What role do filter gauges play in a Building Management System (BMS)?

Filter gauges are essential components within a Building Management System (BMS) primarily because they indicate pressure differences across filters. This measurement is critical in assessing the condition of air filters in HVAC (heating, ventilation, and air conditioning) systems. When air passes through a filter, it collects dust and other particulate matter, which can cause a buildup that increases pressure drop across the filter.

By monitoring the pressure differences, building operators can determine when filters need to be cleaned or replaced. This proactive maintenance helps in maintaining optimal air quality, improving the efficiency of the HVAC system, and reducing energy consumption. Additionally, it prevents the system from working harder than necessary, which could lead to premature equipment failure.

Other choices do not accurately reflect the function of filter gauges. They do not measure external air quality, control refrigerant flow, or monitor energy consumption directly, making the indication of pressure differences across filters the primary and correct role of filter gauges in a BMS.