Central vacuum cleaner

Inlets are installed in walls throughout the building that attach to power hoses and other central vacuum accessories to remove dust, particles, and small debris from interior rooms.

Early steam-powered vacuum cleaners were mounted in a heavy carriage equipped with a long hose so they could be moved from one location to another, providing a specialized cleaning service by appointment.

Stationary-powered vacuum cleaners were built-in and centralized, due to the large and heavy machinery needed to produce the required airflow.

Previously, more expensive metal tubing was used exclusively (and it may still be used for part or all of an installation, if required by building fire code regulations).

Sometimes, the higher suction power of the central vacuum may require reduction (for example, when cleaning a delicate sheer fabric curtain).

Excess suction is "bled off" by partially opening a bleed port or slot to let some intake air bypass the cleaning tool.

[4] True cyclonic cleaners do not use filtration bags, instead separating the dirt and dust into a detachable cylindrical collection vessel or bin.

Roughly speaking, the dust particles and other debris spiral outward to the wall of the vessel by centrifugal force, where they fall due to gravity into the bottom of the collection bin.

A well-designed cyclonic separation system does not lose suction power due to airflow restriction until the collection vessel is almost full.

In a portable vacuum, if the filter bag fails, this condition becomes immediately obvious as a cloud of dust and dirt blows into the room.

True cyclonic systems are very effective in removing all but the finest particles, which are then exhausted directly outside, eliminating the need for replaceable filters and their consequent airflow restrictions.

The air-driven (or turbine) systems are frequently less expensive since they do not require electrical wires for power to be run to each wall inlet.

Many users find that the high suction of central vacuums is more than sufficient by itself for most casual cleaning jobs, but reserve a powered brush tool for more difficult tasks.

Successful installation of such systems requires special fittings, and careful design and workmanship, to ensure smooth hose retraction into the piping for storage.

Automatic dustpans (e.g. "Vacpan" or "KickSweep") can be installed in the kickspace under a kitchen, bathroom, or workroom countertop, enabling a person to use a standard broom to sweep debris directly into a vacuum inlet located there.

[4][7][8] Alternatively, a "DrawerVac" inlet which pulls out like a drawer from the underside of a table or counter can be used to dispose of debris from a shop or kitchen work surface.

[12][10] This initial expense must be weighed against the long-term benefits of a central vacuum, including the typical longer service life of the equipment, and negligible consumables cost if a filterless system is chosen.

[12][4][10][11] Central vacuum systems require periodic emptying of the dirt canister or replacing the filter bag, typically 2–4 times per year.

For filtered systems, the bag may need to be replaced long before it is filled to its nominal capacity, because of reduced suction due to clogging with dirt or fine dust.

Filterless cyclonic separation systems only require emptying the dirt collection container before the suction drops off as an almost-full condition is reached.

Regardless of which dirt separation system is used, the electric motor may require lubrication of its bearings, or replacement of carbon brushes on an infrequent basis, usually measured in years.

[14] A homeowner can usually use simple tools and techniques to locate and remove the obstruction,[15] or can hire a professional vacuum installer to do repairs.

[16] A principal concern when designing a central vacuum system is avoiding situations likely to cause clogging of the piping with debris such as toothpicks, hairpins, needles, or similar-shaped objects.

In new construction, the vacuum piping is usually installed during a "rough-in" phase once the building interior framing is complete, after other in-wall utilities (e.g. plumbing, HVAC, electrical, etc.

Installing a central vacuum early in the project makes ongoing cleanup much easier, especially if it is a filterless true cyclonic unit, which can inhale even abrasive or sharp construction debris without concerns about bag clogging or breakage.

A non-stretchable cord of appropriate length (or a thin wire on an architectural scale drawing) can be used to check for the adequate reach of a vacuum hose.

In some jurisdictions, fire code regulations require that an intumescent firestop collar be installed around the pipe when it penetrates a firewall.

[5] For years, HP Vacuflo advocated the slightly smaller 1+13⁄16-inch (4.6 cm) piping size (outside diameter), claiming that their studies showed that it was less likely to clog.

Occasionally, the owner of a new house under construction may choose to preinstall vacuum piping and control wiring in the walls but defer the purchase of the central unit, hose, and tools to reduce cash flow requirements.