![Drainvac central vacuum with air inlet](https://upload.wikimedia.org/wikipedia/commons/6/60/Drainvac_central_vacuum_with_air_inlet.jpg)
![Conduit d'aspirateur - Château Dufresne](https://upload.wikimedia.org/wikipedia/commons/8/85/Conduit_d%27aspirateur_-_Ch%C3%A2teau_Dufresne.JPG)
![Central vacuum system](https://upload.wikimedia.org/wikipedia/commons/b/bf/Central_vacuum_system.jpg)
A central vacuum cleaner (also known as built-in or ducted) is a type of
vacuum cleaner
A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven.
The dirt is collected by either a ...
appliance, installed into a building as a semi-permanent fixture. Central vacuum systems are designed to remove dirt and debris from homes and buildings, sending dirt particles through piping installed inside the walls to a collection container in a remote utility space. The power unit is a permanent fixture, usually installed in a basement, garage, or storage room, along with the collection container. 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. Most power hoses usually have a power switch located on the handle.
History
19th century
The first introduction of a system similar to a central vacuum cleaner was in the late 19th century. A ducted machine that featured copper tubes connected from a
bellows
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtigh ...
chamber, typically located in the basement, and extended to several locations throughout a building, was used in a select few homes at this time. Because of the machine’s cost and weak dust-removal capabilities, only a few of these units were ever sold in the United States.
In 1869 Ives McGaffey patented the first portable vacuum cleaner, or “sweeping machine”. The portable
vacuum cleaner
A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven.
The dirt is collected by either a ...
is the parent product to the modern central vacuum system.
20th century
In the 1930s, the development of small, powerful
electric motors
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force ...
increased the popularity and availability of the portable vacuum cleaner, and further diverted consumers from purchasing central cleaners.
By the early 1960s, the invention of
polyvinyl chloride (PVC) made the central vacuum system more affordable in North America by using PVC extrusion pipe instead of metal tubing for the piping system inside the walls. 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
Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent the ignition of an uncontrolled fire and those that are used to limit the development and eff ...
regulations.
In the 1990s, central vacuum systems gained popularity among
real estate agent
A real estate agent or real estate broker is a person who represents sellers or buyers of real estate or real property. While a broker may work independently, an agent usually works under a licensed broker to represent clients. Brokers and agen ...
s and
home remodelers for the value they added to homes at resale. Allergists also played an important role in the growing popularity of central vacuum systems in the 1990s.
Health Benefits
With central vacuum systems that exhaust completely out of the home, no dust or allergens are recirculated through the interior air, as is the case with a traditional vacuum.
A 2001 study at
University of California at Davis
The University of California, Davis (UC Davis, UCD, or Davis) is a public land-grant research university near Davis, California. Named a Public Ivy, it is the northernmost of the ten campuses of the University of California system. The institut ...
showed improvements in multiple aspects of health in 25 individuals with a documented history of type I
hypersensitivity
Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune s ...
to
house dust
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...
. Each of these individuals used either a Beam Central Vacuum System or their own conventional vacuum for a period of three months. At the end of this period, the individual switched over to the opposite limb of the study for three additional months. In all seven domains of the evaluation, including activity, sleep, non-nasal symptoms, practical problems, nasal symptoms, eye symptoms and emotions, use of the central vacuum proved to be superior.
Central vacuum installations can earn points for
Leadership in Energy and Environmental Design
Leadership in Energy and Environmental Design (LEED) is a
green building certification program used worldwide. Developed by the non-profit U.S. Green Building Council (USGBC), it includes a set of rating systems for the design, construction ...
(LEED) home certification, Health House certification by the
American Lung Association
The American Lung Association is a voluntary health organization whose mission is to save lives by improving lung health and preventing lung disease through education, advocacy and research.
History
The organization was founded in 1904 to figh ...
, or the National Green Building Standard of the
National Association of Homebuilders (NAHB).
Power
The suction power of a vacuum cleaner is calculated in
airwatts (or air watts) ̶̶ not to be confused with
watt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wa ...
s, which only refers to electrical power. The airwatt value relates between the airflow, the waterlift and power consumption. This datum is calculated as follows: P = 1/8.5 x F x S where P translates to the power in airwatts; F is the airflow in CFM; and S for the waterlift. The standard airwatt formula is from
ASTM International
ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, an ...
(see document ASTM F558 - 13).
The airwatts indicate the motor's global performance, and thus the central vacuum's efficiency level.
Nowadays, the power of single motor central vacuums is usually between 500 and 800 airwatts. For central vacuums that operate with two motors, the best practice for representing the vacuum cleaner power is to add "2 X" in front of the power for one motor. For instance, if a central vacuum has two motors with a power of 500 airwatts each, the whole central vacuum has 2 X 500 airwatts. It is important to note that airwatts cannot be added together: a unit with two motors of 500 airwatts each does not make a 1000-airwatt unit.
For central vacuums with two motors, these may be connected in series or in parallel. When two motors are connected to each other in series, both motors work together so that the air outlet of the first one is the air inlet of the second one. This configuration gives more waterlift (calculated in H₂O or mmH₂O). Waterlift indicates the maximum suction force (pressure) of the device when the hose opening is blocked. The higher the value, the heavier objects or dense materials can be easily vacuumed. A high suction force is usually required for deep carpet cleaning or for vacuuming liquids. If two motors are set up in parallel, both motors work independently. Each of them takes their air from the same canister but have their own air inlet and air outlet. This configuration generates more airflow (calculated in CFM or m³/h). Airflow indicates the amount of air vacuumed per minute or per hour with a fully opened hose. The higher the value, the greater the cleaning area is covered by the device. A bigger airflow is preferable to clean hard-surfaced floors to reach dust as far as possible.
Operation
To use a central vacuum, the vacuum hose is removed from storage and fitted with any needed cleaning accessories (such as a brush). The other end of the hose is inserted into a wall-mounted vacuum inlet, after opening the spring-loaded cover door.
In some designs, opening the door switches on the vacuum motor; in other designs, insertion of the metallic hose-end fitting bridges two electrical contacts, signaling the motor to turn on. Other alternative designs feature a remote on/off switch located at the tool end of the vacuum hose, which communicates either via a pair of wires embedded in the hose, or via
wireless
Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ...
signaling.
![Central Vacuum Inlet](https://upload.wikimedia.org/wikipedia/commons/3/34/Central_Vacuum_Inlet.jpg)
Vacuuming is performed in the same manner as with a portable machine. Sometimes, the higher vacuum power of central vacuum may require reduction (for example, when cleaning a delicate
sheer fabric
Sheer fabric is fabric which is made using thin thread or low density of knit. This results in a semi-transparent and flimsy cloth. Some fabrics become transparent when wet.
Overview
The sheerness of a fabric is expressed as a numerical denier ...
curtain). Excess vacuum is "bled off" by partially opening a bleed port or slot to let some intake air bypass the cleaning tool. The bleed port is usually located at the tool end of the vacuum hose, to allow quick adjustment during use.
When cleaning is complete, the vacuum hose is removed from the wall inlet (which snaps shut and shuts down the vacuum motor). The hose is coiled up and hung on a storage rack, and any cleaning accessories are stowed away.
Dirt Separation
![Centraldammsugare](https://upload.wikimedia.org/wikipedia/commons/2/25/Centraldammsugare.jpg)
Cyclonic and filtered central vacuum systems are the two main types of central vacuums, differentiated by the method used to separate dirt and dust from the incoming airstream.
True
cyclonic
In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anti ...
cleaners do not use filtration bags, instead separating the dirt and dust into a detachable cylindrical collection vessel or bin. Air and dust are sucked at high speed into the collection vessel at a direction
tangent
In geometry, the tangent line (or simply tangent) to a plane curve at a given point is the straight line that "just touches" the curve at that point. Leibniz defined it as the line through a pair of infinitely close points on the curve. More ...
ial to the vessel wall, creating a fast-spinning
vortex
In fluid dynamics, a vortex ( : vortices or vortexes) is a region in a fluid in which the flow revolves around an axis line, which may be straight or curved. Vortices form in stirred fluids, and may be observed in smoke rings, whirlpools in th ...
. Roughly speaking, the dust particles and other debris spiral outward to the wall of the vessel by
centrifugal force
In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is paralle ...
, where they fall due to
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
into the bottom of the collection bin. For a more complete technical description of this process, see the article on "
Cyclonic separation
Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone ...
".
In fixed-installation central vacuum cleaners, the cleaned air may be exhausted directly outside without need for further filtration. A well-designed cyclonic separation system does not lose
suction power Airwatt or air watt is a measurement unit of the effectiveness of vacuum cleaners which refers to airflow and the amount of power (watts) a vacuum cleaner produces and uses.
It can also be referred to as a measurement of the energy per unit time of ...
due to airflow restriction until the collection vessel is almost full. This is in marked contrast to filter bag systems, which gradually lose suction as pores in the filter become clogged by collected dirt and dust.
Filtered systems use a wide variety of different bags or filters that must be cleaned (permanent cloth bags) or replaced (disposable paper bags) on a regular basis. Filters can be made from screening, foam, paper, or cloth, and are usually proprietary designs that may not be widely available. Over time, repeated purchase of filters and bags can become significant ongoing expenses.
Bag breakage is an issue that arises with filtered central vacuums. 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. Although it creates a mess, at least the problem can be immediately brought under control by shutting off the appliance. By contrast, if the filter bag in a central unit should fail, little change may be noticed by the remote operator. In fact, the only perceivable change may be an ''increase'' in suction power as a clogged but broken bag is completely bypassed. If the filtered air is also used to cool the motor (a very typical design), the first clue that something is amiss may be when the motor completely
seizes up due to dirt accumulating in the motor brushes, windings, or bearings. Such a failure can require complete replacement of the expensive central unit.
Filterless central vacuums are completely immune to such failures. In addition, the best designs in either system incorporate so-called "bypass cooling", using a completely separate source of ambient air to cool the motor, rather than the design expedient of using just-filtered dirty airflow for this vital function.
Hybrid cyclonic filtered systems have been made, which use a rudimentary cyclonic motion to separate out larger dirt particles, but rely on conventional filter bags to trap remaining finer particles. True cyclonic systems are very effective in removing all but the finest particles, which are then exhausted directly outside, completely eliminating the need for replaceable filters and their consequent airflow restrictions.
The exhaust from a good quality true cyclonic system does not contain any visible large particles, and contains far less debris than a typical
clothes dryer
A clothes dryer, also known as tumble dryer or simply dryer, is a powered household appliance that is used to remove moisture from a load of clothing, bedding and other textiles, usually shortly after they are washed in a washing machine.
Many dry ...
exhaust.
Tools and Accessories
![Zentralstaubsaugerrohr](https://upload.wikimedia.org/wikipedia/commons/a/ab/Zentralstaubsaugerrohr.jpg)
Central vacuums can be equipped with either an electrical power brush or an air-driven power brush. The air-driven (or
turbine
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating e ...
) systems are frequently less expensive since they do not require electrical wires for power to be run to each wall inlet. Turbine-driven brushes tend to be louder than electric brushes; the noise from either is more noticeable in the absence of the "vacuum whine" produced by a portable vacuum. 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.
The average standard central vacuum system is equipped with a 30 foot (9 m) hose, plus standard cleaning tools similar to those used with portable vacuum cleaners. For further convenience, some owners will keep a hose and set of tools on each floor of a multi-story building. When not in use, the hose is loosely coiled around a wire rack mounted on a closet wall, or on the back of a door.
An alternative for storing vacuum hose is the "Hide-A-Hose" system, which uses suction to draw the hose into the vacuum piping in the wall for storage. Hose lengths used are typically 30/40/50 ft (9/12/15 m). Successful installation of such systems requires special fittings, and careful design and workmanship, to ensure smooth hose retraction into the piping for storage.
A scaled-down 10-foot (3 m) version (such as "Spot by Vroom") is available for quick cleaning in locations such as mud rooms and laundry rooms. The original "Vroom" system, which is still available, uses suction to operate a cabinet-mounted hose reel with a 24 ft (7.3 m) hose, rather than storing the hose within the wall piping.
A modular vacuum hose called "QuickClick" is available in 10/15/20 foot (3/4.5/6 m) lengths, allowing a custom-length hose to be quickly set up or taken apart by an end user. In addition, a promotional article in a trade magazine says that
arthritic
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In some ...
testers were able to connect and disconnect the hose in spite of their disability.
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
A broom (also known in some forms as a broomstick) is a cleaning tool consisting of usually stiff fibers (often made of materials such as plastic, hair, or corn husks) attached to, and roughly parallel to, a cylindrical handle, the broomstick. I ...
to sweep debris directly into a vacuum inlet located there.
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.
The "VacnSeal" is an accessory intended to be installed on the underside of a
kitchen cabinet
Kitchen cabinets are the built-in furniture installed in many kitchens for storage of food, cooking equipment, and often Silver (household), silverware and Dishware, dishes for table service. Home appliance, Appliances such as refrigerators, dish ...
, over a countertop used for food preparation. The nozzle of the device is used to evacuate excess air from a
zipper lock plastic food storage bag (e.g. Ziploc), which is said by the manufacturer to preserve food freshness for a longer period of time.
Advantages
![Avløpsventil for sentralstøvsuger](https://upload.wikimedia.org/wikipedia/commons/a/ae/Avl%C3%B8psventil_for_sentralst%C3%B8vsuger.jpg)
* Increased suction power — Because the vacuum cleaner motor and dirt collection system need not be portable, the weight and size of the unit are not as severely limited compared to a portable system; some units even use two motors for extra power.
In addition, bagless filterless systems avoid the inevitable loss of suction in filtered systems caused by collected dust clogging the filters.
* Ability to handle "difficult" debris — Central vacuums, especially filterless models, can efficiently remove difficult dry substances, such as
plaster
Plaster is a building material used for the protective or decorative coating of walls and ceilings and for Molding (decorative), moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of ...
dust, spilled
flour
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many culture ...
,
laser printer
Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively-charged cylinder called a "drum" to d ...
toner
Toner is a powder mixture used in laser printers and photocopiers to form the printed text and images on paper, in general through a toner cartridge. Mostly granulated plastic, early mixtures only added carbon powder and iron oxide, however, ...
, metal
knockout slugs, and wire clippings from electrical work, or even small pieces and slivers of broken glass. This ability may depend on the ability of the filter bag to resist clogging or breakage; filterless models are capable of removing the widest range of materials. "Wet vacuum interceptor" accessories are available for some systems; these operate by separating liquids from the dirty airstream prior to passage into the in-wall piping and central unit. These "wet vac" units are subject to the same limitations as "wet-or-dry
shop vacuums", and must be washed out and dried after use to prevent unpleasant odors and
mold
A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...
growth. However, toxic materials, such as
asbestos
Asbestos () is a naturally occurring fibrous silicate mineral. There are six types, all of which are composed of long and thin fibrous crystals, each fibre being composed of many microscopic "fibrils" that can be released into the atmosphere b ...
should never be cleaned up with anything but specialized equipment made expressly for the purpose.
* Complete removal of
allergen
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
In technical terms ...
s and noxious
odor
An odor (American English) or odour (English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is caused by one or more volatilized chemical compounds ...
s — Central vacuums generally do not recirculate exhaust air back into the space being cleaned.
This contrasts with the well-known acrid "vacuum smell" of
fine dust and hot air exhausted from a portable vacuum. Instead, central vacuums exhaust spent air into a utility space, or directly outdoors. An external exhaust outlet can be easily concealed under a porch or behind shrubbery, but in any case is less obtrusive than a standard
clothes dryer
A clothes dryer, also known as tumble dryer or simply dryer, is a powered household appliance that is used to remove moisture from a load of clothing, bedding and other textiles, usually shortly after they are washed in a washing machine.
Many dry ...
appliance vent.
* Low
acoustic noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arise ...
— Well-designed central vacuums are very quiet at the point of use, since the powerful motor is located remotely in a utility space. This is a benefit to the person vacuuming, as well as anybody else occupying the space being cleaned, who otherwise might be woken up or driven out by the loud whine of a portable machine.
* Convenient cleaning — Setup, use, and storage of a vacuum hose and cleaning tool can be quick and efficient. Cleaning stairways is much easier without having to balance a heavy, hot appliance on each step, and coping with both an electrical cord and a vacuum hose.
* Infrequent emptying — Central vacuums can usually accumulate up to 10 kg (22 pounds) or more of dirt and dust before requiring disposal. This is an unavoidable dirty process that must be performed for any vacuum cleaner, but can be done much less frequently, perhaps a few times per year. Disposable filter bag systems are easy to empty, though care must be taken to refit the replacement bag to allow maximum airflow without leaks. Emptying the dust canister of a cyclonic vacuum is best done outdoors on a breezy day because of the fine dust cloud that can be released.
* Low consumables cost — For filterless systems, there are no ongoing costs, other than occasionally replacing a worn-out motor brush or vacuum hose.
* Compatible with standard tools and accessories — Most central vacuum hoses are compatible with a wide range of industry standard brushes and tools used with ordinary portable vacuum cleaners. In the United States, the
de facto standard
A ''de facto'' standard is a custom or convention that has achieved a dominant position by public acceptance or market forces (for example, by early entrance to the market). is a Latin phrase (literally " in fact"), here meaning "in practice b ...
size is 1
1/
4 inch (3.175 cm) inside diameter for tools. For some accessories, it may actually be necessary to "bleed off" excessive suction, usually by partially opening a small bleed port on the side of the vacuum hose handle, provided for that purpose.
* Reduced damage and wear to furniture and walls — There is no heavy or awkward canister or other motorized unit to carry from room to room when vacuuming. Only a lightweight vacuum hose and the cleaning tool being used need to be carried.
To further reduce wear to furniture feet and projecting baseboard corners, a soft woven "hose sock" can be installed over the corrugated vacuum hose.
* Durable equipment — Good-quality central vacuum systems can last indefinitely, perhaps requiring replacement of the motor brushes once per decade of use.
Besides using heavy-duty components, central vacuums avoid the damage caused by accidental dropping or collisions of portable equipment with fixed objects. Many manufacturers give a "Lifetime Limited Warranty" on all permanently installed components of a central vacuum system.
Disadvantages
The chief disadvantage of central vacuums is higher initial cost. In the United States, the average central vacuum system has an installed cost of around $1,000.
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.
A central vacuum system is generally considered by building owners a permanent
fixture of the building where it is installed, similar to plumbing and electrical fixtures. A short-term renter would most likely lose any investment made in improving the property, unless a prior agreement were to be made with the property owner. Installation of a quality central vacuum increases the
property value
Real estate appraisal, property valuation or land valuation is the process of developing an opinion of value for real property (usually market value). Real estate transactions often require appraisals because they occur infrequently and every pr ...
of a residence or commercial property.
Maintenance
![ZentralStaubsaugAnlage](https://upload.wikimedia.org/wikipedia/commons/1/1e/ZentralStaubsaugAnlage.jpg)
Central vacuum systems require periodic emptying of the dirt canister or replacing the filter bag, typically 2–4 times per year.
In some models, it is also important that the filters be changed frequently, especially for designs where the just-filtered air passes through the motor for cooling. 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. Many cyclonic vacuum systems now feature
translucent
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions a ...
dirt collection canisters, allowing quick inspection without removing the canister.
Regardless of which dirt separation system is used, the electric motor may require lubrication of its
bearings, or replacement of
carbon brushes
A brush or carbon brush is an electrical contact which conducts current between stationary wires and moving parts, most commonly in a rotating shaft. Typical applications include electric motors, alternators and electric generators. The lifespan ...
on an infrequent basis, usually measured in years.
Rarely, a central vacuum system may become clogged, especially if the piping was improperly installed, or if the system is abused by vacuuming sticky substances (such as paint or glue or wet foodstuffs).
A homeowner can usually use simple tools and techniques to locate and remove the obstruction,
or can hire a professional vacuum installer to do repairs. The flexible hose is often the location of a blockage, which can usually be dislodged by using a
plumber's snake
A plumber's snake or drain snake is a slender, flexible auger used to dislodge clogs in plumbing. The plumber's snake is often reserved for difficult clogs that cannot be loosened with a plunger. It is also sometimes called a toilet jack. A plumb ...
.
Installation
![FEMA - 285 - Hazard Mitigation - raised water heater](https://upload.wikimedia.org/wikipedia/commons/4/46/FEMA_-_285_-_Hazard_Mitigation_-_raised_water_heater.jpg)
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. The most important safeguard is at the vacuum inlets, which are intentionally designed with a tighter
radius of curvature
In differential geometry, the radius of curvature, , is the reciprocal of the curvature. For a curve, it equals the radius of the circular arc which best approximates the curve at that point. For surfaces, the radius of curvature is the radius o ...
than any other bends in the system. This is done to ensure that if any vacuumed debris becomes stuck, it will jam right at the inlet, where it is easiest to discover and to remove. Well-designed central vacuum piping rarely or never clogs unless severely abused (e.g. vacuuming wet plaster, wet flour, or other sticky substances).
The wall inlets are connected to the power unit by piping which can be run inside walls, or through vertical pipe chases, closets, the attic, basement, or the cold air
return ducts (if permitted by
building code
A building code (also building control or building regulations) is a set of rules that specify the standards for constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permission ...
). 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
Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HV ...
, electrical, etc.), and just before
drywall
Drywall (also called plasterboard, dry lining, wallboard, sheet rock, gypsum board, buster board, custard board, and gypsum panel) is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thick ...
, paneling, or other surface finishes are installed. However, there are advantages to installing vacuum piping ''before'' cabling (for electric power, telephone, LAN, etc.), since routing of wiring is usually less constrained than piping. In a similar manner to plumbing and electrical fixtures, the vacuum inlet fittings and final connections are installed in a finish phase, after the wall finishing is complete.
Vacuum piping systems may be installed by
electrician
An electrician is a tradesperson specializing in electrical wiring of buildings, transmission lines, stationary machines, and related equipment. Electricians may be employed in the installation of new electrical components or the maintenance ...
s,
plumber
A plumber is a tradesperson who specializes in installing and maintaining systems used for potable (drinking) water, and for sewage and drainage in plumbing systems. s, specialized contractors, or even
do-it-yourself
"Do it yourself" ("DIY") is the method of building, modifying, or repairing things by oneself without the direct aid of professionals or certified experts. Academic research has described DIY as behaviors where "individuals use raw and semi ...
(DIY) homeowners.
Retrofitting of vacuum piping in existing structures can be surprisingly straight forward or more difficult, depending on the anatomy of the building. A home remodeling project can generate large amounts of irritating plaster dust and other demolition and construction dirt. 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.
![Central Vacuum Floor Inlet](https://upload.wikimedia.org/wikipedia/commons/c/c3/Central_Vacuum_Floor_Inlet.jpg)
A typical house requires 2–4 inlets per floor, although many users find the central vacuum so convenient that they later install additional inlets in the basement, attic, garage, and even on the back porch (for vacuuming car interiors, storage sheds, etc.). A rough rule of thumb is one inlet per of floor area.
Inlets should be placed in convenient locations unlikely to be blocked by open doors or furniture, such as in central hallways. A non-stretchable cord of appropriate length (or a thin wire on an
architectural scale drawing) can be used to check for adequate reach of a vacuum hose.
Routing and design of vacuum piping layout is very similar to
drain-waste-vent (DWV) plumbing, with the exception that pipe pitch or gradient for drainage is not required. Vacuum system designs share with DWV designs a concern about eliminating internal roughness, ridges, burrs, sharp turns, pockets, or other obstructions to smooth flow that might cause build-up of material into pipe blockages. Piping for central vacuums has a few peculiar constraints of its own, and a few unusual capabilities, such as the ability to run a pipe straight upwards after a sufficiently long horizontal "running start". In some jurisdictions,
fire code
Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent the ignition of an uncontrolled fire and those that are used to limit the development and eff ...
regulations require that an
intumescent firestop collar be installed around the pipe when it penetrates a
firewall
Firewall may refer to:
* Firewall (computing), a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts
* Firewall (construction), a barrier inside a building, designed to limit the spre ...
. If a pipe runs through an unheated space, it may require external
pipe insulation
Pipe Insulation is thermal or acoustic insulation used on pipework.
Applications
Condensation control
Where pipes operate at below-ambient temperatures, the potential exists for water vapour to condense on the pipe surface. Moisture is known to ...
to prevent water vapor from condensing inside. These and other installation details are described in installation manuals available from manufacturers.
Two different diameters of thinwall (typically 20 gauge or "
Schedule 20") plastic piping have traditionally been used in the US.
For years, HP Vacuflo advocated the slightly smaller piping size (outside diameter), claiming that their studies showed that it was less likely to clog. However, that manufacturer has also switched to the
de facto industry standard size of outside diameter piping and corresponding fittings. In most cases, the end user need not be aware of the piping size in a central vacuum system, but the piping size must be considered when extending, modifying, or repairing a system. Size adapters have been made to allow interconnection of the two sizes when necessary.
Another piping option, which is becoming popular in commercial applications and with DIYer's, is "
Schedule 40
Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures. "Nominal" refers to pipe in non-specific terms and identifies the diameter of the hole with a non-dimensional number (for ...
" standard 2-inch plumbing pipe. The main advantage of plumbing pipe is widespread availability, slightly larger diameter, and thicker walls. The thicker material increases durability and ruggedness in installations where pipe runs are exposed to mechanical damage or abuse (although this has rarely been reported as a problem with thinwall piping). The primary disadvantage is that the thicker material makes pipe less flexible, heavier, and somewhat more difficult to work with. The thicker pipe walls increase the outside diameter of the pipe to , requiring fittings designed for this. To use plumbing pipe for central vacuum installations, special adapters (available from many central vacuum retailers) are required to connect the plumbing pipe to the central vacuum inlets and power unit.
Occasionally, the owner of a new house under construction may choose to preinstall vacuum piping and control wiring in the walls, but to defer purchase of the central unit, hose, and tools to reduce cash flow requirements. Installing piping and wiring for a central vacuum in new construction is definitely much easier if done before the drywall and other wall finishes. The short-term cost savings of deferring full system completion should be weighed against the great convenience of having a functional vacuum system, especially during the commissioning and move-in period, which generate more than the usual amount of debris to be cleaned up.
See also
*
List of vacuum cleaners
This is a list of vacuum cleaners and vacuum cleaner manufacturers. A vacuum cleaner is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from floors, and optionally from other surfaces as well. The dirt ...
*
Pneumatic refuse conveying system — larger central vacuum systems used to dispose of industrial or municipal rubbish
References
{{DEFAULTSORT:Central Vacuum Cleaner
Vacuum cleaners
Home appliances