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?”

This entry was posted on Thursday, August 17th, 2006 at 3:35 pm and is filed under MD Products, CV Facts, Competitor Products. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.