@DavidElfstrom Filter on outlet has the disadvantage of the fan getting dirty. I might also put a very light dust filter (cloth or open cell foam) on the inlet.
@出口处的DavidElfstrom过滤器存在风扇变脏的缺点。我也可以在进气口放一个非常轻的灰尘过滤器（布或开孔泡沫）。
@DavidElfstrom Filter on outlet has the disadvantage of the fan getting dirty. I might also put a very light dust filter (cloth or open cell foam) on the inlet.
@出口处的DavidElfstrom过滤器存在风扇变脏的缺点。我也可以在进气口放一个非常轻的灰尘过滤器（布或开孔泡沫）。