V. Replacing the Dust-cup
1. When the dust reaches to the yellow board level in the dust-cup, it means
dust-cup is full. At this moment, dust-cup should be emptied or the HEPA-filter
should be replaced.
2. Open the dust-cup as showing in the picture.
VI. Maintenance
1. The HEPA-filter should often be washed when it is dirty and suggest to be
replaced after using 100 hours or so in order to avoid barrier.
