True HEPA Air Purifier
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Mid-Range, Great Purifier

The GermGuardian AC4825 is a moderately priced purifier that delivers beyond its price range. It includes a true HEPA filter, a UV-C light, and is suitable for small to medium sized rooms under 150 square feet.

100+ CADR

The Clean Air Delivery Rating (CADR) in this unit is upwards of 100; since you should seek to have CADR ratings that are about 2/3rd the room size you are looking to use the purifier in, this model is ideal for rooms about 150 square feet or less, making it a suitable purifier for small to medium sized rooms.

Replaceable filters

The GermGuardian AC4825 comes with replaceable filters. While the filters for this model are slightly pricey, you can choose to buy generic charcoal filters to defray some of the cost. You will want to replace the filters about twice per year, so consider this cost when budgeting for this purifier. The benefit of replaceable filters is that it will help the purifier continue to run like new for years.


True HEPA filter

The GermGuardian AC4825 is one of the few models in its price range with a true HEPA filter. HEPA filters are guaranteed to remove air particles as small as .3 microns with 99.97% accuracy and are overseen by the US Department of Energy. This makes the GermGuardian AC4825 one of the best mid-range models for allergies and asthmatics, as it will remove the smaller mold spores, pollen, and dust mites that aggravate the respiratory system.

UV-C light

The UV-C light on the GermGuardian AC4825 kills viruses, mold spores, and airborne bacteria. It can be turned on or off if the light bothers you at night. The UV-C light also activates titanium dioxide to further dissolve smoke, food, and pet odors.

3-in-1 cleaning system

The GermGuardian AC4825 uses a pre-filter to trap large particles before air is filtered through the HEPA filter, which will remove most particles as small as .3 microns. A final charcoal filter (containing carbon) absorbs gasses and odors before the purified air is circulated back into the room.

Activated carbon

The activated carbon filter in this unit removes odors and gases without using ozone or ionization, which can irritate some users and may be associated with health risks. While there is no positive evidence of ozone emitting deodorizers being risky to health, it is a much debated topic in the healthcare community. Carbon does not pose any health risk and the GermGuardian AC4825 does not emit any chemicals or molecules into the air.



This model is not an ultra-quiet purifier and will produce a noticeable noise, especially after the first few days of use. The low setting should be fine for anyone who can sleep through some quiet white noise, but the higher settings do make it hard for light sleepers to sleep through.

Overall Review

The GermGuardian AC4825 is one of the top-performing purifiers in its price range. While the noise level may be inhibiting for some users, most will appreciate the noticeable difference in air purity produced by this model. The true HEPA filter is a rare find at this price point and one of the GermGuardian AC4825’s greatest benefits.