: For general household use, HEPA 12 or 13 is standard. Sensitive environments or medical-grade needs often require HEPA 14 .
: Look for "True HEPA" or "Absolute HEPA" on the label, which guarantees capture of 99.97% of particles at 0.3 microns . Be wary of "HEPA-type" or "HEPA-like" terms, which are unregulated . where to buy hepa filter
: Ensure the filter's Clean Air Delivery Rate (CADR) is at least 2/3 of your room's square footage for optimal efficiency . : For general household use, HEPA 12 or 13 is standard