GermGuardian AC4825 3-in-1 Air Cleaning System

GermGuardian AC4825 3-in-1 Air Cleaning System is very popular and affordable, home air purifier. It features simple-to-use controls, true HEPA air filter combined with mechanical air pre-filter and activated charcoal layer and UV-C lamp with titanium dioxide.

GermGuardian AC4825 3-in-1 Air Cleaning System efficiently purifies air in medium size rooms and removes odors, airborne allergens, dust etc.

Published: March 1, 2019.

germguardian ac4825 1

GermGuardian AC4825 dimensions are 5.5 x 9 x 21.5 inches (~14 x 23 x 55 cm) and it weighs around 7 pounds (~3.2 kg). It's is very stylish unit that can easily fits in any room, regardless of the room's decors and design.

GermGuardian AC4825 3-in-1 air purifier comes with 6 feet (~1.8 m) long power cord and it requires ~1 feet of free space around the unit to operate properly.

Although it is very simple air purifier to operate, before the very first use it is highly recommended to check the manual first.

GermGuardian AC4825 Air Purification System

GermGuardian AC4825 3-in-1 air purifier combines three systems (hence the '3-in-1') to purifier air:

- mechanical air filter, which is combination of (again) three filters in one. Mechanical pre-filter removes larger dirt like human and pet hair, lint, fibers and similar, activated charcoal filter removes odors and certain chemicals from the air, while true HEPA air filter filters out and retains 99.97% of 0.3 microns and larger particles of various air pollutants like dust, pollen, mold and similar.

germguardian ac4825 filters

Mechanical pre-filter, activated charcoal layer and true HEPA air filters are combined into one replaceable air filter, which significantly simplifies the unit's maintenance. Also, there are actually two types of air filters:

- FLT4825 Filter-B True HEPA GENUINE Replacement Filter,

- FLT4850PT Filter-B-Pet True HEPA GENUINE Pet Pure™ Replacement Filter.

The only difference is that FLT4850PT Filter-B-Pet filter comes with additional 'Pet Pure' treatment, which is basically an antimicrobial agent added to the filter to prevent the growth of mold, mildew and odor-causing bacteria on the filter surface. Since actual price between these two filters is just few dollars/euros, if you can, go for OEM's FLT4850PT Filter-B-Pet air filter.

Regardless of the filter type, air filter should be replaced every 6-9 months, depending on the usage.

- UV-C lamp irradiates filtered air and kills remaining airborne germs and bacteria.

- UV-c lamp activates titanium dioxide (TiO2) layer which reduces certain odors and chemicals in general.

CADR rating is 100+, which is rather good result for achieved air purification level and the price of the unit. AC4825 air purifier is recommended for rooms up to 155 square feet, although it can be used in larger rooms, too, but with somewhat decreased level of air purification (or get a pair of them).

GermGuardian AC4825 Controls

germguardian ac4825 controlsGermGuardian AC4825 controls are very simple, since the unit doesn't feature WiFi, and it is not Amazon Alexa or Google Assistant compatible unit.

Nonetheless, one of the reasons why GermGuardian AC4825 is so popular unit is in its simplicity - to turn the unit on, rotate knob found on the top of the unit clockwise.

There are three fan speeds: Low, Medium, and High - they are set using the same knob.

UV-C lamp comes with its own UV button - if desired it can be left turned off, while air fan operates.

Note that GermGuardian AC4825 features 'Change Air Filter' and 'Check UV Lamp' indicators - they both can save the user some money and plenty of time.

Note: there are non-OEM air filters and other parts on the market, but quality of released air depends on the quality of used filters and with OEM filters, one is sure that the quality is there. With non-OEM filters and parts, one can never be sure ... And the amount of saved money, IMHO, does NOT justify the use of non-OEM filters and other parts.


For Short: Although AC4825 is relatively cheap unit, it does its job very well. Air filter should be replaced every 6 to 9 months, but considering the price of the air filters, maintenance costs are also rather low.

If you need a good and affordable air purifier, suitable for medium size room and easy to use, consider GermGuardian AC4825 unit.

For more reviews and recommendations and most up-to-date offers and prices, check GermGuardian AC4825 3-in-1 HEPA Air Purifier Amazon link (link opens in the new window).