One of the least expensive components of your HVAC system, fan-motor belts, regularly cause significant, added operating expense to your
Belts that are not properly or routinely maintained are a direct cause of HVAC-system inefficiency and down time.
Belt driven electric motors are in common use today. It is estimated that approximately one-third of the electric motors in commercial and industrial buildings use belt drives, including the motors in common HVAC equipment, primarily fans.
Belts, along with sheaves, allow for flexibility in adjusting the positioning of the motor relative to the load, so that fan speeds can be adjusted relative to the motor speed and provide greater operating efficiency.
Most belt-powered systems are relatively quiet, and operate at relatively high degrees of energy efficiency. In fact, V-belt drives can operate at peak efficiency of 95%. Operating efficiency, however, can deteriorate due to improper tension, belt wear, or misalignment. That’s why proper, routine maintenance is so critical to maximizing your building’s HVAC efficiency.
Checking belt tension as part of a systematic preventive maintenance plan is important because:
Performing regular checks, properly installing and maintaining belts can help prevent belt wear and failures. Here are some helpful hints to keep in mind.
Regular belt inspection may also help diagnose other problems, which when addressed promptly, can reduce the possibility of expensive repairs and/or avoidable down time.
Belts that were either misaligned or did not have the proper belt tension can cause the sheaves to wear prematurely.
Always inspect the sheaves for premature wear before replacing the belts. Eroded sheaves can reduce V-belt drive efficiency by up to 12% and have a significant impact on V-belt life.
While V-belts are most common, there are a couple of alternative belts that could be considered.
Note: Synchronous belts are toothed and do require installation of mating toothed-drive sprockets. Synchronous belts are noisy and may transfer vibrations. Care must also be used if synchronous belts are being considered for centrifugal fans. It is necessary to select the proper synchronous belt sprockets that account for absence of slippage; if not, operating costs could actually increase.
Always practice safety first when performing any maintenance. Check out these safety procedures for belt installation.