by Bob and Ron Boffoli
We started our business, Cape Cod Vacuum Mart, back in the
1980s, selling portable vacuums and only the occasional central
vacuum system. As convenient as they are, it has taken up until
the last several years for central vacuums (CVs) to begin to
catch on in this country. Currently, only about 200,000 CV
units are installed annually in the United States (according to
an industry spokesman, this represents a 2% to 3% market
penetration). Meanwhile, north of the border, Canadian builders
and homeowners made central vacuums a standard item back in the
1960s — according to Mark Bruneau of Industries Trovac,
CV systems in Canada "are as common as toilets." In fact, in
the mid-80s, we'd set up a booth at a home show and the most
common reaction to our CV display was, "What's that?" Today, we
have three trucks on the road installing nothing but central
vacuums, which represents a full 50% of our current business.
In spite of this brisk trade, the popularity of CVs remains
regional, with installations mostly concentrated in the
Northeast, the Northwest, California, the Southwest, and
Why Install a Central
An important reason is health. One in three people in the U.S.
has dust-related allergies. Even though portable vacuum makers
may call attention to their HEPA (high-efficiency particle
arrestor) filtration, the seal around the filter is often
ineffective, allowing microscopic dust to bypass the filter and
recirculate in the room. Ordinary dust bags offer no resistance
to these tiny particles; microbe-laden dust passes through a
standard bag like a fly through a chainlink fence. By contrast,
CVs have standardized superior built-in filtration, and many
models can be exhausted directly to the outdoors. Even when
vented to the outside, high-grade filtration ensures that
exhausted dust won't collect on shrubbery or walkways.
The second reason is power: While the average portable
vacuum has an airflow of 60 to 90 cubic feet per minute (cfm),
one of our dual-motor CV units responds with 185 cfm. Because
of the remote location of the power unit, the sound produced by
a running CV (without a power head) is not much louder than a
person forcefully exhaling. It's easy to talk over the sound of
an operating central vac, and TV, music, and telephones remain
clearly audible. Where remote installation isn't practical,
many manufacturers offer super-quiet power units for
installation within the living space.
Finally, a CV system eliminates the need to drag a clumsy
machine around the house, banging up walls and furniture in the
process. Portable vacs have to be lugged up and down stairs,
sometimes descending on their own when tugged while cleaning.
CV container capacity is generous, too; it usually requires
emptying only once per year. As a final enticement to the
homeowner, built-in systems typically retain their full value
when a home sells — something that can't be said for a
Yesterday and Today
The typical system of the 1960s included PVC plastic tubing
and a separate run of low-voltage wiring. To activate the
motor, you inserted the metal-tipped vacuum hose into the wall
valve, which closed the circuit between two contact points in
the valve. The system shut off only after you removed the hose
from the inlet. Although this was still more convenient than
hauling a portable machine around, under-powered units, poor
system configuration, and amateur installations all served to
dampen the popular interest in central vacuums.
Today's equipment is vastly improved. In-wall tubing is
dedicated 2-inch-diameter, vacuum-rated PVC, similar in
appearance to schedule-20 pipe. The best tubing is made of
virgin PVC; regrind content in lower grade PVC can have a rough
interior finish that creates airflow friction. The standard
wall valve is equipped with 20-gauge, low-voltage wiring to
control the main power unit (Figure 1). However, rather than
being activated by hose-insertion at the inlet, the low-volt
wire continues inside the hose coils to a rocker-switch at the
nozzle. This makes it more convenient to pause during
vacuuming, to answer the phone for example. In carpeted rooms,
the inlet will typically include a line-voltage circuit to
operate a power nozzle attachment.
1. Low-volt, 20-gauge wire makes a home run from
each inlet valve to the power unit. Contact points in
the hose base connect the circuit to an on-off switch
in the wand.
Even if the homeowner doesn't want to spring for the full
system initially, it's still a good idea to install the tubing.
It's an easy and inexpensive job, especially in new
construction. The average cost of a rough-in — wall
valves mounted, tubing stubbed to basement, garage, or utility
room — is $80 to $120 per valve by region. A
2,000-sq.-ft. home usually requires a minimum of three
use a 2 1/4-inch-diameter spur bit to bore the necessary holes
through the framing, walls, and floors. Tubing comes in 8-foot
and 10-foot lengths but, unless the ceiling height is over 8
feet, we stick with the 8-foot tubing to reduce cut-off waste.
We cut the tubing with a special thin-wall tubing cutter
(Figure 2) to avoid leaving rough, burred ends that can snag
vacuumed dust and hair. The tubing sections are joined with
solvent-weld adhesive, just like plumbing lines.
2. A thin-wall tubing cutter ensures clean,
burr-free cuts for unimpeded airflow within the
Short 90-degree elbows are best reserved for use at the
inlet connection, where there’s usually not enough room
for a sweep. All other offset jogs should be configured with a
full-sweep 90 or two 45-degree ells to ease the radius and
reduce airflow resistance (Figure 3).
3. Short 90-degree ells are used at the inlet
valve only. Full-sweep 90s elsewhere ensure
unrestricted airflow in the system tubing.
For best results, wait to install the tubing until the
electrician and plumber have completed their rough-ins. That
allows you to match the height of the inlet valve to the outlet
boxes in the room and avoid conflicts with plumbing and wiring
runs (Figure 4).
4. To avoid conflicts, central vac tubing is
best installed after the electrician and the plumber
have completed their rough-ins. Inlet valves can also
then be mounted to match electrical box