Rinnai water heater has very low NOx emissions
Rinnai’s Infinity low-NOx series of continuous-flow water heaters have been tested to below 20 ppm of NOx, with a net efficiency of 107.7%. Infinity KBM water heaters use pre-mix burners with downward firing. The burner system reduces the possibility of flame lift.
The turndown ratio of 13:1 enables a 58.4 kW output to be modulated down to 4.5 kW. Hot-water output is 1.3 l/min with a temperature rise of 50 K.
Units can be connected to a common header flue. A unit weighs just 28 kg. Built-in pump recirculation control can be used to add, for example, underfloor heating.
These water heaters can be used to boost the temperature from solar-thermal and heat-pump systems.