Is the GermGuardian AC4820 good for a large room?

It is best for bedrooms and medium rooms. Its smoke CADR is 99, which is low for the 743 sq. ft. per hour circulation figure, so a big open space will take a long time to clean.

Which filters does it use?

It takes the GermGuardian HEPA Filter B (FLT4825 series) and carbon filter FLT22CB4. The filter change indicator tells you when to swap them.

How loud is it at night?

The lowest of the three speeds is ultra-quiet and many owners use it as white noise. Higher speeds are clearly audible.

Does it produce ozone?

No. It is ozone free and verified zero ozone, and it uses no ionic filtration.

Is $79.99 a good price?

That Walmart price as of November 7, 2026 is at the low end of its recent range, with three stores listing it new. Factor in the cost of replacement filters.

What comes in the box?

The purifier ships with a HEPA filter and carbon pre-filter installed. Check the listing for any spare filter included.

GERMGUARDIAN Tower Air Purifier with HEPA Pure Filter AC4820

Q: Where is the GERMGUARDIAN Tower Air Purifier with HEPA Pure Filter AC4820 cheapest?

At Walmart, for $79.99, as of our latest check.

Q: What do buyers say about the GERMGUARDIAN Tower Air Purifier with HEPA Pure Filter AC4820?

Rated 4.5 out of 5 from 1,033 ratings.

Q: Where can I buy the GERMGUARDIAN Tower Air Purifier with HEPA Pure Filter AC4820?

4 stores we checked sell it, including eBay, Walmart, Best Buy, Guardian Technologies.

Best price now

$79.99at WalmartObserved at 10:42 PM

Compared across 3 stores. Prices are checked against each store and labelled with when.

Visit Walmart

What reviewers say

4.5 / 51,033 ratings

Rated 4.5 out of 5 from 1,033 ratings, the AC4820 is generally well liked for quiet operation and noticeable relief from dust, pollen and pet dander. Complaints center on filter replacement cost and on the unit being smaller in reach than the coverage claim suggests.

What people mention

NoisePraisedOwners say the low speed is close to silent and works as white noise at night.
FiltrationPraisedReviewers report less dust and fewer allergy flare-ups after running it daily.
Filter costCriticisedBuyers complain that genuine HEPA and carbon replacements add up over time.
CoverageMixedSome find it fine for a bedroom but too slow for the advertised large-room coverage.
BuildPraisedThe slim tower is described as sturdy and easy to place against a wall.

About the GERMGUARDIAN Tower Air Purifier with HEPA Pure Filter AC4820

Purify your space with confidence. The GermGuardian AC4820 22" Tower Air Purifier circulates and cleans the air in rooms up to 743 sq. ft. per hour, making it an ideal large room air purifier for bedrooms, living rooms, and open spaces. Featuring True HEPA Pure protection, it captures 99.97% of dust, smoke, pollen, and pet dander as small as 0.1 microns*, helping reduce allergy and asthma triggers for healthier breathing. With 3 speed settings and whisper-quiet operation, this HEPA filter air purifier doubles as gentle white noise at night, making it one of the best air purifiers for bedrooms. A pre-filter and activated carbon layer trap larger particles and neutralize odors from pets, cooking, and smoke for fresher air. For lasting performance, use only genuine GermGuardian replacements: HEPA Filter B (FLT4825 series) and carbon filter FLT22CB4. Designed and performance-tested, GermGuardian has been trusted since 2005 to deliver cleaner air you can count on. *Initial efficiency value. As small as 0.1 microns from air passing through the filter media.