Germ Guardian AC4100 4-in-1 Desktop HEPA Air Purifier

Germ Guardian AC4100 is a compact and simple air purifier, designed for small rooms, offices, and similar areas. Thanks to its stylish looks and smallish dimensions, it can easily fit on desktops, countertops, nightstands, and similar.

Germ Guardian AC4100 purifiers air using 4 different methods, thoroughly removing dust, lint, pet dander, bacteria, odors, VOCs, etc. Also, it is very simple to use and rather cheap and easy to maintain.

Published: October 29, 2020.

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Germ Guardian AC4100 Features and Specifications

Germ Guardian AC4100 is a very popular and affordable true HEPA air purifier, because of its simplicity and efficiency.

Germ Guardian AC4100 is able to filter out at least 99.97% of 0.3 microns or larger particles, including bacteria, dust, pet dander, VOCs, odors, pollen, and other potential allergens and harmful particles and gasses.

As its label says, Germ Guardian AC4100 features 4 layers of air filtration including:

- pre-filter and activated charcoal air filter: capture larger airborne particles and absorb odors and certain chemicals,

- true HEPA air filter: captures dust, pollen, pet dander, and other very fine particles,

- UV-C light: kills airborne viruses and germs that have managed to pass through the previous air filters,

- Titanium-Dioxide (TiO2) in combination with UV-C light reduces VOCs and certain other chemicals.

These four layers of air filtration ensure true HEPA air filtration, and odor and VOCs reduction.

Controls are very simple - air speed selector with three speeds including Low (ultra-quiet, also known as Sleep Mode), Medium, and High.

Also, there is an On/Off switch for UV-C light. Some people turn it off due to the fear of ozone production - ozone is actually produced, but in amounts that are below recommended/safe values. But, just in case, if the unit is kept at the nightstand during the night, perhaps it is not a bad idea to turn the UV-C light OFF and then to turn it ON during the day, when nobody is near the unit or not in the room.

Again, amounts of ozone are practically negligible, but just in case ...

Note: UV-C light is ON, when the switch is 'in' and turned OFF, when the switch is 'out' - there is no UV-C control light (which would be great). Also, if the fan is not running, the UV-C light is Off, even if its switch is 'in'.

Air flow inlet is at the back of the unit, and the exhaust is at the front of the unit.

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Also, the backside of the unit features a manual dial that represents the months of the year, which allows the user to mark the month when the air filter was replaced or when to replace it.

Germ Guardian AC4100 physical dimensions are (L x W x H) 7.5 x 6.5 x 11 inches (~19 x 16.5 x 28 cm) and it weighs 5.15 pounds (~2.33 kg).

The power cord is 6 feet (~1.8 long), allowing the user to position the unit where desired. Power consumption is very low - for example, UV-C light requires just 2 watts, and fan power consumption depends on the fan speed, condition of the air filters, and similar. The maximum power consumption for Germ Guardian AC4100 is 0.56 Amps (@120V AC).

Germ Guardian AC4100 is suitable for rooms and offices up to 78 square feet (~7.2 m2) and features AHAM verified CADR (Clean Air Delivery Rate) of:

- Dust: 56,

- Pollen: 76,

- Smoke: 50.

These CADR ratings aren't much, but the Germ Guardian AC4100 is a compact unit and it is not intended for larger areas. What is important is that it is a true HEPA air filter, easy and simple to use, with just a few simple, periodic maintenance tasks.

Note: when Germ Guardian AC4100 arrives, be sure to thoroughly read the manual - it is not a complicated unit, but it is highly recommended to get accustomed to your new unit quickly.

How to Maintain Germ Guardian AC4100 Air Purifier?

Maintenance procedures include:

- vacuum the air-filters with your regular vacuum and soft dusting brush every 3-4 weeks, depending on the usage and most common types of air pollutants. Also, vacuum the air purifier's interior. Note: Air filters are NOT washable.

- replace pre-filter with carbon layer and true HEPA air filter every 6-8 months. People with pets and/or asthma and allergies may need to replace the air filters more often.

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Note: Germ Guardian offers an air filter kit containing both pre-filter with charcoal layer and HEPA air filter, which is the recommended air filter replacement kit.

Again, for exact maintenance procedures, check the Owner's Guide.

Germ Guardian AC4100 comes with a 1-year limited warranty.


germ guardian ac4100 mLong Story Short: If You are looking for a desktop/countertop air purifier, consider Germ Guardian AC4100 - it is stylish looking and rather compact unit that it does its job well.

Also, it is a simple and easy to use air purifier and one of the most popular units in its class.

For more reviews and recommendations, feel free to check Germ Guardian AC4100 4-in-1 Desktop HEPA Air Purifier Amazon link (link opens in the new window).