the first filter i tried was the tcl brava.is one doesn't have an auto mode and doesn't have any air quality measuring. you just turn it on or off and you can set the timer for as long as you want, so i left it running on medium for 2h hours. here's the air quality data from saturday with no intervention. and here it is from sunday with the tcp breather running for 2h hours as all the other days the air quality improved while i was asleep. but with the filter running, the aqi went all the way down to zero and you can see exactly where i got up and kicked up a load of dust again when i got changed in the morning. later in the day when i had a nap and again wasn't moving around the room, the tcl filter got the air quality index all the way down to zero again and for a low cost device, i thought that was pretty impressive. the second filter i tried was by south korea's dynair and this one caught my eye because it used ultraviolet to kill airborne virus. it's very appropriate in these times. the machine has an automatic mode and bu