There is a revolution happening in today’s plumbing marketplace, specifically when it involves domestic hot water system designs. Manufacturers are supplying today’s better performing digital mixing valves stacked with features and enhancements that carry the capabilities of remote temperature adjustment, high temperature sanitization, building management system integration, multiple temperature and pressure measurement points, flow measurement, self-cleaning, self-monitoring and self-balancing. These features, along with the parallel capabilities and advances in digital smart circulator pumps for these applications, are allowing building designers and specifying engineers to think about the domestic hot water system in ways never previously imagined.
In the past, conventional mixing valve technologies such as Bellows, wax or Bi-metal would simply allow the end user to set the temperature at initial flow condition. These systems allowed no active monitoring of upstream (inlet) or downstream (outlet) temperatures or pressures. The balancing of the recirculation system was accomplished by an iterative process of manually throttling a return ball valve or circuit balancing valve on the return line based on a fixed temperature loss in the system. Typically, in these systems, it would take multiple iterations over a period of days to stabilize system temperatures under pure circulation. If system conditions experienced even slight variations in temperatures or pressures, facility managers were faced with reactionary tactics in the face of no active feedback loops or data that could be served up from the device.