In order to maintain the proper function of a ventilation system, it is important to check and service all of the filters regularly. Some filters can be cleaned with a vacuum cleaner, especially when it is only dust or insects that have been captured. Cellulose based filters should not be washed.
It is recommended to check filters every 3-6 months, depending on the use of the system, the environmental pollution and the dust load. When a filter has got a continuous layer of dust, it is high time to get them cleaned or changed. Once a year all filters should be replaced, in order to avoid any growth on the filter medium. Keep in mind, that the dust that is trapped in the filters, is dust that did not enter your dwelling.
Most of our modern systems are volume flow constant, which means that they maintain the same airflow and keep balanced, even when filters start to clog up. When the filters are very soiled, the system will become louder, as the fans have to compensate for the increased resistance. Keeping the filters clean will help to keep the system silent and to maintain a low energy usage.
What filters should be used for a MVHR system?
- Extract (within the MVHR unit): Typically a coarse dust filter of G4 grade is being used.
- Intake (within the MVHR unit): G4 filters or M5/ F5 filters are supplied as standard, but it is generally recommended to use a finer filter of F7 grade, also called pollen filter. These help to keep the supply ductwork clean, as they filter finer dust and particles and bacteria and spores out of the incoming air. PAUL now offeres new F7 filters, which have better air flow properties and can be more easily cleaned.
- Intake pre-filter (e.g. in a defrost pre-heater box): Typically a dust filter of G3 grade is being used.
- For areas of high traffic pollution, we can provide a NOx filterbox for the supply air, which has an active charcoal filter for binding dangerous NOx gases.
- Kitchen extract (in the room extract point): Typically a dust & grease filter of G3 grade is being used.
Traffic fumes or rural smells can be absorbed with active charcoal filters. These can be placed in an ISO filter box, which is inserted into intake duct run (from the outside to the MVHR).