Brushless dc blowers from Rotron feature electronically commutated motor technology without brushes that extends service life up to 60,000 h on heavy-duty transit buses, construction vehicles, and off-highway equipment. The blowers operate maintenance-free and decrease the motor failures associated with brush wear over time. Suitable applications include A/C evaporators, underseat heaters, defrosters, and driver boosters. The blowers can accept voltage inputs of 12 or 24 V dc and offer flows up to 6523 gal/min (24,692 L/min) and output pressures up to 0.117 psi (0.008 bar). Lightweight molded plastic construction resists harsh environmental conditions including hot-water spray, salt, fog, shock, and vibration. Blowers can be engineered to deliver multiple or variable speeds without the use of dropping resistors.