GermGuardian AC4200W: Small Size, Average Performance

Full Review

If you’re looking for an air purifier, you’ve likely come across the GermGuardian brand.

This manufacturer is known as one of the best-selling on the market, offering a variety of models. However, one thing I don’t like about their devices is the outdated design, especially in some earlier models.

In this review, I will describe and analyze the test results for the GermGuardian AC4200W air purifier. It’s a small, more modern device compared to its predecessors, but it has slightly fewer features than, for example, the popular AC4825E model.

What also sets it apart from other GermGuardian air purifiers I’ve tested is that it doesn’t include UV-C light, relying instead on a three-layer filtration system.

All in all, this is an interesting air purifier from a very popular brand, and I believe it’s worth testing.

How We Tested the GermGuardian AC4200W?

1. For the filter efficiency testing, we used the Temtop LKC-1000S laser particle meter, which measures PM2.5 (µg/m3), PM10 (µg/m3), Particles (per/L), and HCHO (mg/m3) in the air, and also calculates the AQI.

2. We placed the GermGuardian AC4200W in two separate performance tests, one in a 120 sq. ft. (11 m²) room and the other in a 194 sq. ft. (18 m²) room. Then, we recorded the initial air quality values using the Temtop laser particle meter and let the GermGuardian AC4200W run at maximum speed.

3. After 60 minutes, we measured the new values using the Temtop laser particle meter and saved the data.

4. Next, we placed the GermGuardian AC4200W in a glass box, which we then filled with smoke. Then, we measured how much time was needed for the air purifier to remove all the smoke from the box.

5. Using a special noise measurement tool, we tested the air purifier’s noise level at all speeds. We measured the noise level on the dBA scale.

6. Finally, we measured the power usage at all speeds using an energy meter, after which we calculated how much it would cost to use the device at a particular fan speed for one month. For reference, we used an energy price of $0.12 per kWh.

The GermGuardian AC4200W is an air purifier designed for rooms up to 105 sq. ft. (10 m²), making it a great fit for small kids’ rooms, small bedrooms, or other similarly sized spaces.

We tested it in two different room sizes, and the first thing I want to point out is that its performance pleasantly surprised me.

Although the GermGuardian AC4200W isn’t a device I would recommend for odor and bad smell neutralization; it’s excellent for particle removal.

Testing in a 120 sq. ft. (11 m²) Room

In the first test, we placed the GermGuardian AC4200W in a room measuring 120 sq. ft. (11 m²), which is slightly larger than the recommended size.

We set it up in this room, measured the current air quality using a Temtop laser particle meter, and let it run at maximum speed for 60 minutes.

After that time, it reduced PM2.5 particulate matter from 91.5 to 7.9 µg/m³, an impressive air quality improvement of 92%.

This result puts the GermGuardian AC4200W in the same range as the Blueair Mini Max, which produced identical results in this test.

Of course, some air purifiers showed lower performance in this test. One of them is the Aroeve MK01, which improved air quality by 86%.

You can compare this performance with other similar air purifiers in the chart provided above.

Testing in a 194 sq. ft. (18 m²) Room

In the second test, we placed the GermGuardian AC4200W in a much larger room than the recommended size.

While running at maximum speed for 60 minutes, it managed to improve the air quality by 90% in a 194 sq. ft. (18 m²) room.

This is an outstanding result, especially considering the room is almost twice the recommended size.

The test in a room of this size proves that the AC4200W can effectively improve air quality even in larger spaces than recommended.

Performance – Smoke Removal Test

The GermGuardian AC4200W uses a very small filter and has a CADR of only 68 CFM (115 m³/h), so I didn’t expect it to perform anything revolutionary in the smoke test.

However, it managed to remove all the smoke from the box in just 43 seconds. While this isn’t an outstanding result compared to similar air purifiers, it’s still in the range of some much larger devices.

For example, the Hathaspace HSP001, which has a much larger CADR and filters than the GermGuardian AC4200W, only achieved a result that was 1 second faster in this test.

As I mentioned earlier, the GermGuardian AC4200W didn’t produce groundbreaking results in this test, but considering its specifications, I’m relatively satisfied with its performance.

When it comes to the noise level test, I must say I expected the AC4200W to be much quieter, especially at the lowest speed.

It produces a sound level of 49.3 dBA at its lowest speed, making it one of the loudest air purifiers at the lowest speed among all we’ve tested.

The only air purifier that I would say is similarly loud to the GermGuardian is the Honeywell HPA100, which produces a sound level of 48.2 dBA at its lowest speed.

The noise level at higher speeds is average and doesn’t deviate much from other similar air purifiers. At maximum speed, the AC4200W produces a sound level of 63.1 dBA, which is slightly loud for such a small device. However, the noise at maximum speed is better optimized than at the lowest speed.

I truly believe that GermGuardian could have put more effort into optimizing the motor’s noise level, at least at the lowest speed.

This small air purifier uses a motor with a power consumption of only 26W, making it one of the lower power consumers among all the air purifiers we’ve tested. It’s also Energy Star certified.

If you use the GermGuardian AC4200W at maximum speed, 24 hours a day, for a month, your electricity bill will increase by about $2.70.

Frankly, this is slightly higher than I expected, especially when compared to the power consumption cost of some similar air purifiers. For instance, the Shark HP102 would cost about $1.80, and the IKEA FÖRNUFTIG would cost around $1.16.

In addition to electricity costs, there’s also the cost of filter replacement, which typically lasts up to 6 months. I recommend maintaining and cleaning the filter regularly to prolong its life and ultimately reduce maintenance costs.

Overall, if we sum up all the costs, we can say that the GermGuardian AC4200W is relatively affordable to maintain on an annual basis.

Filtration Technology

The GermGuardian AC4200W uses a True HEPA filter in combination with an activated carbon filter. The filter is round in shape, and located at the bottom of the device.

The first thing that caught my eye about the filter is the filter dimension which is very small compared to the device. A similar situation is with the TruSens Z-1000 filter, which is also much smaller than the device. 

Honestly, I think that the manufacturers would have benefited much more if they had used a larger filter and that the device’s performance would have been much better in the long run.

Activated Carbon and Pre-filter Combination

The first stage of filtration is a combination of charcoal and pre-filter. Its purpose is to reduce unwanted odors from pets, smoke, cooking fumes, and other terrible smells.

This combination is not always the best solution, mainly because the pre-filter needs to be cleaned frequently. The filter material breaks easily, leaving you in a situation where the whole filter needs to be replaced.

Another complaint is that this fiber filter is carbon-coated, which can adsorb much less gas than a carbon pellet filter.

Overall, the AC4200W has not performed too badly on gas tests. It performs well in these situations. However, if this level of filtration could be improved, there would be better performance and greater efficiency.

True HEPA Filter

The last level of filtration is the True HEPA filter. It is commendable if a product in this price range uses a True HEPA filter, so I have nothing but praise for this level of filtration. A True HEPA filter captures 99.97% of microscopic allergens, dust, and mold spores down to 0.3 microns in size.

How to Replace the GermGuardian AC4200W Filter?

The filter reset indicator lets you know when it’s time to change the filter. The GermGuardian AC4200W has an average filter life of between 6 and 8 months. However, in my experience, due to the very small filter, I think it will get dirty much quicker, and you will need to replace it sooner. So I think that the filters on this machine will last a maximum of 6 months. In any case, the replacement time depends on the way the air purifier is maintained and the conditions in which it is used.

It is recommended to clean the pre-filter at least once a month as this prolongs the filter’s life and keeps the filtration at a constant high level. The carbon filter on this model is replaceable. Suppose you feel that the unit is losing performance in filtering gases. In that case, you can order as many as four carbon filters in the box and change them as needed.

Total time: 10 minutes.

Setup and Installation

The GermGuardian AC4200W does not require much complex preparation before the first start-up. However, I would like to point out that preparing the filter before switching on the air purifier is mandatory. This is done by opening the lid at the bottom of the unit, removing the filter, unpacking the same filter from its plastic packaging, and returning it back into the device. That should be all, and your GermGuardian AC4200W is ready for use.

I would also advise you to be careful where you place the device; I suggest moving the device at least 12 inches away from the wall or other objects.

Design

As I mentioned at the beginning of the review, GermGuardian has taken a step forward in design with the AC4200W. Until now, their air purifiers have been using old-school design, but recently they have released several models that follow all modern design guidelines.

The build quality is excellent, the plastics seem hard and solid, and everything is in place. Every part is in place, and everything seems very well-tightened.

The device does not have a carrying handle, but it is very light and small, so it will not be a problem.

The AC4200W is unevenly circular in shape; it is colored white except for the grey control panel on the top of the device. The white color, the modern design, and the overall impression allow you to integrate the GermGuardian AC4200W into almost any ambiance. And now you’ll be able to do that easier than with some older GermGuardian models.

Controls

The control panel is on the top of the device. The control panel has buttons and indicators. The buttons are touch-sensitive, very sensitive, and very easy to use.

You will find the ‘Power,’ ‘Speed,’ and ‘Timer’ buttons on the control panel. The fan speed button changes the motor speed with each press, the first speed is the sleep mode, and the last fourth speed is the turbo mode.

Airflow

Although the GermGuardian AC4200W has an unusual circular shape, the vents are not positioned over the entire surface. The vents are located on the lower half of the device but only partially on the front and rear sides. It also has vents at the bottom. The GermGuardian logo is painted on the front panel. As mentioned earlier, the AC4200W draws air through the vents, which is then filtered and exits through the grilles at the top of the device.

Size and Dimensions

The air purifier weighs 6.55 lb. The dimensions of the device are: 10.5 x 10.75 x 15.5 in. It is a very small device, so it can easily be placed on a bedside table, desk, or shelf.

What’s in the box?

When you buy the device, you get a GermGuardian AC4200W air purifier, instruction manual, and True HEPA filter.

The AC4200W requires preparation before the first start-up, so I advise you to look at the beginning of the review, where I describe the steps necessary to complete before starting the device for the first time.

Features Overview

The GermGuardian AC4200W does not have advanced features to highlight that are innovative and unique to this device. It is, however, slightly more creative and different from the GermGuardian AC4825, which of the advanced features only has a UV-C light.

To avoid prolonging the discussion, please see below for a description of this model’s individual options.

Timer

The timer is one of the options I have mentioned. Not very innovative, but very useful, especially if the device cannot connect to a smart app or if there is no auto mode. When you set the timer, the unit will switch off after a specified time. The AC4200W allows setting the timer to 2h, 4h, or 8h.

Filter Reset Indicator

This is a necessary option that makes no sense to omit on any air purifier.

The filter reset indicator essentially gives you “less hassle” it allows you to easily track and control the time when you need to change the filter. This means that the filter reset indicator on the control panel at the top of the unit will light up when it is time to change the filter.

Sleep Mode

The GermGuardian AC4200W has 4 speeds. The first speed is sleep mode. I really like the sleep mode on this model, but I honestly wish the motor volume is a bit quieter at this speed.

When you switch to sleep mode, the current speed indicator flashes for 5 seconds, and then all the indicators turn off. This means that you can easily use the GermGuardian AC4200W in a bedroom or other darkroom.

Ozone-free

As I mentioned earlier, the AC4200W does not use UV-C light like some of the other models in the GermGuardian series. It does not use an ionizer or any other level of filtration that could produce illegal amounts of ozone.

The GermGuardian AC4200W complies with California’s very stringent legislation. It is irrefutable proof that this model does not produce harmful amounts of ozone and is entirely safe to use.

Energy Star Certified

Energy Star is the simple choice for energy efficiency, making it easy for consumers and businesses to buy products that save them money and protect the environment. This certification verifies this model’s energy efficiency and low power consumption of just 26W. You can see the confirmation of the energy efficiency and very low power consumption in the “Operating Costs” section.

Motor Protection Circuit

The GermGuardian AC4200W motor is equipped with a protection circuit that is activated if the motor overheats and if it is used for a certain period without switching off.

When the protection is activated, the motor switches off, but the indicators continue to work. In this case, the device must be reset; this is done by disconnecting the device and leaving it to rest for at least 10 minutes. Then you just need to switch it on, and that’s it; you have successfully reset it.

Room Coverage and CADR

The GermGuardian AC4200W is designed for rooms up to 105 sq. ft. In a room of this size, the AC4200W cleans the air as much as 4 times when running at maximum speed.

It is most effective in rooms of very small dimensions, but even larger rooms are not a problem for it, as it performed very well in the tests I carried out in a room of 194 sq. ft.

I would like to point out that the GermGuardian AC4200W is AHAM tested, which means that the clean air intake rate data is accurate and verified. The CADR for this model can be checked in the table below.

CADR Score	Value (CFM)
Smoke	68
Dust	76
Pollen	77

FAQ on GermGuardian AC4200W