In winter, outdoor air becomes very dry once it is heated indoors, and mechanical ventilation often reduces indoor relative humidity to 20–30 RH or even lower. This article explains why this happens, how different heat exchanger types (plate, condensation rotor, enthalpy, sorption) affect indoor moisture balance, and what you can do in practice. We cover smart ventilation control during cold nights, protection against excessive drying, when a humidifier is really needed, and simple ways to increase or reduce humidity naturally. You will also find an FAQ with common real-life situations and climate-specific recommendations for different countries.
Cold outdoor air and warm, humid extract air can create condensation that may freeze inside the heat exchanger. Learn what “defrost” does, why airflow balance matters, and how to reduce frequent frost cycles.
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.
Cold and flu season often starts indoors — not outside. While filters in your ventilation unit can’t trap viruses themselves, proper air exchange, high-efficiency filters and balanced humidity greatly reduce the risk of infection and keep your home air cleaner and healthier.
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.
During the heating season, outdoor air quality across Europe often deteriorates due to increased combustion and vehicle emissions. CleanFilter introduces new activated carbon filters designed for heat recovery units – an effective way to remove odors, smog, and harmful gases from the air supplied to your home.
Did you know that an incorrectly installed filter can cut your heat recovery unit’s lifespan in half? Learn which mistakes to avoid and how to replace your filters correctly at home.
Autumn is the perfect time to check your indoor air quality. HVAC installers share expert tips on choosing the right filters for your MVHR system. Learn when to use G4, M5 or F7 filters, when activated carbon filters are worth it, and how proper maintenance helps your unit last longer.
As the heating season begins, make sure your ventilation unit (air handling unit) is working efficiently and delivering clean, fresh air throughout your home. Check the filters, airflow, heat exchanger, and condensate drain to prevent unpleasant odours and system faults. A well-maintained unit saves energy and ensures a healthy indoor climate all winter long.
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.