GermGuardian AC4100 Review In 2022: Cheap + UVC Sanitizer
GermGuardian AC4100 Specification
Product | GermGuardian AC4100 |
Dimension | 6.5 x 11 x 7.5 in (16.5 x 27.9 x 19.1 cm) |
Weight | 4.85 lb (2.2 kg) |
Fanspeed | 3 |
Coverage (up to) | 78 sq. ft. (7 m2) |
Airflow speed | |
Dust free (CADR) | 56 cfm (95 m3/h) |
Pollen free (CADR) | 76 cfm (129 m3/h) |
Smoke free (CADR) | 50 cfm (85 m3/h) |
Humidifying(H) speed | |
Filtration | 4-stage |
Pre-Filter - Lifespan - Replacement cost ($) | Charcoal Pre-filter 6 - 9 months |
HEPA filter - Lifespan - Replacement cost ($) | HEPA filter 6 - 9 months |
Carbon filter - Lifespan - Replacement cost ($) | - |
Ionizer/ Technologies | |
UV-light/ PCO | LB4100 UV-C Light 10 - 12 months14.99 PCO Filter |
Other filter | - |
All-in-one filter - Lifespan - Replacement cost ($) | FLT4100 Filter-E HEPA 6 - 9 months 24.99 |
Optional/ Addon | - |
Noise level | |
Power usage level | |
Timer/ Scheduler | |
Sensors | |
Auto mode | |
Air qualityAQ indicator | |
Filter change indicator | |
More color options | |
Wi-Fi/ BTBluetooth | |
ENERGY STAR | |
Remote control | |
Child lock | |
Warranty | 1 year |
Email/ Phone support |
Key Features
- 4-stage filtration with 3 speed
- Charcoal pre-filter
- Combination HEPA Filter
- Optional UV-C Metal Shield with Ti02
Design And Usability
At a mere 6.5 x 11 x 7.5 in dimension, GermGuardian AC4100 is a very compact air purifier that looks identical to the size of a single speaker. You can place it on a desk, island table, nightstand, or top of the cabinet in either horizontal or vertical position. Adding to the flexibility is the 4.85 lb lightweight for easy carrying despite the lack of a carrying handle. At the rear, you will find the air inlet covering most of the air purifier, and the air outlet is the other way round. The rear inlet can be effortlessly removed for a quick filter change. Overall the build quality is “cheap”, but it will do its job in holding everything together.

On to usability, AC4100 is very simple to use as there is only one front dial knob for 3 fan speed control and UV light on/ off button. You have the Filter Reminder back wheel at the back that requires manual adjustment. What we actually miss the most is a timer that allows us to set the hours we need GermGuardian AC4100 to turn off. Moving on, there are 4 felt pads you can stick it depending on what position you want the air purifier to operate in (again, AC4100 works on both horizontal and vertical placements). Other than that, there is nothing much in it other than the 4-stage filtration and a standard 1-year warranty. A basic air purifier that will work exactly as advertised.
Airflow, Coverage, And CADR
There is a price for an entry-level compact air purifier, and the airflow output is always the first hit. GermGuardian AC4100 estimated 60-78 sq. ft. purifying coverage is poor even in its segment. It is solely meant for close-range use like desktop, bedside, or next to the litter tray. The 3-speed airflow delivery rate isn't any better either, although that is expected given the air purifier's limited performance. When given enough time, you can still use it effectively in small room sizes e.g. a bedroom. GermGuardian AC4100 will remove close to 95% of large particulates after an hour of runtime. However, competitor models like Levoit Core 300 can do a much better job at half of the time.
Brand | Purifying Coverage | Fan Speed |
---|---|---|
Okaysou AirMax8L | 320 sq. ft. | 3 |
hOmeLabs HME020248N Purely | 80 sq. ft. | 3 |
LEVOIT Core 300 | 219 sq. ft. | 3 |
Hamilton Beach 04384 TrueAir Compact Pet | 140 sq. ft. | 3 |
Elechomes EPI081 | 215 sq. ft. | 3 |
TREDY TD-1500 | 200 sq. ft. | 3 |
Levoit LV-H132 | 129 sq. ft. | 3 |
Recommended Read
Filters And Performance
As mentioned earlier, GermGuardian AC4100 is a 4-stage filtration (3-stage officially) at a very compressed body. You have the initial carbon pre-filter that handles large particles like dust, lint, hair, debris, and light smoke pollutants. With those pesky particles out of the way, the HEPA filter would uninterruptedly capture smaller micron-sized particles at 99% efficiency, including dust mite, mold, and pollen. For biological pollutants e.g. mold, bacteria, and viruses, the last stage UV-C light + PCO filter will eliminate them inside the filtration with no chance of escaping before releasing the purified air out. Overall, AC4100 will remove common airborne allergens found in a household, but it is weak against odors and microscopic particles. The usage of inferior carbon pre-filter and the HEPA-type filter are the results of the budget constraint.

Noise And Energy Usage
You will be surprised the biggest complaint about is not the filtration performance but noise. GermGuardian AC4100 suppose to have a very decent noise level given its low airflow delivery rate; we find it rather loud at second speed onwards that outputs a distinctive high-pitch sound. If you are not sensitive about noise, the white noise can easily be drowned out by other appliances like a mechanical keyboard, dishwasher, TV, or fan running in the background. You will quickly get used to the fan noise during work, even when placed on the work desk. Leave it at the lowest speed for those who need absolute serenity with zero noise e.g. during sleep.
On the flip side, GermGuardianAC 4100 power consumption is low across all speeds, even if the air purifier does not have any eco-ness technology or auto mode. It uses only 0.025 kWh of electricity, which translates to a lower end of $3 a month or about $12 a year, depending on the operational hours and states you are in. Our unit has been running for months 24x7, and we have not seen any significant spike in our electric bill.
Noise Type | Decibels |
---|---|
Breathing | 10 dB |
Rustling leaves | 20 dB |
Whispering/ Quiet library | 30 dB |
Light rainfall | 40-50 dB |
Conversation | 50-60 dB |
Vacuum cleaner/ Hair dryer/ Washing machine | 65-80 dB |
City traffic | 80-90 dB |
Pricing And Maintainence Cost
^ Replacement filters/ estimated cost
No doubt Amazon has the best deal for GermGuardian AC4100, including free shipping with Prime, bundled purchase, and 30 days return policy. Guardian Technologies website and other retailers like BestBuy, Overstock, Walmart, Target should also be on your consideration list if you manage to find a better deal and don't mind the hassle of account registration.

GermGuardian AC4100 VS The Challengers

Hamilton Beach 04384 TrueAir Compact Pet
Similar price range, but TrueAir utilizes a permanent HEPA-grade filter that will save you on annual replacement cost. Purifying zone also doubles, but you will have to settle for a weaker filtration depth without UV-light technology.
GermGuardian AC5250PT
A much better proposal in our book with more than double of its purifying coverage, faster airflow delivery rate, 3 years warranty, and bigger, better True HEPA filter. All that for a bit of top-up.
Levoit LV-H132
Again, spend a little extra to get a better air purifier with a True HEPA filter, activated carbon filter, faster airflow distribution, night light mode, and cover more ground. Filter replacement cost is surprisingly lower.
Levoit LV-H126
Yet another Levoit air purifier that offers True HEPA filter, single activated carbon filter, wide 161 square feet purifying applicable area, and an extended 2 years warranty. LV-H126 looks much cooler and trendier too.Final Thoughts On GermGuardian AC4100
Air purifier keeps getting cheaper and cheaper every day. GermGuardian AC4100 is exactly that with an affordable price, small body, and cater for small room size. With a strong 73% 4-5 stars rating in Amazon, most praises focus on its low price tag and effectiveness against dust allergens. The 17% that gave 1-2 stars bad review are mostly concern about 2 things. 1) The durability where the air purifier dies with a burning smell coming from the circuit board. 2) It's loud. The QC issue is not as common as the suggested percentage, given the thousand units sold. The high-pitch fan noise can be clearly heard for an air purifier that is supposed to place on the desktop when running at max speed. If you want something that is dirt cheap and does not mind the subdued performance and relatively short 1-year warranty, go for it.Pros
- Affordable 4-stage filtration air purifier with UV technology.
- Beautiful speaker-like body that is compact and practical.
- Works in vertical and horizontal position.
- Charcoal Pre-filter that can be detached from the HEPA filter for vacuuming.
- UV-C light technology that can be turned off when not needed.
Cons
- Below average purifying coverage and filtration strength. Uses a HEPA-type filter that comes with "only" 99% efficiency.
- Annual filter replacement cost is high and can cost more than a brand new air purifier in 2-3 years.
- No addon features like timer or Auto mode, even though it is understandable given its size and price tag.
- Uses a manual filter reminder date wheel that feels weird in today's standard.