Airmega 450

I wouldn't focus on coverage ratings, as brands like to inflate them. With a big number like 1,700 sq. ft., this is probably at 1-2 Air Changes per Hour (ACH) which is too low. Generally you want a minimum of 4.8-5 ACH. Even so, the more important metrics are Clean Air Delivery Rates (CADRs). And ye

Going by the AHAM 2/3 rule, your 15' x 15' x 10' bedroom needs minimum Clean Air Delivery Rates (CADRs) of 188 CFM. The Coway Airmega 250S can achieve that, although I don't know if you have allergies, high pollution levels, or other circumstances that need increased CADRs. The Coway Airmega 450 doe

I assume the 500 sq. ft. you mentioned in another comment is an open space without walls. (You need a purifier for each room, as they can't overcome walls and doors.) If the 500 sq. ft. is open, you would need a minimum of 334 CFM CADRs. These figures are for normal pollution levels. You may have el

With dust mite allergens, you can try reducing relative humidity (RH) below 50% for a prolonged period. (Another study recommended RH of 45% or lower if I recall correctly.) This should kill them off. For the bedroom: of the two, I would tend to choose the Coway Airmega 350. You'll definitely need t

I assume you're an expatriate living in the US? Most Americans don't use "whilst". 😉 Unfortunately if you have high levels of particulates (pollen, dust, mold, etc.) and gases/vapors/odors (including VOCs), you generally need two types of air purifier. This is because particulates-focused purifiers

You won't reduce visible dust with a conventional HEPA purifier unless you buy multiple hugely oversized units. This would be loads of money. Visible dust is large and heavy compared to "invisible" pollutants like PM10, PM2.5, and PM0.1. See the sticky post at the top of this subreddit. Our FAQs pag