If you're looking for an air purifier, I recommend this one — I've used it for 3 years and it's still great, at only 11,900 baht. It's an air purifier with a washable filter, so no replacements, no buying new filters — just take it out, wash it with water, dry it, and put it back in for reuse. It filters dust really well, super fine. It's a Chinese-brand model; an American-brand model would cost many times more. Connects to Wi-Fi so you can control it from your phone, and you can set a timer. I've had it running continuously 22 hours a day for 3 years and it still works great. I take the filter out to wash it once a month to keep it clean.