If you are searching for a table or desktop air purifier then you must lay your hands on this GermGuardian AC4100 model. Falling under the price category of less than 100 dollars, this air purifier is designed to meet its purpose well. Although there are no sensors or automation modes, it doesn’t fail to get the job done.

GermGuardian AC4100 Air Purifier Review

The GermGuardian AC4100 is specially manufactured for odor removal. This product has a charcoal layer that functions as a prefilter to confine larger dust particles. The activated carbon also captures various household and pet odors. It is best to be placed on a kitchen table to eliminate the smell after cooking. Additionally, it has a HEPA– and charcoal filtration system. Besides that it also comes with a UV-C light which is nothing but a titanium dioxide to manage airborne impurities such as germs and bacteria. Basically, titanium dioxide is a photo-catalyst which is found in paint and sunscreen and is the un-reactive solid substance that only reacts with sunlight, and is capable of killing bacteria when lit by ultraviolet light.

On the front end of the fan, the ON or OFF switch is present to control the UV-C light operation. This fan purifier has a two pin AC plug which you can connect into a 120V power outlet. There have been a few consumers who complained about a noise at the highest fan setting. However, it seems to be a normal fan sound which does not disturb people who are trying to sleep with the device on. Moreover, the spare bulbs are also available online here. Unfortunately, the AC4100 does not have an ionizer.

GermGuardian AC4100 Review Features

HEPA Filter: Filters up to 99% of the airborne impurities including dust mites, debris, spores, pollens etc.
Germs Shield: The UV-C light destroys germs and bacteria.
Odors removal: Eliminates unpleasant smell and smoke from the air; disposes of stink molecules caused by smoking, cooking, and pets
Kills Airborne Mold Spores: It destroys bacterial and fungal spores in the air
Compact Size: Ideal fit for small places
Dimensions: 7.5 x 6.5 x 11 inches
Cord Length: 6′
3-Speed Control
Filter Replacement Reminder
Replacement Filter E, Model FLT4100

GermGuardian AC4100 Air Purifier

Intro to the GermGuardian AC4100

The CADR value of this purifier is 64 for pollen. This means that it is manufactured to purify the air in small areas. The brand has not yet mentioned the approx measurement in square foot coverage but we assume it to be ideal for rooms measuring 70 to 80 square feet in size. The GermGuardian AC4100 is light weighted; being just 4.85 pounds in weight. The unit measures 7.5 to 6.5 to 11 inches which makes this air purifier ideal to put on a desk. Its compact design makes it portable as well.

This GermGuardian unit comes with two advanced and different filters; a HEPA filter and a charcoal pre-filter. On the context of maintenance, it is recommended to replace the HEPA filters once every 6 to 8 months based on the degree of harmful polutants in your surroundings. HEPA filters come in many grades but the replacement filter for this air purifier (FLT4100) is priced around 25 dollars, check the latest prices here. This filter is capable enough to destroy 99.97% of the airborne particles which are as tiny as 0.7 microns.

GermGuardian AC4100

3-stages of filtration

The GermGuardian AC4100 is praised for its high efficiency because it has a three-stage filtration system, which is a fantastic feature for this air purifier system as it destroys the airborne impurities like allergens, spores, and different household odors. The initial level of filtration works by passing the impure air through the activated charcoal pre-filter system, effectively trapping and destroying airborne bacteria.

It will also free the air from the nasty smell. The second stage of filtration process is where the air passes through the HEPA filter and this is where the 99.97% of toxic particulates in the air are captured. These impurities are dust, mold, bacterial spores, pet dander, pollen and other airborne contaminants that induce various allergies, infections, and even asthma. At the final stage, the air is treated by UV-C light which is a death ray for harmful microbes.

This is a pioneering technology which is made specially to destroy harmful microscopic organisms like viruses and bacteria. Not to forget, these microbes are the root cause of diseases like bronchitis, meningitis pneumonia, staph, and tuberculosis. The UV light also eliminates molecules that cause foul smell around the room which basically arise from cooking, pets, smoking and so on.


The Germ Guardian AC4100 is a compact air purifier system. This product sports a bass speaker-like design which indicates that it is suitable to be placed anywhere in your home or workplace. Measuring 7.5 x 6.5 x 11 inches, this air purifier is light in weight, which gives the consumers, an advantage of taking it anywhere without a hassle and it is also ideal to be carried while traveling. The wire cord measures around 6 feet in length.


GermGuardian AC4100 air purifier has a Clean Air Delivery Rate or CADR value of 64 which indicates its suitability for purifying and circulating air up to a 100 sq ft room. CADR is a number rating system that holds the maximum value of 450 which is assigned by the Association of Home Appliance Manufacturers (AHAM).


The GermGuardian AC4100 air purifier has a knob for its adjustment of three speeds in high, medium and low stages. For filtration stage, there is an on/off button to turn the UV-C lamp ON or OFF. Additionally, it also has a rotary indicator on the back end which is manually set by consumers to remind them when it is time to replace the filter.

GermGuardian AC4100 Review


The GermGuardian AC4100 air purifier needs a replacement pre-filter and HEPA filter which is sold together with the model name as FLT4100 Filter. These filters cost you around $20 and are to be replaced every 6-8 months. For keeping the warranty conditions intact you are advised to use genuine Guardian Technologies brand filters so that performance does not drip down. Apart from this, the UV-C light bulb that goes by the name of LB4100 also needs to replaced, if needed, and it will cost you maximum $15. As a word of caution, this lamp is mercury vapor based fluorescent lamp which is hazardous for immediate environment. Therefore, damaging the lamp or breaking it during replacement may cause harmful effects and infections. It is recommended to replace the bulb every year without damaging it.

Noise level and power consumption

GermGuardian AC4100 is equipped with the high-end motor that aids noiseless operation which is quite impressive and would definitely be loved by the customers. This attribute of the product makes it ideal for bedroom use since it does not disturbs at night. When compared to other regular household appliances, the decibel level of this purifier cum fan was found lower.

When it comes to the efficiency of this GermGuardian AC4100 air purifier, you will be amazed at its power output. It heavily cuts down your electricity bill due to its very low consumption even on regular use.


“CADR” is an acronym for “Clean Air Delivery Rate” which is a performance rating system assigned by the American Home Appliance Manufacturers Association (AHAM). A CADR rating scale is established to monitor the purifying capabilities of high-end air purifiers and several other appliances that destroy macro-particulates (mold spores, pollens etc) and the smaller particles and chemicals (viruses, aldehydes etc). Since AHAM charges for the brand marketing, most of the companies quote CADR stats which are not even listed at AHAM. When we see a CADR of 58 for smoke and 64 for Pollen for the GeGuardiam AC4100, remember that these are unlisted values.

GermGuardian AC4100 Videos

Conclusion: Should I Buy the GermGuardian AC4100

The compact GermGuardian AC4100 is mainly designed to purify the air in a single room. Guardian technologies have really done a great job in launching a product like this which ensures a customer’s good health. We can say that they have offered a solution for a local problem. So, if you suffer from any allergies, this purifier is good for you. It does not only filters the air but also destroys the harmful bacteria and other disease causing organisms by using UV technology. In case you are thinking about an apt solution for your entire home, we would suggest you buy another air purifier for each room. Or purchasing a larger air purifier with similar features.

Customer Reviews

I have bought the GermGuardian AC4100 during the end of the winter, to be ready for the pollen attack in the spring season. Normally, I keep my windows closed but on cooler nights, I leave them opened, especially in my bedroom. In summers, pollens are not a thing of vivid concern but indoor dust is since I use the A/C most of the time. But, I am satisfied and impressed with the way this GermGuardian AC4100 tackles all my problems without difficulty. I use it in my 120 square feet room.

I installed the GermGuardian AC4100 on my desk and after switching ON the UV-C lights with minimum fan speed, I depart from the room only to come back after a few hours. Surprisingly, the air smelled fresh, clean and lighter to breathe. Although, there is some faint plastic odor but it vanishes after some time. I was amused on the abilities of this tiny air purifier which is a savior for an allergy sufferer. I also get comfortable and relaxed sleep at night. Buying the GermGuardian AC4100 was a good decision.

GermGuardian AC4100 Picture

I replaced the old filter recently after knowing that I could extend the life of the filter by vacuuming it a bit every month. I figured out that I must retain a filter for at least six months for health safety reasons. Having a look at the nasty difference between the old and new filter, I feel lucky to have the GermGuardian AC4100 at home.

Another Review

Buying and using this product just for a day made me write this review because of its greatness. Living in an apartment, I keep our cat’s litter box in the second bedroom. After installing the fan there, it made the smell in that room unnoticeable as if it wasn’t there at all. Since we use lightweight litter, it is dustier than most of the run-of-the-mill litter and this makes the dust scattered in the whole room. I have not used the UV-C feature till now. Though I have owned this item for just a day now, I am highly impressed with the GermGuardian AC4100 instant result. I would definitely come back once I notice any difference in functioning.

Few customers stated that it operates with noise but if I were to say, using this fan in my bedroom at lowest setting also would not be loud enough to disturb me. I wonder how it is noisy for them but if this stands as a major issue, buy another purifier.

Update #1:

I have used the UV-C feature and found the least altercation in the current environment. I run this air purifier 24/7 and still it deserves to remain at my 5-stars rating.

Update #2:

I’ve removed the dust out of the filter two times since my last update and have allowed the fan to run continuously since my first review. It is fantastic till now.

Update #3:

I took out the HEPA filter a day before and noticed the dust and other impurities clogging it top down which is a good sign for its constant efficient working capability. Though, I ordered another filter as the recommended time for replacement is near for me but I don’t think it will be required after a thorough cleaning of this one. I just bought the new one so that it comes handy to me in emergency cases. No change in my rating yet.

GermGuardian AC4100 Picture

Update #4:

So I fibbed and came back before any explosion. I replaced the filter after several cleaning of the old one for about a year. From a few months, I have reduced the purifier usage as I don’t need it too often. One thing I noticed is that three different fan speed settings have filtered to yield the same high level gushing out of air whether it’s on LOW or MEDIUM or HIGH. I’ve witnessed this with my automobile fan too but in this scenario, I suppose that some resistors might have stopped working. The GermGuardian AC4100 is getting the same electrical current on all the settings. Also, my unit’s UV bulb has given up but that’s totally fine on the account of its prolonged usage by me. I strongly recommend this GermGuardian AC4100 and I am sure to buy another GermGuardian as soon as this unit gives up.

Update #5

No remarkable change. I don’t use it as often as I did previously as I kept the cat’s litter box into a closet to limit dust. The fan runs on the same speed at all the settings and I am planning to go for a higher-end model soon.

We hope you liked this GermGuardian AC4100 Air Purifier review. For our top 5 picks in air purifiers we recommend reading our “Top 5 air purifiers 2017” article.


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