Filter comparison:filter fabric, Z-Line or Minipleat?

If we already have a ventilation system at home, we decided to purchase it for a specific reason. One of the most common reasons is to reduce heating costs, especially in winter, when the heat escapes along with the air during classic ventilation through the windows. Another of many advantages can be a continuous supply of fresh air and thus a reduction of CO2 in the interior, which increases the quality of living and comfort. However, in order for the ventilation system to meet the given requirements, air filters with appropriate parameters must be installed in the system.

There are still manufacturers on the European market who only supply filter fabric as original filters for their ventilation systems, which the user cuts to the required size and inserts into the ventilation system. This filter fabric is usually offered in filter class G3 - M5 according to EN 779.
As we have already explained in another article, these filter classes are not sufficient when it comes to supply air filtration. Dust particles smaller than 2.5 µm, which are most dangerous to the human organism, can only be captured by filter fabric of class M5 according to EN 779 to around 20%. The remaining 80% of the fine dust can reach our interior spaces.
Why do the ventilation system manufacturers not offer their customers filter fabrics with a higher filter class? Because they know that the fans in their ventilation systems would have to produce a significantly higher output in order to suck in the required amount of air through a finer filter fabric. This would shorten the useful life of the systems and the energy consumption would be significantly higher..
What if the customer still decides to purchase a filter fabric with a higher filter class and use it in his ventilation system? We tested this in our Pichler PKOM4 system..

Measurement under real conditions in the Pichler PKOM4 ventilation system

For the measurement, we used filter fabric marked F7 according to EN 799 with a height of 7 mm and a specified weight per unit area of ​​the material of 250 g/m² for the supply air. To filter the exhaust air, we used filter fabric with the designation M5 according to EN 779 with a surface weight of 150 g/m². Both of these filter fabrics are described by the manufacturer as filter medium intended for cutting.
We cut the filter fabric to dimensions of 30 x 30 cm, placed it in an extruded ABS frame and sealed it. In the ventilation system, the ventilation levels and thus the volume flow were gradually increased from 80 m³/h to 300 m³/h in 10-minute intervals.
For each individual ventilation level, the current electrical power consumption of the system was recorded using a MODBUS interface and a higher-level intelligent LOXONE system. At the same time, a Hutermann brand single-phase current meter was used for checking the socket.

Based on our measurements, it was determined that the current electrical power consumption displayed on the system corresponds almost exactly to the current power consumption measured on the single-phase current meter; the deviation is approx. 2% for 100 W instantaneous power, which is a very good result.
The following diagram shows the measurement results for both filter variants of the same filter class - when using filter fabric and when using the RUKATECH SafeLuft filter with MiniPleat construction:

The measurement was ended after reaching a volume flow of 270 m³/h because the system was not able to suck in the required 300 m³/h through the filter fabric. It is clear from the diagram that when using filter fabric, the blowers have to produce a significantly higher output in order to achieve the required volume flow. For a common volume flow of around 200 m³/h, the required performance of the system is more than 50% higher compared to the RUKATECH SafeLuft filters.
In order to be able to check what influence the filter surface actually has, we decided to carry out further measurements and use a pleated filter of filter class F7 according to EN 779 for the supply air and M5 according to EN 779 for the exhaust air, whereby the filter fabric has a fold density of 40 folds per meter at a height of 44 mm.
We then added this measurement to the previous diagram:

It can be seen that a marked reduction in the required power has occurred and the resulting curve of the pleated filters has moved closer to the results of the RUKATECH filters with MiniPleat construction. By folding the filter medium, the filter area increased almost fourfold and thus also reduced the pressure loss. A clearer difference is only noticeable at volume flows of approx. 250 m³/h, where the performance when using folded filters is around 30% higher than with the RUKATECH SafeLuft filters.
As a final comparison, we list all measured values ​​in percentages, with the performance values ​​when using the RUKATECH SafeLuft filters serving as reference values.

When using a filter fabric of filter class F7 according to EN 779 for the supply air and M5 according to EN 799 for the exhaust air, a 50% higher performance is required at a volume flow of 100 m³/h than with the RUKATECH SafeLuft filters.
This ratio increases exponentially and achieves an increase in power consumption of almost 90% at a volume flow of 270 m³/h. The ventilation system therefore has to work with almost double the performance.
If we fold the filter fabric with a fold density of 40 folds per meter, there is a significant reduction in consumption, which means that for volume flows of up to 200 m³/h it is no more than 20% higher than with the RUKATECH SafeLuft filters.

And the winner is RUKATECH SafeLuftt

Based on the results obtained, it was confirmed in real operation that the use of filter fabric of a higher filter class disproportionately increases the power consumption of the ventilation unit, places greater strain on the fans and certainly has a fundamental influence on the service life of the entire system. The operator should therefore not use these filter fabrics and instead use a different filter design or a lower filter class. However, there is the risk mentioned above that fine dust will reach our interior.

In contrast, pleated filters can deliver good results with air volume flows of up to 200 m³/h. However, at higher volume flows there is an exponential increase in the pressure loss and thus also an increase in the required power consumption.
It is also important to remember that folded filters achieve a fold density of 40-50 folds per meter. These filters therefore still have a significantly smaller relative area compared to filters of the MiniPleat design, where up to 150,200 folds/m are usually achieved. This primarily differs in the capacities of the filters, with a filter with MiniPleat construction being able to absorb a significantly higher amount of fine dust until the final pressure loss is reached thanks to the larger relative area compared to a pleated filter..
These folded filters either require more maintenance and regular cleaning on the part of the operator so that they do not become clogged, or they have to be replaced more often. Their use also increases the total electricity consumption of the ventilation system by an average of 20-30%..

The RUKATECH SafeLuft filters with MiniPleat construction have proven their outstanding filtration properties, thanks to which they can effectively separate fine dust and at the same time have a low pressure loss, which is reflected in lower consumption and overall quieter operation of the ventilation system. The use of these filters is certainly noticeable in the significantly longer lifespan of the entire system. So if you want to take your ventilation system to a new level, test our RUKATECH SafeLuft filters.