Fairwind Home was started by two brothers, Tom and Michael Ward, who grew up in a damp rented house in the north of England and spent their childhood on inhalers. Nobody told them the air indoors was the problem. They worked it out thirty years later, with a sensor.

What they found when they started measuring wasn't a technology problem. It was a marketing one. Every box promised the same thing and almost none would show you the number.

So we publish what most brands leave off the box: the noise at the setting you'll actually use, the real room size rather than the flattering one, how long a filter lasts. We sell an air quality monitor alongside the purifiers because we would rather you checked our work. If we can't back a number, we don't print it.

This is for the household where someone still wakes up coughing, and who would rather see evidence than be sold another promise.

Start with the monitor if you want proof first, or the bedroom purifier if you already know your nights.