Air Purifier Reviews, Budget

GermGuardian AC4825 Air Purifier Review

GermGuardian AC4825 Air Purifier Review

The AC4825 air purifier is GermGuardian’s best-selling machine. It’s also one of our favorites. The GermGuardian AC4825 is among the most efficient compact air purifiers on the market, featuring a sleek modern design that is portable and will blend in anywhere. It handles everything from dust to cooking odor, and is also great for users suffering from asthma and allergies. Best of all… it’s very, very affordable.

Guardian Products

Guardian Technologies, founded in 2002,  is an Ohio company that specializes in home sanitation products with an emphasis in providing top notch products at a great price point. Some of their products include air sanitizers, ultrasonic humidifiers, vacuums, and water filtration technology.

RELATED: Germguardian AC5250pt Review. 

Editor’s note: We originally published this article in February of 2015. However, since we still love this unit we thought it deserved an update. So, we completely revised the original article for accuracy, relevance, and in consideration of new developments in purifier technology. 

Features and Technology

The AC4825 is the best value product in Guardian’s line of air purification systems. It also competes well with units costing 2 to 3 times as much. This earned is a top spot in its class, as few other air purifiers offer as much quality for the price that GermGuardian does. This machine features multiple purification technologies that scrub the air clean no matter what ventures into its path.

3-Level Filtration System

Guardian designed the AC4825 as a multi-purpose machine that incorporates three levels of filtration to target a wide spectrum of airborne pollutants.

GermGuardian Filter Technology

2-In-One Pre-filter With Activated Carbon

Pre-filters are becoming are great. They protect a unit’s HEPA filter from large contaminants, allowing HEPA to tackle things as small as 3 microns. The pre-filter allows the machine to run more efficiently and also extends filter life.

The 4825 also combines its pre-filter with a layer of activated carbon to reduce odors. Activated carbon is a unique material that removes odors due to its incredibly porous structure. Chemicals, VOCs, and odors will sneak through even the best HEPA filter. But, activated carbon will tackle smoke, pet odor, and kitchen funk with ease.


True HEPA Filter

High Efficiency Particulate Arresting (HEPA) air filters are the most effective means of filtering out the vast majority of airborne pollutants from your home. HEPA filters contain millions of fibers that trap pollutants inside the filter. HEPA filters are also the only filters standardized by the United States government. To earn the title the must be effective at removing 99.97% of particles larger than 0.3 microns.

It’s important to note that some of GermGuardian’s competitors switched to low quality HEPA-type filters to cut costs. However, GermGuardian has kept true HEPA filters in their machines keeping them a step ahead. That’s a huge plus in our book.


GermGuardian True Hepa Replacement Filter

GermGuardian True Hepa Replacement Filter available on

UV-C Air Sanitizer

The GermGuardian uses ultraviolet light technology as the last step of its filtration process. Manufacturers claim that this technology is effective at killing bacteria and viruses like E.coli and rhinovirus. It’s debatable how effective this can be, but it is nice that they include it and give you the option to turn it off if you prefer. We did a full write up that explains where we stand on the matter.

Suitable Applications

The AC4825 is an outstanding machine, and when you consider the low price… it’s incredible. It’s truly one of our favorites and top recommended units. Just try finding another unit at this price with true HEPA filter, with activated carbon, and a ton of outstanding reviews. We’ve tried.

It’s great for those of us who live in communities with low overall air quality. But, not for those with large rooms as this purifier is only rated for 155 square feet.

However, if you are seeking a machine specifically for smoke or a lot of VOCs you may want to look elsewhere, such as this purifier. This machine does feature an activated carbon filter but it does not contain enough carbon to be incredibly effective against large amounts of smoke and other intrusive odors. But, it will help.


indoor dust sources

GermGuardian AC4825 Air Purifier Summary

Overall, the GermGuardian is one of the best value air purifiers on the market. It is rare to find a machine that offers the same level of quality at such a low price. Consumers love it, and levy very few complaints.

GermGuardian AC4825 Air Purifier Review


  • Washable pre-filter with activated carbon
  • True HEPA filter
  • UV-C technology kills bacteria
  • Energy Star certified


  • Small machine not suited for large rooms

What we learned preparing this Germguardian ac4825 Review…

The GermGuardian was one of our favorite machines when we first started learning about purifiers. Especially for people sticking to a budget. Its low price made it accessible to nearly anyone, and the quality seemed pretty solid. Users rave about its performance and love that it can eliminate dust, cooking odors, and reduce allergies and asthma symptoms. However, as we logged more time on other machines we changed our views a bit.

How did they change? Well, we started seeing more value in purifiers that are slightly higher priced. Most notably the Honeywell 50250-s. Granted that machine costs almost twice as much as the GermGuardian, but the Honeywell is probably 3 to 4 times the machine. It actually compares nicely to Austin Air purifiers which start in the high $300 price range.

We’re definitely not saying that the GermGuardian is bad… just that you’ll get more out of each dollar spent by considering other options. If you prefer a more high-end air purifier, or a machine more effective at eliminating strong odors, there are a variety of options that will surely to meet your needs. But, this purifier is awesome and affordable so it’s definitely worth a try even if you get something from Alen, Blue Air, or Rabbit Air.



Summary: The AC4825 is one of our favorite purifiers. It has similar features to high end units at a fraction of the price.


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    The AC4825 air purifier is GermGuardian’s best-selling machine. It’s also one of our favorites. The GermGuardian AC4825 is among the most efficient ...
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