Viega’s Radiant Auto-Balancing System (RABS) gives users the ability to independently control each zone in the system, the company says. Balancing valves are not required and installers can commission as many as eight thermostats and 12 circuits per control unit. RABS achieves the desired temperature in each zone by analyzing the supply water temperature, each circuit’s return temperature and zone air temperatures where a wireless thermostat is used.