Quick take
Arros 9 fits smaller homes, Arros 15 is the mainstream larger-home option, and Arros 22 is for high-flow residential/light-commercial demand. Choose from validated flow at the dose target, not the model number alone.
Arros 9
VIQUA lists 9 GPM at 30 mJ/cm², 7 GPM at 40 mJ/cm² and 33W power consumption.
Arros 15
The 15 model is rated 15 GPM at 30 mJ/cm², 12 GPM at 40 mJ/cm² and 46W power consumption.
Arros 22
The largest model is rated 22 GPM at 30 mJ/cm², 16 GPM at 40 mJ/cm² and 60W power consumption.
Who should move up a size
Large showers, simultaneous fixture use, future additions or a calculated peak close to the smaller system limit are all reasons to choose the next flow tier.