Airmega 450

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 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

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