I'll teach you guys how to save more with the AX40.
Every year, the haze months run for about 4 months. You can use 1 x original HEPA for 8 months hazy periods, so that's 2 years lifespan per original HEPA filter.
Non hazy period of 8 months, you can use this Taobao filter. Don't have to customise (so no need to type in Chinese to converse with the seller), just trim the part that runs along the pleat. Then the top part can just roll up the plastic packaging and plug the gap. It would work, trust me, I have measured.
Same, 4 months for the filter. So 1 year use 2pc.
RMB 29.90 per piece. Just buy 6 or 8 in 1 shot ba.
This would drop the airflow by about 35% max (it's more like 30% actually, actual measurement with my anemometer). So it becomes 210 m3/hr. It would also be slightly more silent, and suck less electricity due to slower motor rotation with the added resistance (as measured current draw with a multimeter). 210m3/hr is good for 14.5m2 room with 5 ACH, shd be just nice for MBR during non hazy months.
http://world.taobao.com/item/412171...&spm=a312a.7700824.w4004-8871129750.35.4ePHOj