HVAC systems in most commercial buildings account for more than 40 percent of the total energy use. Maintaining properly running HVAC systems at peak efficiency is crucial in managing and saving energy use. Good HVAC system maintenance is not only important in controlling energy use but also for the proper operation of the systems at people convenience. For instance, most of the telecommunications systems require specific environmental conditions for proper operation. At times, temperature and humidity levels fall outside the specified range, leading to costly system failures and interruption in services. Therefore, proper HVAC system maintenance is key to the running of most businesses.