Start with the problem you are actually trying to solve. Each guide sizes recommendations from AHAM Verifide or ENERGY STAR CADR data and states the air-change basis behind any coverage figure.
Room-size-specific picks using AHAM Verifide and ENERGY STAR CADR data, with noise and ongoing filter cost.
Read guide →Pollen, dust-mite allergen and dander — sized by actual air changes per hour rather than marketing coverage claims.
Read guide →Dander is a particle problem; pet odor is a gas-phase problem. What filtration actually addresses each.
Read guide →Smoke CADR, activated carbon capacity, and how to size for PM2.5 during an active smoke event.
Read guide →Cigarette and cooking smoke, and why carbon mass matters more than HEPA for the odor component.
Read guide →Budget units compared on verified CADR and filter running cost — not on list price alone.
Read guide →HEPA captures particles; activated carbon adsorbs gases and odors. What each does and when you need both.
Read guide →ASHRAE 52.2 E1/E2/E3 efficiency data, and how to judge what your specific system can actually accommodate.
Read guide →Deterministic calculators — no account, no email.
Identifies whether your problem calls for filtration, source control, ventilation or humidity correction — then points to the right next step.
Open tool →Required CADR from room volume and your target air changes per hour, with every assumption shown.
Open tool →MERV category guidance by filter size, depth and problem — with a compatibility warning when your system limit is unknown.
Open tool →AirFilterGeek is a participant in the Amazon Services LLC Associates Program. We may earn a commission when you purchase through our links, at no extra cost to you. Product rankings are not for sale.
How these guides are researched: About / How We Evaluate.