This G4 filter is for the Eco300. This is an excellent machine and all parts if needed are available from ourselves.
The three standard types of filters are:
G4 – coarse filter
F7 – fine filter
The finer the filter, the more and smaller particles it will filter from the air. However, a finer filter means that the ventilation system has to work harder to transport air through the system.
That means you should not choose a finer filter than you need.
Exhaust air does not need more than a G4 filter, since the air indoors has already been cleaned once, which is enough to keep the ventilation system’s inner workings clean.
You should choose either a G4 or F7 for intake air. So, what is the difference ?
G4 only removes dust particles that are big enough to be seen with the naked eye. A finer filter that also filters out smaller particles would probably be a better choice for most households. For example, pollen, asphalt particles and smoke from wood stoves that you would rather not let into the house.
If you need to filter the air even more, perhaps due to allergies, you can choose an F7 filter instead. You can also particularly order even finer filters.