GermGuardian AC4825 Review- Buy or not?

GermGuardian AC4825


The GermGuardian AC4825 is tall (9 x 5.5 x 22 inches) but small and light (only 8.55lb). It also has a handle on the back so it’s easy to move around.

The GermGuardian AC4825 air purifier is a tall, black unit that has silver accents on the top. The controls are located on the top of the unit. The air intake is located at the front of the purifier, and clean air is distributed through the back.

The Germ Guardian air purifier is a filter that is medium-sized and tall. It is designed to be placed on the floor of any room. It is powerful enough to treat small to medium-sized rooms.


GermGuardian AC4825

There is a green light on top of the air purifier that comes on when you turn it on. You will also see a thin blue light around the top of the unit when you turn on the UV function. However, the UV implementation on this unit is not very good, so you probably won’t want to use it. Nevertheless, the green-ray on the top of the unit will always be on, so if you plan on using the unit in a dark room and you’re sensitive to lights illuminating the room at the same time, be aware of this.

The Winix 5500-2 and Coway air purifiers are two of the best on the market. They both have lights that cannot be turned off. If you are looking for an air purifier in the price range that has control panel lights that can be turned off, both the Honeywell HPA series and most Levoit units offer this functionality.

The AC4825 is much smaller than it looks in photos online. The unit looks like a standard tower fan in the photos, but it is actually much smaller. The unit is about 22 inches tall but it is only 7 inches wide and 10 inches deep. A full-size air purifier like the Winix 5500-2 is taller, wider, and deeper. Both the AC4825 and the Winix 5500-2 are light. The AC4825 weighs just over 8 lb., while the Winix 5500-2 weighs 16.5 lb.

This GermGuardian air purifier has a very simple design that lacks extra features you might find on more costly models. The unit lets you set it to 3 other fan speeds and turn UV functionality on or off. That’s all.

The Winix 5500-2 and Coway Mighty are more expensive options. They both have a timer, a particle concentration sensor, and an auto mode. The Winix also comes with a remote and one extra fan speed.




  • Color: Black
  • Product Dimensions: 10.25 x 6.75 x 21.5 inches
  • Item Weight: 8.55 Pounds
  • Control Method:
  • Wattage: 55

Particle Filter

The AC4825 has a HEPA filter to remove particles like pollen, dust, mold spores, and more. HEPA filters are the best way to remove these types of particles. They are very efficient and can remove 99.97% of them on the first try.

The AC4825 comes with a HEPA filter, which is impressive for its price. Many other units in the same price range come with a HEPA Type filter (an imitation of HEPA filters) or a proprietary particle filter (a brand-specific particle filter that doesn’t have HEPA level efficiency). The Blue Pure 411 is an air purifier that is very effective. It has a proprietary particle filter with 99% efficiency (compared to 99.97% for HEPA filters).

All of the air purifiers that are more expensive than the AC4825 have a particle filter called HEPA. This type of filter is also found in the Coway Mighty and Winix 5500-2 and the Coway AirMega. Even some of the more expensive Rabbit Air air purifiers come with a HEPA filter.

The HEPA filters in these bigger more costly units have a similar structure with the same efficiency rating as the HEPA filter inside the AC4825. The only difference between them is size. The AC4825 filter is much smaller.

Gas Filter

The AC4825 air purifier is similar to other air purifiers. It has an activated carbon filter to remove unwanted gases, like VOCs and odors. The carbon filter in the AC4825 is made up of a fibrous material that is coated with carbon. This type of carbon filter is found in many low to mid-priced air purifiers. The AC4300, Honeywell HPA100, Blue Pure 411, and Coway Mighty all have the same type of carbon filter.

Some mid-to-high-end air purifiers have carbon filters with actual carbon pellets. The Winix 5500-2 is an example of a mid-priced air purifier with this type of filter. Coway AirMega and Rabbit Air are higher-priced examples.

If you are looking for a gas filter, it is best to buy one that has a carbon pellet filter. This type of filter is better than the kind that has fibrous material.

There are two types of carbon filters – the first type has actual carbon pellets, and this is the better option for gas filtration. If gas filtration is a priority for you, be sure to buy an air purifier that has this type of carbon filter installed (like the Winix 5500-2).

Another important point to make about the AC4825’s carbon filter is that it is not as good as other air purifiers’ filters with fibrous carbon. The AC4825 has less dense fibers than the other carbon filters we tested. The fibers are also loosely held together, which means they can break off when you remove the filter. This was a problem with all of the GermGuardian air purifiers we tested.

The AC4825 is not a good choice if you want a unit that filters out gas. It does not work as well as other units with a fibrous carbon filter or units with a pellet-based carbon filter.


The carbon filter in the AC4825 also acts as a pre-filter. This means that it not only removes unwanted gases but also larger particles. This helps to prevent the HEPA filter from becoming clogged quickly.

This setup is common in lower-priced air purifiers. The Honeywell HPA100, GermGuardian AC4300, and many other units in the same price range have this set up – a carbon filter that also acts as a pre-filter.

Some more expensive units have a separate washable pre-filter. The Coway Mighty and Winix 5500-2 both have this type of pre-filter. This means that the pre-filter can be washed instead of needing to be replaced (the carbon filter on the AC4825 has to be replaced).


The AC4825 air purifier has a UV light bulb that is very weak. It is only 5 watts. The UV light is also in a shielded compartment on the top of the machine. The UV light is on the AC5250PT air purifier. It is down the whole intake side of the purifier. The light goes on all the air that goes in. The UV light is in a separate compartment on the AC4825. We think it is not a good idea to have any light in that compartment because it does not reach the intake air well.

The useful info is that you don’t need UV light to kill germs. The germs get filtered out of the air by the unit’s HEPA filter, whether they are dead or alive. The unit’s lack of a correctly executed UV light does not matter. Actually, if it did have a properly executed UV light, it is not necessary to filter germs.

Air performance

The AC4825 was able to reduce the number of particles in a 150 sq. ft. room from 10,000 to 1,000 in 23 minutes. The higher concentration of particles (10,000) is considered “dirty” air while the lower concentration (1,000) is considered clean air.

This time is about what we expected. This is because the AC4825 has a HEPA particle filter and an output of about 140 CFM. For comparison, the GermGuardian AC4300 also has a HEPA filter and the same approximate output (CFM), so it took about 26 minutes. The Honeywell HPA100, also equipped with a HEPA filter and the exact approximate result, took 22 minutes.

The top-rated 250 CFM HEPA-equipped Coway Mighty and Winix 5500-2 each took 9 and 10 minutes, respectively.

We let the air purifier run for several hours to see how low of a particle concentration it could achieve. The AC4825 was able to achieve a concentration of 500 particles per cubic ft. It took an additional 40 minutes on top of the initial 23 minutes to reach this concentration starting at 10,000 particles per cubic ft. Past this additional 40 minutes particle concentration would continue to oscillate between 500 and 1,000 particles per cubic ft. The absolute lowest concentration this unit was able to achieve was 500 particles per cubic ft.

The lowest concentration of particles the GermGuardian AC4300 and Honeywell HPA100 were able to achieve was 900 particles per cubic ft. The higher CFM units like the Coway Mighty and Winix 5500-2 were able to achieve a lower concentration of 100 particles per cubic ft.

This machine lowers the level of particles in the room quickly. It is as fast as other machines with a similar particle filter (HEPA). Machines with a higher CFM (Cubic Feet per Minute) lower the level of particles more quickly and to a lower level.


The AC4825 did well in our noise output tests. It was measured at 61.2, 54.8, and 44.2 dB on high, medium, and low fan speeds. For comparison, most other lower CFM air purifiers we tested got similar results. The AC4300 was a bit quieter – measured at 58.6 dB on high. The Blue Pure 411 was a bit louder – measured at 65.4 dB on high. But you cannot tell the difference between these units without the help of a sound meter.

Higher CFM units are louder at their highest fan speed, but they also have more than twice the output. The Coway Mighty was measured at 66.1 dB and the Winix 5500-2 was measured at 67.5 dB on their highest fan speed when they were both producing around 250 CFM of output.

On lower fan speeds, high CFM units work really well. For example, the Winix and Coway were both measured at only 48.9 dB on their second-highest fan speed. In this setting, they both still output around 100 to 120 CFM. This indicates that you can operate these units on their second-highest fan speed in smaller spaces (up to 150 sq. ft.) quietly to lower and keep low particle concentration and in larger rooms (up to 300 sq. ft.) to maintain low particle concentration (after running them on their highest fan speed to lower it).

Overall, the AC4825 is about as quiet as other similar-priced models and can produce a similar amount of airflow. However, it doesn’t compare as well to higher CFM units in terms of noise levels. If you’re looking for a unit that can lower particle concentrations in a 150 sq. ft. room, a higher CFM unit like the Coway Mighty running on low fan speeds is much quieter than the AC4825 running on maximum fan speed.


The AC4825 is a good value at around $80. Its build quality is not as good as more expensive options, but it is still good overall.

The unit has a 3-year warranty. More expensive options often have longer warranties, but that is not always the case. The Coway Mighty has a 3-year warranty, and the Winix 5500-2 only has a 1-year warranty.

This is not the most durable air purifier we tested. But it is very cheap and its build quality is more than sufficient. If it breaks, you can replace it easily and cheaply, even if it is not under warranty.

Energy efficiency

The AC4825 showed average energy efficiency compared to other units in the same size class. Its power draw was measured at 44.2, 38.2, and 34.2 watts on high, medium, and low fan speeds. Turning on the UV light added about 4 watts.

For comparison, most other 100 to 150 CFM units we tested had a power draw between about 20 and 50 watts, depending on fan speed. This gives these units a CFM/watt ratio of 2 to 3, depending on the exact model and exact fan speed.

Higher CFM units were more additional power efficient. This means they used less power to create the same or more airflow. The Coway Mighty, for example, uses less than 10 watts on medium and low fan speeds. On medium, it still outputs 100 CFM of air. This gives it a CFM/watt ratio of 13 on medium. On high it draws 72.3 watts of power but outputs 250 CFM of air for a ratio of 3.4.

If you are looking for an energy-efficient air purifier, then a higher CFM unit like the Coway Mighty is a better option than a lower CFM unit like the AC4825.

Price & Value

The GermGuardian AC4825 is a cheap air purifier, retailing for around $80. But that doesn’t mean it’s a good value. Value is about the price you pay and what you get for that price. The AC4825 is a good value for its price. It is not the best value on the market, but it is good compared to other options.

The AC4825 has some major problems:

it doesn’t have a good gas filter

it doesn’t have a separate pre-filter that you can wash

It offers very average performance in all categories.

should I buy it or not? Yes, but you need to be aware of what you’re getting. This unit is good for smaller rooms (up to 150 sq. ft.) where particle filtration is the only requirement. But it doesn’t work as well as more expensive full-size options.

The Winix 5500-2 is a good choice for a full-size air purifier for $150. It offers better gas filtration, particle filtration, and energy efficiency than other models. It also operates more quietly.

What type of air filter do you need? This depends on your requirements and budget. If you only need a filter for a small room, then the AC4825 is a good option that costs about $80. If you want a better air filter that does a better job of filtering the air and offers more features, then the Winix or Coway Mighty are good options that cost between $150 and $200.

User Experience 

I have asthma, and I noticed that my symptoms got worse when I spent time in my room. I used my inhaler more often than usual, and I couldn’t understand why. Then I realized that the problem might be my room’s air. I had seen ads for air purifiers before, but I didn’t think they worked.

I didn’t know much about HEPA filters until I started nursing school. I learned that they can be really helpful for hospitals because they can help with my symptoms. After doing some research, I found a good air purifier on Amazon called the germ guardian purifier. It had great reviews and I could tell that the people who left feedback were real customers. So I decided to try it out. I’ve had this air purifier for about 5 months, which has helped me a lot. If they were a little less expensive, I would buy one for every room in my house, but for now, I’ll just have to settle for one.

Pros & Cons

  • This air purifier is AHAM Verified and Energy Star Certified.
  • It has a True HEPA Filter to kill germs and UV-C light.
  • It also has a 3-year warranty.
  • The filter and UV-C replacement indicators let you know when it’s time to replace them.
  • This purifier is great for asthma and allergies.
  • It’s worth the money.
  • A carbon filter can help to get rid of bad smells, like smoke, food, and so on.
  • The original filters are too expensive.
  • The UV-C light is not in a good position.
  • There is no sleep mode.
  • The charcoal filter could be better.
  • This device cannot detect air quality in real-time and must be used in manual mode.


I think that the Germ Guardian is a good value. It has a basic design with limited features, but it is easy to use and would be appropriate for most small to medium-sized areas. The price is not too high, so if you are looking for a reasonable price and basic controls, this product would be a good option.

The GermGuardian AC4825 is a good air purifier for small spaces. has good purification performance, and decent area coverage. If you are looking for a basic air purifier that can be placed in a corner. It was able to reduce the amount of PM2.5 by 0.5 and AQI by 0 in our tests. The controls and usability are simple, using a single dial control.

There are no sensors or extra accessories. If you are looking for an air purifier that is easy to use and doesn’t have any extra features, then the GermGuardian might be a good pick for you.

Photo of author

The author is an Air purifier expert with overall knowledge of air and ionizers.