Winix Zero Air Purifier - £107.98 (membership required) @ Costco, Derby

Make sure you can find cheap replacement filters for any air purifier you buy or you'll be stuck with a useless box.

I've had one of these for about 1.5 years now, I think I paid about £160. I also have a Honeywell Air Genius 5 (had for approx 2.5 years). Between the two, I prefer the Winix, mainly because the Winix has an auto mode which dynamically adjusts the fan speed based upon current air quality. I also find the Winix more intuitive with a light on the front which is either blue (air quality is all good), amber (air quality can be worked on lol - but don't rush out of the house in a mad panic) or red (holy cow how is the air this bad, do I live inside a coal mine?)... With the Winix, I always know how good / bad the current air quality is with a quick glance. Comparatively the Honeywell has to go onto a fixed speed, by default this is 3 out of 5, and it has no indicator, light or other mechanism to inform me of the current air quality. This is both a waste of money (if the device is unnecessarily on a higher mode than needed and encourages excessive Ozone, which is generated at larger numbers when the device is on a faster mode. I do notice if I leave the Honeywell on speed 4 or 5, it starts to have a sort of 'burnt baked beans' smell which my friend informed me is Ozone). The Winix uses 'plasmawave' which is slightly different: see here for a super old school very American video from the manufacturer: youtube.com/wat…-dY

When it comes to bedtime, the Winix again is extremely intuitive, as it contains light sensors and detects when the room is dark. It automatically switches to night time mode, indicated by a tiny half moon light, when it does this all other lights go off. In terms of the filters, the Honeywell has a reusable / washable filter, and whilst I thought this was beneficial I have noticed with time the filter has started to warp in places, and despite all washing attempts it is brown and filthy. A huge bonus for me is the filters last a very long time and I don't have to worry about the filter getting dirty, warping etc like I do with the Honewell reusable filter.

To my recollection (and it is 1.5 years ago now, so I could have it slightly wrong), the Winix came with 4 spare carbon filters and 1 spare hepa filters. In the 1.5 years of ownership I have not gotten through all of the filters. If you follow the vendors replacement timeframes to the letter, I believe it comes with 2 years of filters out of the box.

I have noticed that Costco sell replacement filters and I do not expect they will stop selling them anytime soon (although I could be wrong). Costco have been selling this unit for a couple of years now and will have a UK customer base who need replacements. If you search on Costco for item 406926 it should come up. This is the main filter and 4 carbon filters. Doing the math, it should last a year, as the vendor recommends changing the carbon filter every 3 months and the main filter every year (Note: I have not double checked this but I'm sure I read it in the manual).

Brand wise, Winix is from South Korea and is quite popular in the United States. I used to live in Chicago and noticed plenty of people had these filters, hence, despite it being lesser known here in the UK, Costco have chosen to sell it.

Finally, the Winix always astonishes me with the amount of dust, hair, and other general particles it collects. When I go to clean it, compared to the Honeywell Air Genius 5, it really does contain a hell of a lot more grit and grime.

I have asthma and sleep apnea and this has helped me enormously. Prior to getting this, we had the Honeywell downstairs in the living room (doors kept open so it filters around). That definitely helped with my asthma and reduced my inhaler dependency massively. I added this to the upstairs landing, plugging it in outside my bedroom. Before bed I slide it into my bedroom (the cable reaches from the landing). I have considerable improvement in my apnea, namely I no longer have episodes so bad that I wake myself up several times a night. I have been informed that my snoring "is not that bad" whereas before my other half would roar at me for snoring so loud and give me the look of death at 7am daily after they were kept awake. On that note, my other half has circulation issues and always wakes up with swollen hands / calves. This has reduced a fair bit since we have the Winix in the bedroom.

Other Background: You enter our house from a courtyard, with the bedroom backing straight onto a fairly busy road. We have traffic lights just further down from us, hence traffic can back-up outside of our bedroom window. The first time I put the Winix on in the bedroom it was red. With it running on auto, I barely even hear it and it maintains the air quality without even being noticed. It occasionally goes to amber, automatically increases the fan speed to 2 or 3, and then settles itself slowly back to a whisper.

Any info on warranty? i don't see it on Costco website.