I use an Aranet4 in the living room. Mechanical ventilation in most homes in NL allows configuring a precise flow rate in cubic meters so I've found the breakpo

I use an Aranet4 in the living room. Mechanical ventilation in most homes in NL allows configuring a precise flow rate in cubic meters so I've found the breakpoint to keep it < 1000 ppm. I took it to the office one day and it measured 2000 ppm. It turned out one of the motors that brings in fresh air in the ventilation system had failed, I wonder if it would have been noticed without the meter. It's a great little device.