Wet / Dry Canister Vacuum Cleaners: are the most versatile type of vacuum cleaning system that can be put to use in any building services maintenance program. These vacuum cleaners can be used for a wide variety of cleaning jobs including vacuuming of furnishings and carpets, removing spill and floor scrubbing solutions, cleaning soot from boilers and furnaces, dusting of overhead pipes and for dozens of other general cleaning tasks required in most buildings on a frequent basis.
A wet / dry canister vacuum cleaner consists of five basic components:
- Power Head
- Cleaning Attachment
The power head of a wet / dry vacuum cleaner sits on top of the canister and contains a vacuum motor assembly of either a by-pass or an open-face fan type. A wet/dry vacuum cleaner containing a by-pass type motor assembly has a high average compromise ratio of both airflow and suction. As a result, this style of wet/dry vacuum cleaner has a broader range of cleaning applications than the open fan face style and utilizes an internal filter bag.
A wet / dry vacuum cleaner containing an open face fan type of motor assembly has a relatively higher airflow rating and a slightly lower suction rating than the by-pass style of wet/dry vacuum cleaner, and utilizes an external filter bag. An automatic “float shut off” mechanism is fastened to the underside of most wet/dry power heads. The automatic “float shut off” mechanism serves as a means of protecting the vacuum motor assembly within the power head from any liquids entering its air intake during wet cleaning operations. When the fluid level in the canister climbs to a predetermined height, the float of the mechanism, rises to stop the vacuum cleaning operation. The float within the mechanism generally rises to simply block off the air intake of the vacuum motor before any liquids can enter and cause harm to the internal parts of the vacuum motor assembly.
At the moment, the sound emitted from the vacuum motor rises in pitch, and a loss of suction is felt at the cleaning attachment, notifying the operator to empty the canister. Other designs of automatic float shut off mechanisms, rise to actuate a waterproof electrical switch, cancelling the power supplied to the vacuum motor assembly. All automatic float shut-off mechanisms should be checked for freedom of movement before being used for wet pick-up tasks.
Wet / Dry canister vacuum cleaners utilizing an internal filter bag for dry soil filtration, must have the filter bag removed, before attempting to use the vacuum cleaner for any wet soil removal tasks. The reason being that any liquids contacting the filter bag, being made of a cotton material, would damage the filter bag by shrinking the filter material causing its small pores to constrict, and thereby hinder its filtration abilities and interfere with the system’s airflow. Special filter bags made of loose weave synthetic material are available for certain wet pick-up applications. These filter bags are used when working with high foaming cleaning solutions for keeping harmful foam and lint from entering the vacuum rotor assembly.
Canisters are the main body of wet/dry vacuum cleaners and are available in varying sizes from one to sixteen gallon capacities. They are constructed of either steel, polypropelene or stainless steel. Those constructed of steel are the least expensive, but tend to rust and dent easily. The formation of rust is greatly accelerated when the canister is used for pick-up of corrosive solutions.
Canisters constructed of polypropylene material are most desirable and will not rust or dent easily. They are also light weight and their translucent quality allows the operator to see the fluid level through the canister. Polypropylene canisters have no seams so they are easy to clean and are most popular with hospitals because of this.
Canisters constructed of stainless steel are most widely used. Stainless steel is durable, rust proof and looks most attractive. Some of the larger canisters have a “swivel tilt” feature which allows the operator to dump the contents of the canister with less physical exertion.
The wet / dry vacuum cleaner hose is a spiral hose made of polyethylene and is most commonly of a one and a half inches in a diameter. Friction cuffs made of flexible plastic have inner threads which screw over top of the ends of the spiral polyethylene hose. These cuffs are to be slipped over the cleaning attachments.
The cleaning attachments which may be used are illustrated under ‘Vacuum Cleaning Attachments’
Canister Type Vacuum Cleaner Pre-Inspection
- Inspect canister and filters are clean.
- Check proper filter for intended use. (wet/dry)
- Inspect electrical cord and plug.
- Plug unit in and check power and suction
- Check operation of safety float.
- Inspect attachments.
Care for Canister Type Vacuum Cleaner After Use
- Empty canister, clean and wipe out.
- Wipe and coil electrical cord
- If used for wet pick-up run motor off unit to dry. (only if flooded)
- Place power head on its side on top of the canister.
- Clean attachments.
- Store properly.