Under normal operating conditions, a typical central vacuum will move about 40-100 CFM (airflow) if used with a power brush on carpet. An avg. 2,500 sq. ft. home contains appx. 20,000 cubic ft. That would equate to replacing the entire amount of air in the house in about 3 to 8 hrs. Vacuuming for 30 min. would suck up 6 to 6.25% of the air in the home. But where does that air come from? It comes from the outside. But how does it get in? Our homes are not so tight that the windows implode when we run the vacuum too long! Air must come through microscopic holes and pores in every surface. It comes through the drywall, flooring, windows, and doors. One open door for 10 seconds could bring in 1,400 cubic ft. of air (or 7%)—this is estimated from a person walking in at 4 mph and the airflow associated at a 7′ x 3.6″ opening. If we were really concerned about this we would air-lock the doors to our homes!

It is true that outdoor air has less particles per million. But they often contain pollens and other irritants. For the most part, these agents are filtered out as the air enters the home. This is because airflow from the vacuum into the home through the microscopic permeations is of such a small total volume that these bothersome particles cannot come in. Indeed, they can hardly move. When a vacuum nozzle is set two ft. from a dust column, the dust will barely move!

All this to say that homes really can be cleaned extremely well. And by far, a central vacuum is the best appliance for maintaining the cleanest home possible, since it removes much more dirt than conventional vacuums. For more information, visit MD’s health facts page.

MD is the only central vacuum manufacturer who offers the most-admired power brush in the industry. In fact, we are the only company who sells and distributes the highly-acclaimed Stealth power brush. We have trademarks on the Stealth name and have created a vast cornucopia of information about it on our website.

The Stealth brush comes in 12″ or 14″ and we carry the kits with 25′, 30′, or 35′ Plastiflex’ hoses. The rest of the kit includes top of the line equipment comprising a 14″ wide horse-hair floor tool, and other notable items.

Within a couple months we will be introducing the “Stealth II,” which has a quick-disconnect pedal, a telescopic stainless-steel wand that hides the cord, and an extremely user-friendly release system at the handle.

Take a look at all the features offered on the Stealth @ the Stealth page of our website.

MD Manufacturing, Inc. has the best warranty program around! Our SilentMaster, ModernDay and AirForce power units are warranted against electrical component failure for up to 6 years. Any parts (excluding filters) required within the first 6 years will be supplied free of charge to our customers by the Authorized Dealer who originally sold the power unit to the customer.

Each SilentMaster unit is also guaranteed for life against defects in materials and workmanship. In the event an Authorized Dealer is not nearby, SilentMaster will honor and perform warranty services provided the power unit is returned to the factory, freight pre-paid. This warranty does not apply to commercial applications, misuse, abuse, acts of God, or if the unit has been worked on by an unauthorized person.

See also MD’s “Write Your Own Warranty” policy for more details on our commitment to having the most outstanding warranty in the industry.

In addition to warranties on our central vacuum units, MD also offers a Lifetime Warranty on our Stealth Belt, a 5 yr warranty on the motor, and 3 years on everything else.

Check out our competitors’ warranties. You’ll find that their warranties consistently last for shorter time periods, they often include “wear and tear” qualifiers, and they cannot be transferred to the new owners of your home.

Thru-flow motors (which depend on air traveling through them for cooling) are generally not used on central vacuums. This is because when they are sealed for any length of time, the motor does not get adequate airflow and it will often overheat. Since the power unit is in a remote location, the user has no idea that the motor is revving up while not receiving the necessary airflow—they cannot hear it.

Sadly, many central vacuum manufacturers are stooping to thru-flow motors to reduce their costs and boost their performance stats. I have seen them on Beam, VacuMaid, Nutone, and Air Vac units.

Thru-flow motors typically cannot be used on cyclonic units because the fine dust not caught by the filter is easily blown into the armature and windings, which causes premature failure. Ametek is one motor company that does not cover this issue in their warranty.

For more information about central vacuum motors, visit MD’s definition of thru-flow motors or our FAQ section where we answer the question, “Do all central vacuums use the same motors?”