Sylvane GermGuardian AC4825


Price $99.99
CADR (Clean Air Delivery Rate) rating 100-125
HEPA filter? Yes
Energy Star certified? Yes
Area coverage 155 square feet
Dimensions 7 x 10.2 x 21.5 inches

The GermGuardian AC4825 is inexpensive, exceptionally quiet and provides strong value at its price point – which for many people, will be enough. The device tackles all kinds of odors with great efficiency, and effectively neutralizes dust, mold and allergens in small spaces.

But this unit works slowly and is less effective in medium-large rooms. Additionally, there are some questions about the durability of the product – both in terms of filters and the device itself. It should be noted, however, that a little bit of maintenance goes a long way to correcting the latter issue.

A fine entry-level purifier for people on a budget.

Read the full review below.

  • Great price
  • Extremely quiet
  • Thin and unobtrusive

  • Works slowly
  • Not powerful; designed for small rooms
  • Some questions about durability


The GermGuardian AC4825, at one point in 2015, was the best-selling HEPA air purifier on Amazon. But popularity doesn’t always translate to effectiveness. Let’s dive into the ins-and-outs of this device.

The first thing that jumps out is the price. At $99.99, this is about as cheap as they come, as far as decent air purifiers go. I won’t lie; the low price tag made me skeptical about how well this unit would work.


But price be darned, the GermGuardian AC4825 is actually an impressive little unit!


Let’s tackle performance first. This unit is on the smaller side, so it’s not a surprise that it works pretty slowly and isn’t a behemoth when it comes to power or efficiency (CADR rating of 100-125). But it works pretty well, and that’s the bigger takeaway. The AC4825 handles smells and odors with great efficiency – smoke, kitchen smells, you name it.

Allergens, molds and dust are also toast with this device in small rooms. I’m extremely impressed with how well the unit works given its size and price. I’ll say it again: it works slowly, and it’s made primarily for your smallest rooms, but it does what it’s supposed to.

Size and Sound

This device has two big selling points, aside from price and performance: it’s very quiet, and it’s small and sleek.

Its official dimensions are listed at 7 x 10.2 x 21.5 inches; in other words, you can stick it in a corner and let it work, and you probably won’t notice it’s there.

The quiet factor plays into that, too. This device is wonderfully quiet – it’s great for using in rooms you’ll be sleeping in. The device will get louder as time goes on; but 80 percent of that excess noise can be mitigated by cleaning the filters every so often. I’d recommend water-cleaning or vacuuming the filter once every week or two to maintain peak performance.

The design is pretty chic, as well. The unit is covered by a sleek black plastic that makes it look like a more expensive purifier than it really is. The top of the unit is covered in a soft UV light.

Speaking of UV lights: one question I commonly get regarding this device is whether it emits ozone. The answer is NO, it does NOT emit any ozone – although that’s an issue you need to watch out for with any UV purifier.

The Bad

OK, let’s talk negatives.

Many, many buyers have expressed concerns about a strange, plastic-type smell that the AC4825 seems to emit when it first comes out of the box. The small lingers for as little as 18 hours or as much as 3 weeks. That’s not good.


But unless the device is defective, that chemical smell will go away within days in 95 percent of cases.

Another issue: with a price under $100, this device gives the illusion of a great value. Don’t get the wrong impression: the value is good, but it’s not great. For proof, look no further than this devices CADR rating, which sits between 100-125. In terms of “$ vs. CADR”, this device actually lands on the expensive side of things.

Furthermore, the unit can handle an area up to 155 square feet – but it takes a long time to churn through that air and cleanse the room. Although, like I mentioned earlier, the device gets the job done. It’s just takes its time.

It’s funny: I just finished reviewing the Honeywell 50250-S, and these units are complete opposites. The Honeywell is a chunky, eye-sore device that works very fast and effectively but sounds like a construction site.

The GermGuardian AC4825 is small, slow and quiet. But in both cases, the purifiers get the job done.


7 Total Score

The GermGuardian AC4825 is inexpensive, exceptionally quiet and very well-made. But it works slowly and its not very powerful, which holds the device back from achieving outstanding value. All in all, an excellent entry-level air purifier for small rooms.

Noise Level
Other Factors (Durability, Energy Efficiency, Design)

1 Comment
  1. Reply
    Honeywell HPA 300 May 31, 2015 at 2:10 pm

    […] Before I end the review, I wanted to touch quickly on noise level. The HPA 300 is actually really quiet on low and medium settings. On all settings, it is quieter than the Honeywell 50250-S but not as quiet as, say, the GermGuardian AC4825. […]

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