American Services commercial HVAC services serving Jefferson County knows that many commercial and institutional facilities typically have more motors operating in their HVAC systems than most maintenance managers realize. Because these motors use so much energy, they are a great place for facilities managers to begin energy efficiency evaluations with a shift towards making a significant impact on facility energy use. By far the leading cause of energy inefficiency with HVAC system motors is a mismatch between the motor’s rated horsepower and the load it is driving. Most HVAC system motors are induction motors.
While these motors are efficient and reliable, their efficiency drops off significantly when they operate under part-load conditions. By properly matching motor horsepower to system load requirements and implementing a comprehensive monitoring system, operation managers can achieve major energy savings immediately, as well as adding to the longevity of HVAC components-in this case, internal motors.
Accomplishing this goal requires that facility managers conduct an inspection survey on HVAC system motors to identify those that are significantly oversized for the application. The goal of the process is to develop a comprehensive list of applications that use motors, including information on the motor horsepower, the load it is driving, and the age and rated efficiency of the motor. Detailed documentation of HVAC components will insure energy efficient operation
The focus should be on motors that are oversized or have exceeded their operating life expectancies. Replacing older, oversized motors with properly sized ones offers two benefits. First, matching the motor horsepower to the actual load improves the operating efficiency of the system. Additionally, changes in motor design have resulted in a generation of motors that have operating efficiencies 2-8 percent higher than older, standard motors. Coupled with the improved operating efficiency that comes from matching the motor horsepower to the load, the improvement in efficiency can provide a relatively quick payback for facilities.