How to Select a Central Vacuum Cleaning System or, Where Does that Dirt really Go? - March 2001

-- WESTFIELD: The History of Central Vacuums:  There are, today, a considerable variety of Central Vacuums available for home and office use. The Central Vacuum System (CVS) industry in the United States has, essentially, come from Canada where almost 85% of homes have CVS - in the USA the amount of CVS installed in homes is still relatively small.  In the 1980s a variety of existing American vacuum manufacturers decided to infiltrate the growing CVS market and, with the inclusion of their products and additional advertising, the public awareness of CVS increased.  In addition to these new CVS manufacturers swelling the ranks, additional Canadian CVS manufacturers occasionally choose to enter the United States market; and, thus, the choice of CVS for the consumer is steadily growing.

The Nature of a CVS:  A Central Vacuum System in its inherent design performs like a traditional canister vacuum.  This is to say that a CVS provides cleaning power (suction & airflow) by means of a motor - or, in some systems, two motors - located in the main canister. This cleaning power is made available throughout a house (or office, etc.) by means of plastic (PVC) tubing (usually PVC - sometimes metal is used and sometimes - horrors! - flexible hosing is used) located inside the existing walls, ceilings & floors of the house which is ducted to various CVS outlets into which a vacuum hose can be inserted.  Thus, in normal usage, the user inserts one end of the hose - usually 30 feet to 35 feet long - into the CVS wall outlet and the CVS obediently turns on.  Some hoses incorporate switches on the accessory end of the hose that enable the CVS to be turned on or off from the hose; rather than plugging or unplugging the hose from the wall outlet.  On the other end of the hose can be mounted various, traditional cleaning accessories such as dust brush, crevice tool, upholstery tool, wands & rug nozzle, etc.  As well, revolving brush accessories can be used for cleaning carpeted surfaces.

Locations of CVS Outlets:  The CVS outlets are normally located by the installer - usually after consultation with either the homeowner or the builder (or architect) - in judicious locations in particular areas of the house to maximize the use of the CVS hose in that area to clean as much as possible before relocating to another CVS outlet.  Thus, in a wing of the house with three bedroom there might possibly be only one or two CVS outlets in a common hallway - not one in each bedroom, etc.  It is common in the average-size house (2,000 to 5,000 square feet) to have 3 to 6 CVS outlets.

Types of CVS Outlets:  CVS outlets come in various types and colors.  Most common today are plastic CVS outlets although metal is still used.  Usual colors are the traditional white or ivory. Most CVS outlets are wired with low-voltage relay wiring which carries 24 volts to the outlet from the main CVS canister's relay.  Then, either when the CVS outlet door is opened or when the hose end is inserted into the CVS outlet the relay on the main canister switches the vacuum on.  Sometimes CVS use wireless methods to activate the main vacuum unit; however, this is usually the exception rather than the rule. Some CVS outlets are also wired with 110 volts.  In this instance, a small 110V receptacle is included in the CVS outlet immediately adjacent to the round opening on the CVS outlet into which the hose is inserted.  The end of the hose, then, is designed with a small set of 110V prongs which plug into the corresponding 110V receptacle on the outlet.  This provides 110V through the current-carrying CVS hose so that a motorized nozzle head can be used to clean carpeted surfaces.  This design eliminates either separate extension cords or pigtail extensions off the end of the hose which would then be necessary to power the nozzle head.

Types of Central Vacuum Systems:  

Cyclonic

Cyclonic systems use a cyclonic design to spin the air inside the dirt chamber.  This creates centrifugal force and is an effective way to maintain the airflow of the CVS which is critical to maintaining the cleaning efficiency. The dirt is thrown to the outside of the dirt chamber and then slides down into the bottom of the container. The downside to a standard cyclonic design is that the smaller dirt particles are not effectively thrown to the outside of the dirt chamber through centrifugal force simply because they weigh less than the larger particles.  These fine dirt particles exit up through the motor and back out into the atmosphere. Many CVS are vented outdoors for this reason of dirt leakage.  Since the motor(s) is getting dirty, it does not last as long.

(Paper) Bag

The advantage to a (paper) bag system is that the bag acts as a filter, and the air exhausting through the bag is being cleansed of dirt particles. The disadvantage of a (paper) bag system is that as the bag fills with dirt the airflow of the CVS reduces, thus impeding efficiency.

Cyclonic w/filtration

A cyclonic design with proper filtration offers the best of both worlds: The cyclonic design maintains cleaning power extremely well. The filtration ensures that the air is being cleaned before entering the motor(s) & before being exhausted back into the environment. The better units of this design will filter to as small as .1 micron.

Size & Power of CVS:  CVS come in different dimensions and power ratings to provide proper cleaning efficiency in various sizes of environments.  In most standard, in-home installations the need is to have a reasonably large dirt chamber.  Some CVS have quite small dirt containers and thus the cleaning power can be quickly reduced as the dirt chamber begins to fill. A proper dirt chamber size for normal home use is 6 - 8 US gallons. This is large enough to help maintain the cleaning power without premature emptying. The power/efficiency of a CVS is directly connected to the size & type of motor - or, motors - that is/are used: many CVS motors are 5.7 inches in diameter & have two fans. Some motors are 5.7 inches in diameter & have three fans. In given size motors with the same amperage rating & design each additional fan increases the cleaning power.

Some motors are 7.2 inches with two fans and some motors are 7.2 inches with three fans.

Larger (7.2 inch) motors generally provide more airflow than their 5.2 inch counterparts, and (7.2) motors also turn more slowly than their 5.2 inch counterparts and thus last considerably longer. The best motors are always 7.2 inch in diameter.

Some of the more powerful CVS sometimes use two motors rather than one motor. A twin motor CVS usually has two motors in series with the second motor intaking the air exhausting from the first motor - i.e., one motor is directly after the other motor. Such a design doubles the suction power (waterlift in inches) while the airflow remains the same. Some twin motor CVS use two motors in parallel in which case the two motors each pull air through a common intake.

Such a design doubles the airflow (cfm) while the suction remains the same.

Types of Cleaning Accessories:  The same types of accessories used on portable (canister) vacuums are available for CVS use: (1) Hose: (a) non-electrified for traditional accessory use. An electric power nozzle can be used via a special extension cord with a non-electrified hose (b)

Electrified for power nozzle use - one of two usages - either totally self-contained wiring using a "direct-connect" design; or, exterior electric "pigtails" for connecting either to a traditional 110V wall outlet at the "vacuum end" or the power nozzle at the "tool end" (c) 1 1/4 inch diameter hose in electrified or non-electrified (d) 1 3/8 inch diameter hose in electrified or non-electrified - 1 3/8 inch hose carries air better as it is slightly larger (e) New, stretch hoses non-electrified -a 6-foot hose stretches to 20+ feet for quick cleaning jobs.

(2) Accessories (a) Dust brush - the best ones usually have horsehair bristles as horsehair won't scratch like nylon bristles (b) crevice tool (c) Upholstery tool (d) Bare floor brush - the best ones usually use horsehair bristles so as not to scratch (e) Rug tool - combination rug/floor tools are well-designed and handy since it is convenient to quickly go from rugs to bare floors (f) Air-driven "turbo" upholstery or rug tools - utilize the airflow from the CVS to spin a revolving brush via a turbine in the tool. This design is considerably inefficient as the tool "steals" the airflow - and thus considerably lowers the overall cleaning efficiency - of the CVS. The attraction of this design is that it eliminates cords & electrical connections; however, the "trade-off" in loss of efficiency is too great to make it a feasible solution (g) Electric rug (or upholstery) nozzles (power heads) which necessitate electrical connections. This is convenient with the use of electrified hoses; much less so without such hoses. Such a design, however, maintains the all-important CVS airflow - and thus the cleaning efficiency - because the cleaning apertures remain fully open (unlike turbo nozzles which all use restricted apertures in an attempt to make the fan and brush spin fairly fast).

A good CVS is a solid investment for a clean and healthy home or office. It provides increased ease of use in cleaning, better cleaning power than any portable vacuum, and totally removes all the vacuumed pollutants out from the living space. It also contributes to the overall value of a residence or office if/when the time comes to sell the property.

For questions on Central Vacuum Systems - or, for any questions pertaining to proper cleaning of home or office, please visit The Eardly T. Petersen Company at 224 Elmer St., Westfield; or, contact them at 908-232-5723, e-mail them at sales@etpetersen.com or visit them on the web at www.etpetersen.com.