Sunday, December 22, 2013

Filtex Central Vacuum Systems


The Filtex Corporation began in the 1930s in Los Angeles, making a tank-type vacuum cleaner similar to Electrolux.  Their first models looked like this:


Most every portable vacuum manufacturer made a unique set of attachments to go with their vacuums.  Filtex was no different, and their attachment set (including patented “Rollex” carpet tool) was one of the finest:


During the 1950s, as lightweight PVC tubing, modern low-voltage controls, and small but powerful universal-type vacuum motors combined to make residential central vacuums a much more affordable concept, Filtex became one of the pioneers in this field.  The power unit they manufactured was called the “Perma-Vac”:


A distinguishing mark of all Filtex machines is the casting on the lid, which is actually an airflow duct which directs debris into the bag.  It also incorporates a utility inlet valve for cleaning near the machine.  This lid casting allows the bag’s cardboard rim to rest at the top of the canister, instead of on a rim several inches down as with competing designs (Modern Day and Central Vac International).  While this makes emptying easier, the tight bends can clog easily, and reduce airflow at a rate equivalent to 40+ feet of straight pipe:


Initially the Perma-Vac unit was made concurrently with Filtex tank vacuums.  However, soon thereafter, Filtex stopped production of portable cleaners, and focused their entire business on built-in vacuum systems.  The Perma-Vac, with its single small motor, only worked well in small homes with two or three inlet valves.  The machine could be ordered with or without a low-voltage control, which used a doorbell button at each inlet to start and stop the machine, and a light to indicate when it was running:


By the late 1960s, Filtex had several machines available to handle larger installations:



The “NMC” logo on the nameplate above stands for Natter Manufacturing Corporation, which had purchased Filtex years earlier.  The company was now based in Temple City, California, where it remained for nearly twenty years.  In the early 1970s, “VSI” started appearing on the nameplate – this was now the parent company of Natter Manufacturing.  Units also changed to a lighter blue color, and more models were introduced:



Those who purchased Filtex systems now also had a choice of “Pushbutton and Light” inlets (which used a latching relay) or “Automatic” inlets, which turned on when opened and used a more standard relay.  Automatic inlets soon became standard and it wasn’t long before the pushbutton-and-light inlets were discontinued.



Filtex whole-house vacuum units looked largely the same throughout the 1970s, with the exception of two changes made in the mid- to late-seventies: the heavy aluminum airflow duct casting on the lid was changed to plastic, and the large chrome lid latches (which were hold-overs from the Filtex tank cleaners of the 1950s) were replaced with small, off-the-shelf toggle latches.

In 1980, the company was sold to Fairchild Industries, which moved production to La Verne, CA.  Machines made in the early 1980s show this address on their nameplates.

Several years later, Fairchild sold Filtex to Music & Sound, a Dallas-based manufacturer of home radio intercom systems.  Mid-eighties units will say “M & S Filtex” in script on the logo.  Several new models were introduced at this point, including their first enclosed dual-motor units (TSP700L) and their first triple-motor units (TM285L) which were inspired by MD Manufacturing’s triple motor units which had been successfully used in larger installations for several years already.


The late 1980s saw several significant design changes, and the new models had an “N” at the start of their model number: NTM285, NTC600, NTSP700, and so on.  The large machines that used to require a 120-volt, 30-amp circuit were now configured to run on a 240-volt, 15-amp circuit.  Parts like the bottom motor cover were now molded plastic instead of sheet metal, and the lid/bag gasket design was improved for a more positive seal. 


Around this time, a cost-saving decision was made to discontinue the metal Automatic inlet valves, and the metal Filtex attachments.  This shift toward off-the-shelf inlet valves and attachments took away a big part of the uniqueness that distinguished Filtex from competitive systems.  The units, which had been light blue since the early 1970s, were painted very dark blue starting in the early 1990s:


You can tell a mid-1990s machine by its “FX” model number (FX500, FX775, FX900) and the new Filtex logo:


Another color change came in the late ‘90s, to a very light gray.  This coincided with the purchase of M & S by Chamberlain, manufacturer of garage door openers and other products.  Also at this time, nearly all dual motor designs were replaced with single motor units (FX2000, FX3000, FX800), the only dual-motor machine being the 240-volt FX900.  This was done as new motor technology allowed a single high-efficiency motor to produce cleaning power that previously was available only in a dual-motor design.  At the same time, the large flocked secondary filter was replaced by a very small (2 1/2” square) hidden filter that would plug with fine dust, greatly restricting airflow. 


The early 2000s saw the Filtex name completely eliminated.  Machines remained unchanged, but now bore the label “AirVac”.  This brand had been manufactured by M & S since the mid-1980s, and up until this point was a line of bagless units with either one or two motors, and foam (later cloth) filters.  After the brand consolidation, rather than “Filtex” being a bagged machine and “Airvac” a bagless as before, the Airvac “Blue” name now indicated a disposable bag unit, and “Red” were the bagless models.  A new “Gold” series offered extra-quiet operation, and system monitoring technology that would flash an LED on the machine and at the inlet valves when service was required. 


Around 2006, production in Dallas, Texas ceased, and the entire model range was discontinued.  The new AirVac Red (bagless) and Platinum (disposable bag) machines are no longer made in the United States.  Though several models are offered for different home sizes, the suction performance is very similar, and all models (even the 240 volt machine rated for 12,000 square feet) have only a single two-stage, 5.7” non-serviceable motor.  While good performers, the quality of these machines makes it apparent that their lifespan will be measured in years, not in decades.


Today, very little remains of the Filtex Corporation.  The units produced by its descendants bear no resemblance to those on which the company’s reputation was built.  Fortunately, Just Central Vacuums has a full stock of parts and supplies to keep old Filtex central vacuums working for decades to come.  Visit or call (630) 608-0175 for help with your vacuum system.

Monday, June 24, 2013

Attic Piping


Recently, I was called out to evaluate a Eureka central vacuum system in Naperville, IL.  The owner indicated that the system “just didn’t work right” and she wanted me to check it out and see what was wrong.  Inspection of the piping system revealed a very poor installation.  Look at the way the piping for the second floor inlets was routed through the attic:


Where to start…first, the fact that the pipe is running about a foot off the surface of the joists makes it difficult to maneuver around, difficult to insulate, and prone to sagging (as evident in the gray piece).  The tee connection to the right of the photo is a “drop-out” (we can assume the installer was also) – it allows debris traveling to the power unit to collect in the branch line below the inlet.  Fortunately, since many of the connections in this system had never been glued, this was easy to correct:


Fixing this involved cutting the risers to slightly below the surface of the joists, then gluing 90 degree elbows in place.  Note the horizontal 90 elbow leading into a 45 degree wye: This arrangement ensures no debris remains in the tubing system, reducing the potential for clogs.

Not shown is the final step of adding loose fill insulation to cover the pipe, which prevents condensation buildup in the wintertime.  Much easier now that the pipe lays flat on the attic floor. 

Here’s a shot of one of the basement lines from the same system:


Not one, but TWO drop-out points for debris to collect.  Dirt would pour out of the inlet on the left whenever it was opened.  I didn’t take an “after” shot once the tubing was re-done properly (nor did I document the many tight 90-degree turns that were taken out and replaced by the proper sweep 90s), but needless to say, this system is working much better now.

Wednesday, May 8, 2013

Inlet Valves, Pt. 2: Non-Standard Inlets

In the past and even today, some inlets are used that do not fit the industry standard form factor of the inlet valves in Part 1.  Here I will cover some of those inlets, their features as well as how to update them to modern, standard inlets.

The very earliest central vacuum inlets were just terminations for the piping, without any electrical contacts to activate the system.  Up until the 1950s, systems were installed with threaded iron piping, and inlets were similarly threaded into the piping.  Here are two examples from early 1900s systems:

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It would be theoretically possible (though not often attempted) to adapt modern inlets to the threaded pipe size and run low voltage wire for activation of a modern system.  These older systems were turned on from a central point and designed to run continuously until cleaning was completed, similar to the way large commercial systems of today are operated.  A modern residential system should make use of low-voltage wiring or a wireless remote control.

Starting in the 1950s, small but powerful universal motors and lightweight, low-cost PVC tubing combined to make central vacuum systems a much more affordable option that began to be included in homes of all sizes.  One early pioneer, Filtex, made a very popular, high-quality system and manufactured their own inlets and attachments.  The original inlets used in the 1960s and occasionally seen into the late 1970s had a round door, with a momentary pushbutton to start or stop the power unit, and a light to indicate when it was running:


A nearly identical inlet was used by Central Vac International during the same time period, though there were slight cosmetic differences.  Many times when putting a system into a house that was already built, installers would put these in the floor, as shown here.  If the family pet walked over the button, the system could run for hours before it was discovered, causing the motors to overheat.  This concern, plus cost and aesthetic considerations, caused Filtex to develop the simpler Automatic-type inlet:


This inlet was usually supplied in painted ivory, though stainless steel, polished brass, and antique bronze were available too.  It had a plunger switch inside that turned the system on when the door was opened:


Many, many systems in the Chicago area use this type of inlet.  Most modern central vacuum hoses fit loosely and can pull out, but we stock a hose that fits perfectly and is much lighter weight than older hoses.  Just make sure when calling to mention that you have a Filtex or Air-Flo central vacuum system to get the proper hose. 

Both styles of Filtex inlets can also be easily replaced with industry standard covers, which turn on when the hose is inserted, and allow the use of convenient low voltage hoses having a switch right at the handle. 

Another pioneering central vacuum manufacturer starting in the 1960’s was NuTone, famous maker of door chimes, bath fans, intercom systems, and other built-in home conveniences.  From the beginning, NuTone manufactured their own distinctive inlets:


These inlets, still used today, are notable because of their nearly square shape, screws on either side of the neck, and an inside diameter just slightly smaller than the industry standard 1 1/2” – enough of a size difference to cause standard hoses to fit too tightly, and not bridge the contacts to activate the system.  It is relatively easy to change these inlets to standard Hayden or Canplas inlets, but CycloVac Deco inlets are especially easy to retrofit.  As an alternative, you can request any type of hose to be modified so that it fits NuTone inlets easily. 

Vacuflo inlet doors have always been unique and easy to distinguish from standard inlets.  In the 1950s and 1960s, Vacuflo systems were installed with thinwall metal tubing.  The system turned on when an inlet was opened, thanks to a pair of contacts in the inlet door hinge.  Inlets looked similar to standard “Round Door” inlets, but with a wider “pull tab” at the top:


The 1960s brought several important innovations to Vacuflo systems, including built-in low voltage control relays, lightweight PVC tubing for easier installation, and patented Lexan “Magic Valves”:


These turned the system on when opened, and included a provision for a low-voltage hose to be used (far in advance of the technology in use by competitors at the time).  Exact replacements are still available today, as are the special low-voltage hoses with two pins which make contact with the two holes above the inlet opening.  Alternatively, it is possible to update to standard inlet valves using an adapter plate between the original rough-in frame and the new inlet cover.

One widespread proprietary inlet valve design was used by Sears Kenmore central vacuum systems in the 1960’s and 1970’s, before the company switched to standard tubing, fittings and inlet valves sometime in the ‘80’s.  The first incarnation required the user to press a brass contact strip once to start the system, and again to stop:


Like the original Filtex inlet valves, these required the user to manually start and stop the system, and could allow the motor to run with all the inlets closed.  Once these problems became apparent, Kenmore systems by the mid-1970’s had inlets that turned on when opened, and off when closed:


These simple, reliable inlets remained current until Kenmore transitioned to industry standard 2” OD vacuum tubing and 1.5” ID inlet valves sometime in the 1980’s.

Black & Decker was another innovator in the central vacuum industry, developing their own power units, tubing, fittings and inlet valves starting in the 1960’s.  These systems were marketed by WalVac, Inc.  Inlets were unique in several ways: First, they were installed without a mounting plate, simply friction fitted into the 90 degree elbow, and fastened to the wall with three toggle bolts.  Second, they activated the system with a push button under the inlet hole, which was contacted by a flange on the hose end.  These provided the same effect as modern inlets (turning on upon hose insertion and turning off upon removal), and allowed the use of a non-latching relay.  Original versions were brushed aluminum, and had a unique oblong shape:


Sometime in the 1970’s, Black & Decker began to make the inlets out of plastic, with contact points in the inlet neck like industry standard inlets.  However, these were dimensionally the same as the original style, and thus required a hose just slightly smaller than the industry standard 1.5” in order to fit properly.

For lack of pictures, I have left out at least one rarely-seen style from the 1960’s; that which looked like the early Filtex/CVI push-button inlets, but had a second push button in place of the red light – one to start, one to stop.  I ran across this type of system once, on a “Turbo Vac” installed in Lisle, IL.  While I didn’t think to get a picture of the inlets, I did snap one of the unit:


It’s my hope that this information has been informative and interesting.  I would love to hear from owners of any of the above systems, whether you have a need for service or just would like more info about your system.  Also, if you have a system so unusual you don’t even see it here, it would be especially helpful to me for you to send photos of your system to:

My plans for world domination will not be complete until I have cataloged every known variation of central vacuum inlets known to man!  Buwahahahaha!