What are air filtration systems for ventilation and which components do they include

Air filtration systems for ventilation consist of air filters, cassette filters, filter boxes and sealing elements that clean supply or extract air in ventilation systems. They are installed in air handling units (AHU), rooftop units and ductwork to protect equipment and occupants from dust, pollen, soot and other contaminants.

How are these systems different from standalone air purifiers?

Standalone air purifiers work locally in a single room and are not connected to the building’s ventilation ducts. Air filtration systems for ventilation are integrated into the central ventilation system and are designed for higher airflows, industrial/commercial conditions and specified filtration classes according to the ventilation design.

In which buildings and systems are cassette filters and filter boxes typically used?

Cassette filters and ventilation filter boxes are used in office buildings, shopping centres, warehouses, logistics hubs, industrial plants and other commercial buildings. They are installed in air handling units or ductwork to provide the required level of air filtration for entire zones, floors or buildings.

What is the difference between cassette filters and filter boxes in ventilation systems

A cassette filter is a replaceable filter element that provides a specific filtration class. A filter box is a metal housing installed in the ductwork or connected directly to the AHU, into which cassette or panel filters are inserted. Filter boxes are especially useful when an additional filtration stage is needed for a specific branch or when there is not enough space inside the unit itself.

Which filter classes are used in ventilation and how do I choose the right one?

Ventilation filters are divided into coarse, medium and fine filtration classes according to current standards (for example ePM10, ePM2.5, ePM1). For storage areas and technical rooms coarse and medium filters are often sufficient, while offices, retail areas and sensitive industrial processes require higher filter classes. The choice is based on the project requirements, outdoor air quality and the building’s use.

How often should ventilation filters and cassette filters be replaced?

Replacement intervals depend on outdoor air quality, operating hours and filter class, but in most commercial and industrial buildings filters are changed every 3–6 months, sometimes once per year in cleaner environments. In addition to the calendar, pressure drop across the filter and visual inspection should always be monitored.

How does a clogged air filter affect energy consumption and system performance?

A clogged filter increases pressure drop in the system, which means the fan must work harder to deliver the same airflow. This leads to higher energy consumption, reduced airflow in the rooms and additional stress on the equipment. Regular filter replacement reduces energy use and keeps the ventilation system within its design parameters.

When does it make sense to use filter boxes in ductwork in addition to filters in the AHU?

Filter boxes are used when an extra filtration stage is needed close to a specific zone (for example clean areas, laboratories, offices with higher requirements) or when an existing ventilation system must be upgraded without replacing the air handling unit. They allow you to add or improve filtration on selected branches of the ductwork.

Can our maintenance staff replace filters themselves, or should we use a professional service provider?

Basic filter replacement can often be carried out by on-site maintenance staff, provided they follow safety rules and the manufacturer’s instructions. For larger industrial and multi-zone systems, we recommend using professional service teams who can check filter classes, pressure drop, sealing and the overall condition of air filtration systems at the same time.

In which regions do you supply cassette filters, filter boxes and air filtration components, and how is pricing determined?

Our main market is Estonia, and we also supply cassette filters, filter boxes and other ventilation filtration components to Latvia and Lithuania. Pricing depends on the filtration class, dimensions, housing type, materials and order volume. For projects we prepare individual quotations, taking into account technical requirements and logistics in the Baltic region.

Filter Boxes – Buy in Estonia I EU-Wide Delivery

When selecting air filtration systems for residential and industrial applications, it is essential to consider the required air cleanliness level, the types of pollutants and the operating regime of the ventilation system. A well-chosen combination of filters and filter boxes provides the necessary air quality without excessive energy consumption or overly frequent filter replacement.

What we consider when selecting:

Purpose of the building and zone — residential areas, offices, storage spaces, production and process zones require different filtration levels.
Types of contaminants — common dust, construction particles, fibres, aerosols or process emissions determine the choice of filter class and type.
Required filtration class — solutions are selected in line with project specifications and air quality standards (coarse, medium or fine filtration).
Allowable pressure drop — the resistance of air filtration systems is calculated with regard to fan capacity and duct lengths.
Operating mode and service access — we assess how easy it will be to replace filters under continuous or seasonal operation and define realistic service intervals.
Budget and total cost of ownership — filters are selected with an optimal balance between price, lifetime and replacement frequency.

Filter boxes

Air filtration systems for residential and industrial applications

Key benefits of air filtration systems for residential and industrial applications

How air filtration systems work in ventilation units and ductwork

How to select air filtration systems for residential and industrial applications

Frequently asked questions about cassette filters and filter boxes