Air Filter Replacement — Clean Air with the Right Filters

Air filters are the ventilation system's first line of defense against outdoor air contaminants. Filters prevent dust, pollen, fine particles, and other harmful substances from entering the indoor air. When a filter becomes saturated, it no longer allows sufficient air to pass through, and its filtration capacity decreases significantly.

The consequences of a clogged filter are numerous:

• Reduced ventilation: Air does not circulate sufficiently, raising carbon dioxide concentration and humidity
• Increased energy consumption: The air handling unit must run at higher power, consuming more electricity
• Poorer indoor air: An overloaded filter allows more contaminants to pass through
• Unit strain: Continuous overloading shortens the lifespan of the fans and motor

Ventilation filters are classified according to their filtration capacity. Choosing the correct filter grade is important for both air quality and ventilation performance:

• G3–G4 (coarse filter): Basic filtration, filters most dust and pollen. Commonly used as an exhaust air filter
• M5 (medium filter): A good general-purpose filter for the supply air side. Effectively filters dust and pollen
• F7 (fine filter): An effective filter that also captures fine particles. The recommended supply air filter for allergy sufferers
• F9 and HEPA: Very high-efficiency filtration, used in special applications and for highly sensitive allergy sufferers

In a typical household air handling unit, an F7-grade filter is used on the supply air side and an M5 or G4-grade filter on the exhaust air side. A higher-grade filter provides better filtration but also increases airflow resistance.

The optimal filter replacement interval depends on several factors. Generally recommended intervals are:

• 6 months: In urban areas, near busy roads, or in dusty environments
• 12 months: Under normal conditions, in rural environments
• 3 to 6 months: During pollen season in spring and early summer, if household members have allergies

The need for filter replacement is easy to identify from a few signs:

• The air handling unit runs louder than normal
• Indoor air feels stuffy and airflow from the valves is reduced
• The air handling unit display indicates a filter change is needed
• The filter is visibly dirty when inspected

Filters should be checked at least every 3 months and replaced whenever they are clearly dirty.

Finding the right filter is important for proper ventilation operation. An incorrectly sized or typed filter can cause problems such as air leaks past the filter or excessive pressure drop.

When selecting a filter, consider the following:

• Unit make and model: Each air handling unit requires a specific filter size. The correct size can be found in the unit's user manual or service logbook
• Filter grade: Choose at least the same filter grade as the original filter. For allergy sufferers, an F7-grade supply air filter is recommended
• Filter type: Cassette, bag, or panel filter according to the unit model

We are happy to help with choosing the right filter. We deliver filters directly to your home and replace them during the same visit. You can also arrange a regular filter replacement service, where we take care of filter changes automatically at agreed intervals.

Air filter replacement is an affordable way to maintain good indoor air quality. Filter prices vary by unit model and filter grade:

• Filter set (supply + exhaust): 30 to 80 euros depending on material and size
• Replacement labor: 50 to 100 euros including the visit
• Filter set + replacement total: from 80 euros

Regular filter replacement is one of the most affordable ways to take care of your home's air quality. A clogged filter increases the air handling unit's electricity consumption and shortens its lifespan, so neglecting filter replacement becomes more expensive in the long run.

We also offer annual maintenance contracts that include filter replacement 1 to 2 times per year along with a basic unit check. Contract pricing makes maintenance more affordable than individual service visits.