Direct-drive blower HVAC AC engines turn the blower wheels and fan blades mounted on the actual engine shaft. These motors provide a smooth operation, with reduced noise and less vibration than belt-drive models. A key advantage of this is that direct-drive blower engines don’t possess belts that get worn out and need replacement. These engines are generally utilized in HVAC maintenance and repair procedures where HVAC engines with the same specs are replaced. This process is conducted on the premise that the hardware then circulates the air freely, without compromising performance.