Air filtration and air purification systems in general when it comes to whole home HVAC filtration solutions is long in the tooth about what they do and don't do in addition to that what they truly do in terms of cleaning the air without producing negative things you don't want like Ozone (any amount of Ozone production is not good for you). It's very subjective. Alergy sufferers: There are no two people alike when it comes to alergies. Some are more afflicted than others. I did some looking at the Air Knight Brand you mentioned in your post, just due to the Ozone producing alone I would never offer a product like that. In addition to that they recommend that the system blower run continuously, also the cost to me sounds self defeative to this product for what is required to make it work as designed. There are better options than this in my opinion. electrostatic filtration: In my opinion they don't work and tend to be very restrictive when it comes to air flow. They must be cleaned really well in most cases by means of taking them apart and cleaning each individual layer. (too much fuss to be a long term solution) They work by creating 'static' to charge the layers of the filter. If you live in a humid climate like I do it would be very challenging to generate the static needed to work properly. (drier climates are far easier at producing static electricity.) Because air conditioning is performed by the moving of air (350 -400 CFM per ton) restricting air via a restrictive filter like an electrostatic filter is not worth the trouble that will ensue, not to mention the higher light bills. So what is one to do? This situation is best left to your service provider. There are good intermediate choices that work well for most people, that perform well under most circumstances. The home in question, your alergy concerns and the cost of maintaining the system have to all be considered. Air purification systems (aside from cost and actually doing what they claim) biggest weakness is maintenance. This is yet another reason it is best left to your service provider. It's good that you've started your research and are questioning things. Often times manufacturer's only state the positives of the products they've made.

Hello! I would like to buy an air purifier and I am between xiaomi mi air 3h and levoit core 300. I have a bad odour in the living room and I want to resolve this problem and also have a better air quality in the apartment. I understand that Xiaomi is not so silent...or I don't know. They both have + and - and I don't know what to choose. Also..in my country they have the same price. Can you help me to choose one?

I've used four different brands: Austin Air, Coway, Winix, and Vornado. The Austin Air is a powerhouse. It is shaped like a small ottoman or stool, somewhat industrial looking. The filter media contains various metals. I have the "plus" model filter which captures VOC's and can really handle some awful air quality situations. It is liveable amounts of noise on medium, and a loud low sound when on high. The air flow out of the unit is unidirectional and it might not work in the particular spot in the room where you prefer. Austin units are $500 or more. The filters are also pricey but last a long time. However this is the type of unit you need if you have heavily polluted air. The reason is the filtration media. It is a substantial unit. It is American made out of one factory in New York State. They offer excellent customer service as well. Coway and Winix are similar products. Both are good. Initial cost is low at $150-$250. You have to plan for filter replacement every 3-6 months at about $50 per replacement. Easy to maintain and live with. Some models have louder fans than others. Some models send clean air straight up, and others blow clean air out on a 45 degree or 30 degree angle. That's not adjustable, so you have to make your choice about your preference and then you're stuck with it. Read the Amazon reviews carefully, and you will find a model that you like. I picked up two round Vornado Cylo units because they were deeply discounted right before the holidays. So far, I love them. I have one in each corner of my studio apartment to take care of stagnant air flow. One is near the head of the bed and one is near the sofa. Because they're new, I don't know how soon I will need to change filters - the company suggests 6 months. The purchase price was about $110 each and the replacement filters are about $25. Best bargain out of all the different brands I've tried. So far I think both of these are working very effectively. My mom currently has my old Coway and Winix. They are a good fit for her home, but in my studio they were not the right fit for my space. In my studio I have an Austin which sits on the floor, and I wheel it out to the center of the room if its really a bad air day. I have the two Vornados in corners of the room. Most days I have the Austin on low or medium, and the Vornado's on low. Occasionally I'll need to turn the Austin on high for about an hour, then I can turn it back down. Honeywell is a good value, too. It's very basic, just a cabinet and a filter. You can't go wrong with those, as long as you are sure you are buying a True HEPA. Unfortunately in the whole industry, "HEPA" does not mean the same as "True HEPA." Look for "True HEPA", or, read through all the specs to see how it has been tested and certified.

I have had Blue Air for years. I have two large units that I bought to filter wildfire smoke. One upstairs, one downstairs. They are extremely highly rated. I bought two smaller units for my grandson's bedrooms at each of his parent's houses for the same purpose because he has asthma and the smoke is really bad for him. Last year, I bought several different Blue Air units for my grandson's small grade school their models that filter viruses. https://www.blueair.com/us/blog-all/health/air-purifiers-virus-and-bacteria.html Some models are sometimes available at Costco. These are the smaller units I bought for bedrooms: https://www.blueair.com/us/air-purifiers/blue-pure-211-plus/1695.html They have newer models with different features. I like the 211 because it has a cloth cover that catches dust before it even gets to the filters and you can remove and wash the covers, which I think saves on having to replace the filters as often.