Overall score for the IQAir HealthPro 1BAUA0CGU is mainly how well the model removed dust and smoke from a test chamber, plus quietness for room purifiers and airflow resistance for whole-house units.

Air filters aren’t the sexiest of appliances. The family-run air conditioner startup Windmill hopes to change all that.

I used a Temtop Air Quality monitor to check how high PM 2.5 levels in the bathroom went, turning on the air purifiers for smoke once they were more than 250. I also tested for the IQ Air Atem in my ...