GermGuardian AC4825 Review

The 3-stage operating of this air purifier allow it to remove every impurity in the air, including bad odors, germs, mites, and allergens. Therefore, the benefits on your health will be countless and if you add to that the stunning design and the ease of use, you have an air purifier that can outcome many other models.

GermGuardian AC4825 Ratings

DESIGN - 92%



The 3-stage operating of this air purifier allow it to remove every impurity in the air, including bad odors, germs, mites, and allergens. Therefore, the benefits on your health will be countless and if you add to that the stunning design and the ease of use, you have an air purifier that can outcome many other models.

User Rating: 4.18 ( 21 votes)

If you’re new to the idea of purchasing an air purifier for your home, it might be overwhelming to choose among the many models available on the market today. With recent advancements in technology, many air purifiers have kept in step by utilizing different types of air-cleaning tech to combat different types of household air pollutants.

However, one brand has consistently proven that they’re able to provide reliable, high quality air purifiers at a low cost: GermGuardian. If you’ve done any research on air purifiers at all, then you’ve no doubt heard about this brand. In this article, we’ll be reviewing one of GermGuardian’s most popular models, the AC4825. Read our detailed review below!


  • Affordable (upfront)
  • Energy efficient
  • Sleek, space-saving tower-type design
  • Filter replacement indicator
  • Easy to use and maintain
  • Capable of removing different types of pollutants such as allergens, odors, and bacteria
  • Permanent pre-filter and charcoal filter


  • Small coverage area
  • Expensive replacement HEPA filter
  • No smart features or modes
  • Users report burning smell coming from the unit

Product Overview

The GermGuardian AC4825 is one of the most popular air purifier models to date, years after its initial release. There are several reasons for this, with the primary reasons being its affordability and reliability. Retailing at less than $100, you get a UV air purifier that can tackle all sorts of pollutants and cover small spaces up to 167 sq. ft. in size.

Admittedly, this unit is far from perfect despite its popularity. Because it’s so affordable, you can’t expect this model to have too many features or modes. Despite its affordable upfront price, however, its replacement HEPA filters do come quite expensive with yearly costs amounting to an entirely new unit!

However, one of the most important things to take into consideration with this unit is the alarming number of user reports saying that it emits a strong burning smell. While possibly an isolated issue, it’s definitely something to keep in mind especially if you live with children or pets.

Overall, despite these flaws, the AC4825 is still a solid air purifier for its price. It’s fully equipped to handle an array of different air pollutants with its HEPA filter, charcoal filter, and UV-C light technology. While a lack of smart features may be a downside, it makes the AC4825 a straightforward, easy-to-use device. Maintenance is also a breeze with its filter change indicator and easy-to-clean permanent filters.

Specifications Sheet

Specs GermGuardian AC4825
Dimensions 7 x 10.2 x 21.5 inches
Weight 7 lbs
Area Coverage 167 sq. ft.
Smoke CADR 108
Pollen CADR > 125
Dust CADR > 118
Fan Speeds 3
Filter Type Permanent Pre-filter, True HEPA filter
Odor Reducing Filter Permanent Charcoal filter
UV Light Technology Yes
Controls Knob and Button Control
Timer Function Yes
Warranty 3 Years

Features and Benefits

  • UV-C Light and Titanium Dioxide Technology – GermGuardian is known for incorporating the benefits of UV-C light treatment into their air purifiers. With the AC4825, it uses UV-C Light combined with the cleaning power of titanium dioxide. The UV light catalyzes the titanium dioxide to release electrons which break down potentially harmful air pollutants into harmless substances such as carbon dioxide and water.
  • Permanent Pre-filter and Charcoal Filter – The AC4825 uses two permanent filters: the pre-filter and the charcoal filter. This means these two filters will never need to be replaced, helping you save in the long-term. They only need to be vacuumed once a month to ensure continued efficient performance.
  • Filter Replacement Indicator – For the True HEPA filter, which is the only filter that needs to be replaced, the AC4825 comes with a filter replacement indicator that lights up when the filter has reached the end of its service life.
  • Ideal for Allergy and Asthma Sufferers – In a space of 167 sq. ft., the AC4825 is capable of completely cycling the air up to 4 times in an hour (4 ACH). This makes it a good choice for those who suffer from allergies and asthma because the minimum requirement for an air purifier to be considered effective against allergens is its ability to do 4 ACH, with the ideal being 5 ACH.
  • Energy Star Certified and CARB Compliant – You don’t have to worry about racking up your electricity bill with this unit because it is Energy Star Certified, the standard for energy efficiency. The AC4825 is also CARB compliant to ensure compliance with air pollution rules and regulations.


The AC4825 is equipped with 3 filters: a pre-filter, a True HEPA filter, and a charcoal filter. It also uses UV-C light technology in combination with titanium dioxide. With these in place, the AC4825 is fully capable of removing and eliminating everything from allergens to bacteria and viruses to odors. Furthermore, the AC4825 is AHAM-certified to combat pollen, smoke, and dust.

The biggest limiting factor to this device is definitely its room coverage. Rated to cover only 167 sq. ft., you can only use it in small rooms and anything larger than that will greatly lower its efficiency. In addition to this, several users have reported a strong, burning smell coming from their AC4825. Some have resorted to opening up the device to reveal charred circuitry. While the legitimacy of these incidences remains to be seen, the sheer number of complaints reporting this is definitely something to ponder.

Overall, however, the AC4825 remains a popular choice for people looking for an affordable, easy-to-use, entry-level air purifier. It may not have as many bells and whistles as other air purifiers in the market, but it definitely holds its end of the bargain when it comes to ridding your home of harmful air pollutants.


The GermGuardian aesthetic is quite easy to pick out because several of its models share more or less the same design. Standing at 22 inches tall, the AC4825 comes in a sleek, space-saving, tower-type design that allows you to place it anywhere in your home without having to worry about it taking too much space.

The control panel includes a knob to control fan speed, the filter change indicator light, and the UV-light button. This is admittedly not the most high-tech control panel design, but for a device this cheap, you can’t really complain.

Warranty and Support

Users of the AC4825 3-in-1 will get to enjoy a limited three-year warranty upon purchase. Per the agreement with the manufacturer, all repairs and replacements within the time period will be free of charge, provided that no tampering or unauthorized replacements have been implemented on the machine.

The use of any non-genuine parts unaccredited by Guardian Technologies will result in the nullification of the warranty altogether.

Final Thoughts

The GermGuardian AC4825 is popular for a number of reasons: it’s affordable, it’s easy to use, it looks good, and it scrubs the air clean — which is all that you would expect from an air purifier. However, it also has a number of limitations such as small room coverage, expensive replacement filters, and a lack of features.

When you take into consideration all these factors, the AC4825 still stands a solid choice for an entry-level air purifier. It uses different air purification technologies to help you eliminate household air pollutants and create a healthier, safer home for your entire family.

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  • Ted

    Is this unit silent enough to keep it in the bedroom at night? Or will it wake me up with a buzzing sound?

  • Hank

    I see that this model can handle removing unpleasant odors from the air. Does it mean that it will eliminate the nasty smoke smell as well?

    • The activated carbon filter that it features is capable of effectively removing smoke particles and odors from the air. Therefore, it’s a great solution for you to go with in case there are smokers in your household.

  • Valerie

    Are there any ozone emissions involved in operating this air purifier? I want to get it for the nursery and I want to be sure it won’t cause more harm than good.

  • Megan

    I like the UV light feature, it sounds great for sanitizing the house for the children.

  • Abby

    Will it keep the air in my child’s room clean enough? He is only 8 years old and he suffers from allergies, so I’m concerned that the air in his room might not be so great for him.

    • The UV-C light that this model comes with sanitizes germs by permanently destroying their DNA, while the unit’s overall performance ensures that allergens, dust mites, bacteria, and any other pollutants won’t linger in the air either. This makes it perfect for a child who suffers from allergies, this being the reason why we strongly recommend it for you.

  • Rufus

    I was aware of the fact that GermGuardian is one of the best brands on this market, so my interest in this model was even higher due to this reason. I’m definitely going to buy one for myself as soon as possible as I am confident that what’s in the review is actually true. My mom actually owns a GermGuardian air purifier, and she’s happy with it and wouldn’t change it for the world.

  • Benny

    For how long is it backed by a warranty?

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