point (blue line). Due to higher dust holding capacity it will take much longer to get fully contaminated than the Z-line filter (red line). Fan power consumption directly affects noise emissions. Therefore, units with Z-line filters will work louder.

To avoid noise and fast contamination issues, Z-line filters might be:

  • Lower filtering efficiency
  • Low airtightness (material not bonded to frame).

It will lead to dust accumulation in the ventilation unit and duct system, and also lower indoor air quality.

We always recommend using the same type of filters as in the original unit. Most of the ventilation manufacturers choose MPL filters for better energy and sound performance.

Your benefits of choosing the same class MPL-type filter:

  • Time and cost savings:
    • Less frequent changes
    • Lower energy consumption
    • Longer service time
  • Smoother unit performance:
    • Lower initial resistance
    • More silent performance
  • Ecological factor
    • Less waste as fewer filters are needed.
  • Better indoor climate
    • MPL filters usually have better filtering efficiencies.

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