What a Way to Blow up a Blower!

Most residential and commercial HVAC equipment use centrifugal blowers to move air through duct systems.  The rate at which blower wheels turn is usually between 1000 and 1500 rev/min, depending on the application.  The point to be made is that blower wheels turn at a fairly slow speed.  Blower wheels that are attached directly to the motors that drive them turn at the rotational speed of the motor.  But, when the blower wheel is belt driven, the speed of the blower can vary depending on the size of the pulley attached to the shaft that drives the blower wheel.  If the size of the pulley attached to the blower shaft is twice as large as the pulley attached to the motor, the speed of the blower will be half of the speed of the motor.  If however, the blower pulley is the same size as the motor pulley, the blower will turn at approximately the same speed as the motor.  If the blower wheel is not designed for such speed, the centrifugal forces created by the rotational motion will cause the blower wheel to fail in a spectacular way.  The photos attached below illustrate the results.   

Blower louvers peeled away from blower ring

View of damage to blower louvers

Jeep Wrangler and Gladiator Vehicles Recalled

Fiat Chrysler Automobiles has announced that it has recalled 2018 – 2020 Jeep Wrangler and 2020 Jeep Gladiator vehicles equipped with manual transmissions.  These vehicles contain a clutch plate within the transmission that can overheat and fracture, posing a fire hazard.  If the fractured pieces crack the transmission casing and come in contact with combustible material, a fire can result.  Approximately 33,237 vehicles are involved in this recall.  Owners should be aware of signs indicating a problem: the sudden loss of power, burned clutch smell, and extra pedal travel when shifting gears.  At present, Fiat Chrysler is working on a repair but expects to begin recalling vehicles on April 22^nd of this year.  Owners of affected vehicles will receive notices of the recall by mail.  For additional information, owners can contact Chrysler customer service by calling 1-800-853-1403 and referencing Chrysler recall # W12.