Do not place vacuums on book trucks to raise them off the floor. This is especially important for the HEPA vacuums which burn out when the filters are not changed in time. Replacement motors are very expensive. For dry vacuuming only. The filter bag should be changed when half full or when suction notably decreases.
Fine dust is more likely than chunks of debris to clog filter pores and block air circulation.
The result is an overheated motor that burns out. If a strong smell is noticed, turn the vacuum off immediately and contact the Preservation Department. After the filter bag has been changed 10-12 times, the corrugated HEPA filter will also be changed. Please monitor HEPA use to ensure that the filters are changed on a regular basis. This will ensure a longer machine life and more effective cleaning.