Case Share from Lifa Director Mr. Apollo Kwok!

1) The filter bags photos showed that the filter bag after 1.5 years usage turned black in colour (white colour one is new filter bag), but you cannot find big size dust on the filter surface as the HVAC system already have pre-filter. THAT FINE PARTICLES IN BLACK COLOUR ARE IN-HALED IN YOUR LUNG!

2) From the photo taken at the case, you can easily noticed that the filter box right after the 3G filter bag is very clean. That means the filter is still functioning even the filter surface turned in black colour!