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GermGuardian AC4825 3-in-1 HEPA Air Purifier

GermGuardian AC4825 3-in-1 HEPA Air Purifier Review

HEPA air purifiers can be pretty expensive. That’s because most of them are designed to clean air in large rooms, some up to 1,000 square feet.

If you need an air purifier for a small room, a smaller and cheaper air purifier will work just as well. We recommend the GermGuardian AC4825 HEPA Air Purifier.

It’s cheaper than most HEPA air purifiers and covers a smaller area as well (up to 167 square feet). This makes it ideal for bedrooms, home offices, apartments, and even RVs and boats.

The GermGuardian AC4825 uses a 3-stage system to remove up to 99.97% of pollutants and allergens from indoor air.

Keep reading for our full review.

If you are looking for a more powerful HEPA air purifier you can use in a larger room, read our HEPA air purifier buying guide for top recommendations.


  • Very affordable.
  • High-performance 3-stage air purification.
  • The integrated UV light kills bacteria and viruses.
  • Three-speed settings.


  • Not ideal for large rooms.
  • Noisy when the fan is set at the highest speed.

Best Features 

GermGuardian AC4825 3-stage Filtration

1. 3-stage Filtration 

The GermGuardian AC4825 HEPA Air Purifier is designed to tackle a wide range of allergens and pollutants including pollen, dust, smoke, pet dander, odors, and airborne pathogens.

It does this using three filters.

Pre-filter + charcoal filter: Captures larger particles like dust, pollen, and pet hair. The pre-filter also protects the HEPA filter from clogging, thus making sure it lasts longer before you need to replace it.

HEPA filter: Captures fine allergens like pet dander, mold spores, and dust mites.

UV-CKills airborne pathogens, including bacteria and viruses. Note that you can turn the UV-C light off.

For air purification, the Germ Guardian AC4825 strictly has only two filters. The UV-C light does not target allergens.

While the two filters are enough for most homes, the air purifier may not be as effective if there’s a high level of pollutants in your home.

For instance, if there is a wildfire near your home.

If you are looking for an air purifier to get rid of heavy smoke or high levels of dust, you should probably get a more powerful air purifier.

But for mild to average levels of allergens and odors, the Germ Guardian AC4825 is perfect.

2. Ideal for Small to Midsize Rooms 

The GermGuardian AC4825 HEPA Air Purifier is rated for rooms up to 167 square feet. It’s more ideal for the bedroom, nursery, or home office rather than your open plan living area.

It’s also ideal for small apartments, RVs and boats.

If you want to use it in a large room, we recommend getting two or three Germ Guardian air purifiers and placing them strategically around the room.

3. Three Speed Settings Plus Filter Indicator

The control panel on the Germ Guardian AC4825 is one of the simplest we’ve seen. Just a UV-C button and a dial to control fan speed.

You can choose from three fan speed settings. The highest level provides the quickest air purification, but it’s also the noisiest. It’s as loud as a desk fan.

The lowest level is ideal for night use. It purifies air slower but is almost completely silent.

Another feature on the control panel is a small light that flashes red to indicate that you should replace the filter.

Replace the two filters every 6-8 months and the UV bulb every 10-12 months.


germguardian air purifier

The GermGuardian AC4825 is designed for small rooms and low to average levels of pollutants and allergens.

If you use it in a room larger than the recommended max, it will clean the air too slowly to be useful, especially for people with allergies or asthma.

It can also get overwhelmed if there are a lot of pollutants in the air, such as wildfire smoke. Some users had to run the air purifier on high for a couple of days to notice a difference in their indoor air.


Dimensions: 9 x 5.5 x 22 inches

Weight: 7lbs

Coverage: 167 square feet

Number of filters: 3

Ionizer: no

Filter life indicator: yes

Auto mode: no

Fan speeds: 3

Air quality indicator: no


GermGuardian HEPA Air Purifier

Getting a $500 air purifier for your small bedroom or home office is overkill. The compact GermGuardian AC4825 will do the job just as well for way less money.

About the Author Tom Hanson

I’ve worked as an HVAC tech in Phoenix, AZ for the past 10 years. I created to help home owners select the right portable air conditioner, cooler or air purifier for their needs & budget in just a few minutes.

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