Not all ventilation unit filters are the same. Some ensure clean, healthy indoor air, while cheaper or uncertified filters can pose risks to both the ventilation system and your health. This guide explains what to look for when choosing filters — from ISO 16890 testing and hygiene standards to material safety and real filtration performance — so you can be confident you’re using a safe, certified and reliable filter.

Foggy windows, high humidity or mold in homes with an AHU or MVHR system? Learn why this happens and how to fix it – from airflow adjustments to filter checks.

Manufacturers recommend changing them every 6 months under normal conditions, or every 4 months in polluted areas. Learn the key signs that your filter is clogged and how to choose the right replacement interval.

Coarse filters capture larger particles like dust and sand while ensuring low airflow resistance, quieter operation, and energy efficiency. Ideal for ventilation systems, they extend filter lifespan and protect HVAC components. CleanFilter Coarse filters offer premium materials, high dust-holding capacity, and certified performance for cleaner indoor air.

G4 filters are effective at trapping medium-sized dust particles, sand, insects, lint, and even some larger pollen particles. They provide sufficient filtration to keep ventilation systems running smoothly and cleanly.

Knowing the difference of the filtration classes according to the ISO 16890 may help you select the necessary filters according to your needs 

Original filters aren’t always better. Most ventilation unit (AHU) brands buy filters from specialized manufacturers, so “original” often means a label rather than superior quality. What matters is proven performance to ISO 16890, high-quality PFAS-free filter media from Sandler AG, VDI 6022 hygiene compliance, airtight construction, and clear EU origin. CleanFilter analogue filters often match or outperform originals, cost 2–3 times less, and are used as “original” filters by several manufacturers.

Many people who change filters for the first time are often surprised to learn that a recuperator needs 2 filters - after all, it needs to filter the air from outside, doesn't it?

Replacing filters in your air handling unit (AHU) is a simple yet crucial task for maintaining system efficiency and air quality. This guide walks you through the correct steps, from selecting the right filter class to ensuring proper airflow direction and resetting the filter timer. Follow these easy steps to keep your ventilation system running smoothly and avoid unnecessary issues.

Choosing the right filter for your air handling unit (AHU) can be overwhelming with so many options available. Whether you have a SALDA, Komfovent, Systemair, Flexit, or Wolf AHU, understanding the key factors such as air quality, filter class, and manufacturer specifications is essential. This guide outlines the basic rules for selecting the appropriate filter to maintain your system’s performance and avoid potential warranty issues.