Review on 🌬️ Winix A231 Tower H13 True HEPA 4-Stage Air Purifier: Efficient Home/Office/Nursery Solution, White/Charcoal Grey Small by Kayla Watson

I was impressed with my Winix HR900 which I have in my living room and I bought it hoping it would be a smaller version for the bedroom. Unfortunately, it's nowhere near as good as the HR900. First, unlike the HR900, it doesn't automatically go into sleep mode. You have to turn it on manually every night, which is annoying. Accordingly, it is significantly louder than the HR900, despite being smaller and emitting less air - even in low mode. In fact, this model subjectively sounds louder at low frequencies than the HR900 at high frequencies. I could set the HR900 to medium while sleeping, but even the low volume on this model is too loud for comfortable sleep. It seems that this device was developed by a completely different team than the HR900. I suggest looking at the "rectangular" Winix units and going to the "cylindrical" models.