Choosing a Portable Air Purifier
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Quick answer: Choose one with a clean air delivery rate (CADR) large enough for the room (EPA). For smallest particles, look at the tobacco-smoke CADR. Many use a HEPA filter; activated carbon targets gases. Avoid units that intentionally produce ozone (EPA).
⚠ Safety first:
- Turn the system off at the thermostat before opening the filter slot.
- Gas furnace? Have working carbon monoxide (CO) alarms. CO is colorless and odorless (EPA); if a CO alarm sounds or you feel headache, dizziness or nausea at home, get outside and call 911 or your gas utility.
- EPA recommends a trained professional inspect, clean and tune up furnaces, flues and chimneys every year.
Steps: easiest & free first
- Measure the roomFREE
Length × width = square feet; compare to the max room size on the package (EPA). - Match the CADRFREE
EPA’s chart (8 ft ceilings): 100 sq ft → 65 cfm, 200 → 130, 300 → 195, 400 → 260, 500 → 325, 600 → 390. Go higher for tall ceilings. - Pick the filter typeSHOP
HEPA for particles; activated carbon for gases and odors (EPA). - Skip ozoneFREE
Avoid ozone generators; ozone is a lung irritant (EPA). - Run it on higher speed, longerFREE
Higher speeds and longer run times filter more air (EPA). Replace filters as directed.
⚠ When to call a pro: a CO alarm goes off; you smell burning, gas or electrical odors; the furnace short cycles (turns on and off rapidly) or overheats after a filter change; ice on the A/C coil; or you want a higher-MERV filter and aren’t sure your system can handle it (EPA suggests asking an HVAC technician). Have a pro tune up the system each year (EPA). Renting? See what you can fix vs. call your landlord.
Helpful supplies
| Item | Why | |
|---|---|---|
| HEPA portable air cleaner | Sized by CADR for your room (EPA) | Check price [PLACEHOLDER – no affiliate link] |
| Replacement filters | All filters need regular replacement (EPA) | Check price [PLACEHOLDER – no affiliate link] |
Generic categories only; check the product label and your home’s needs before buying.