I've been thinking about getting an air purifier for a while. Dust really bothers me, especially when I vacuum. I make my wife empty the vacuum because if I do it, I will suffer for the rest of the day. I summer from hayfever, and recently my wife has been complaining about it as well. Researching for a few weeks, most great looking models are not available or several times more expensive in the UK like the Coway AP-1512HH Mighty, which sells everywhere in the US, including Walmart for 200 USD. Some research tells me: High airflow True HEPA filter Active charcoal filter Washable dust filter affordable replacement filters Some models I've found that don't break the bank: Mi Air Purifier 3H electriQ EAP500HC 7 Winix Zero VAX 300 Philips AC2889/60 (if on a good sale maybe). I haven't had much luck finding advice regarding UK models. Most sites I've found lists containing several models, say they are all amazing and provide affiliate links. Some good information on youtube, but almost exclusively for the US. It also seems that Amazon has a limited selection for what is available from other sites I've never heard of (appliancesdirect and activeaircontrol). I would prefer to not spend over £300 and an air purifier is basically a fan with a couple of filters strapped to it. Smart sounds great, but I've heard the sensors are a bit rubbish.
I can't vouch for any home units as I have 0 experience. However -- fans and filtration are my thing. To confirm: High airflow - pretty high on the list. For good airborne control you are looking for around 10-12 air changes per hour (this is based on fresh air and not re-circ, however with a HEPA we can call it fresh for dust purposes). In a unit of this size, you are going to be well under that - however the higher airflow you can get the better it should be. The main way these units work is by diffusion, same as hospitals. You want to get as much clean air into the room, which mixes with dirty air and 'thins it down'. Think of adding 10L of water to 10ml of squash. Bear in mind that a better ventilated area, such as a corridor or hall with outside door will be very difficult to clean with one of these units. By the time it has 'cleaned' the air, you will have opened a door/wind will have blown past it etc (for example a normal, unsealed house door will easily flow 30L/s) True HEPA filter - requirement in my opinion (for dust/pollen). Not all HEPA's are made the same, good ones are expensive and will load up fairly quickly. HEPA's are pretty restrictive as they are, and once loaded their resistance goes through the roof pretty sharpish. If you leave one too long, you will have lost enough flow for it to not really be doing its job anyway. Active charcoal filter - Also good at getting 'stuff' out of the air, mainly things like VOC's and other chemically smells. If you are just looking for dust/pollen reduction, I wouldn't say a charcoal filter is a requirement. Washable dust filter - If you can, getting one with a U4 to U7 washable filter (unsure if they spec filters by U number - they should) is a great idea as it really keeps the loading on the HEPA to fine particulate, which means it will last much longer. As I say, bear in mind whilst they say 'this filters and purifies the air in your room' it actually means they grab some air, filter that, and diffuse the rest of the dirty air. Having a window cracked open, a leaky door, direct air brick, etc, will severely limit the capability of one of these units.
I went for a Dyson Pure Hot+ Cold Link, Because I wanted one I could use as an actual fan while I sleep, they're basically one of the quietist fans out there and my room gets super cold in the winter so the heating functionality is a bonus. I grabbed a refurbished one on ebay (from the dyson outlet) For £350 and it has a 1 year warrenty. Its actually fairly good, its a great heater (you can schedule it using the app so I could fire it up in the morning to warm my room up). As for purification, its trick to know. I think my room is less dusty than before. Oh, and I run it on diffuse mode, so the only air coming out of it is the purified air. You can run it on focused mode, where the air multiplier takes effect, but then obviously the air will be less pure.
