Airmega 300 (model 300)

Yeah, your boyfriend is totally wrong. KNKA appears to be a junk rebadged brand. These are typically very cheap with poor build quality, short-lived replacement filter availability, and lousy customer service. The 2,325 sq. ft. coverage rating is highly misleading. This is likely at 1 Air Change per Hour (ACH) which is far too low. You want a minimum of 4.8 - 5 ACH for relatively normal particulate pollution levels. Biggest red flag: no Clean Air Delivery Rates (CADRs) listed. Coway is a high quality consumer-grade brand. The [Airmega 300](https://cowaymega.com/products/airmega-300?variant=34493568647327) has a 5 year warranty, is energy efficient, and relatively quiet. Top Smoke CADR is 285 CFM. This means the largest room size it can handle is 427 sq. ft. with an 8 ft. ceiling. You can use the discount code **COWAYMEGA10** on Coway's website for an additional 10% off, which brings the price down to $398.70. Unfortunately neither of these will combat the chemical odors from lawn care treatments. Odors are gases or vapors which require many pounds of sorbent media. Sorbent media are activated carbon, activated alumina, or synthetic zeolites. Neither the KNKA nor the Coway have very much activated carbon; they are designed to capture particulates (such as airborne mold spores). Heavyweight sorbent media purifiers are very expensive, very loud, and clean the air more slowly than particulates-focused purifiers. An entry-level unit from a brand like AllerAir would be at least $600. And depending on the exact gaseous "species" you're smelling, you may need chemically modified sorbents to enhance removal capacities.

FYI: Air purifiers can't overcome walls or doors. You would need one for each room. (It sounds as though the 500 sq. ft. is fairly open, but I don't know if that includes a walled-off bathroom.) That being said, multiple purifiers can capture pollutants closer to the source and increase air circulation. The recommendations from others here are a bit off. Some models (if you were to buy just one) do not have adequate Clean Air Delivery Rates (CADRs). You should follow the [AHAM 2/3 rule](https://ahamverifide.org/ahams-air-filtration-standards/) for CADRs as mentioned in the AutoModerator comment and in our "How To Choose An Air Purifier for Particulates \[Comprehensive Guide\]", specifically ["CADR Particulate Types and Sizing"](https://www.reddit.com/r/AirPurifiers/wiki/index/how_to_choose_an_air_purifier_for_particulates/#wiki_cadr_particulate_types_and_sizing). For a continuous 500 sq. ft. space, **the minimum CADRs ought to be 334 CFM**. If someone has allergies or sensitivities, CADRs should probably be even higher. A single [Levoit EverestAir](https://levoit.com/products/everestair-smart-air-purifier) ($499.99) meets minimum CADRs for all particulate types. A single Winix 5510 or Coway Airmega 300 do *not*. **However, you** ***can*** **buy multiple air purifiers to ensure minimum CADRs are met or exceeded. You haven't listed a budget per se, so I don't know how much you want to spend.** Generally, we tend to recommend Coway purifiers first for their build quality. Their best units are usually the Coway Airmega 240, Airmega 300, Airmega 400, and Airmega ProX. Keep in mind the CADRs listed for purifiers are for the highest airflow/speed setting only. Lower settings have lower CADRs.

No, Dyson is one of the worst! The HP09 has terrible Clean Air Delivery Rates (CADRs). They just know how to market effectively. As **Rule 4** and the AutoModerator comment repeats, it's helpful to know the ceiling height. I'll assume it's 2.4 meters. 60 m^(2) x 2.4 = 144 m^(3). For rooms measured in meters, CADR should be at least 3 times a room's volume (in m^(3)). So the minimum CADR should be 432 m^(3)/h. If you have [allergies, health conditions, high pollution, etc.](https://www.reddit.com/r/AirPurifiers/wiki/index/how_to_choose_an_air_purifier_for_particulates/#wiki_when_higher_than_normal_cadrs_may_be_needed), multiply the room's volume by 4-6. So CADRs of 576 - 864 m^(3)/h. Coway is a high quality brand that's relatively quiet. I don't know exactly where you are, so I don't know what's available to you. But the [Coway Airmega 400](https://www.amazon.co.uk/purifier-restaurant-certified-HyperCaptive-filtration/dp/B099S9Y285) would be a very good fit (Amazon UK website linked). If you can't find that, the Coway Airmega 300 might suffice... although you may want to supplement it with a smaller Coway model like the Coway Airmega Jet.

coway. coway hands down. with two cockatiels i keep one thats supposed to cover 2500 sqft in a tiny bedroom because well…. it requires it, but we want a second one for the rest of the house. they do purifying and have charcoal filters for odors which has been great for cooking etc in the past

I have a CR box with 6 PC fans. The throughput is just not enough to deal with the fire smoke.. ended up turning my actual purifier’s fan speed up. I have the Coway 300. Speed 3(200CFM) worst day 2 of them running.

The machine does a slow ramp up and down when you change speed.. my thought is when you are at speed 2 and you want to change to speed 1, you have to change through 3 and 4… and 3 and 4 are fast and noisy(I use 3 normally at day time). A “delayed” changed can be helpful.

Oooooooh interesting… I really thought 300 and 400 are the same except bigger.. I only have 2 of the 300

Get the Coway Airmega 240. Its on sale and should be around the 1512 price and it's more powerful. You want to oversize it so you don't have to run at max speed. If you got the space and money the Airmega 300 is a nice unit also. Blue air is garbage!

Nice. I own the Airmega 300 and 400. They're probably my favorite units I've owned over the years.

I have two of those for bedrooms and the bigger airmega 300 for kitchen/dining/living area. They've been working great for me (I get impacted by wildfires and my neighbors fireplaces).

Get whatever coway is on sale, I like the 240/250/300/400