GermGuardian AC4100 Review In 2022: Cheap + UVC Sanitizer

A speaker-like design air purifier with the latest UV Technology. Amongst GermGuardian AC4100's long list of features, the affordable price tag is arguably its main strength in this competitive small air purifier market. With a versatile body framework that is light and portable, is the air cleaner adaptive enough to take on other entry-level air purifiers? How are the filtration performances? What are the pros and cons? Hit the break to learn more.
online price (US)**
±89.99 $$/ 7

(annual filter cost ±48-65)

** MRSP (Manufacturer's Suggested Retail Price)/ RSP (Retail selling price) is accurate at the time of posting.
^ Annual filter cost is calculated based on filter price and 12 hours of usage. Pricing could vary depending on air quality, usage frequency, and speed.
` The indicated online price guides as follows: $ = under $50, $$ = $50-100, $$$ = $101-200, $$$$ = 201-300, $$$$$ = $301-400, $$$$$$ = 401-500, $$$$$$$ = over $500.

GermGuardian AC4100 Specification

ProductGermGuardian AC4100
6.5 x 11 x 7.5 in
(16.5 x 27.9 x 19.1 cm)
Weight4.85 lb (2.2 kg)
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
- 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
Optional/ Addon
Noise level
Power usage level
Timer/ Scheduler
Auto mode
Air qualityAQ indicator
Filter change indicator
More color options
Wi-Fi/ BTBluetooth
Remote control
Child lock
Warranty1 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

GermGuardian AC4100 dimension
6.5 x 11 x 7.5 in
(16.5 x 27.9 x 19.1 cm)
GermGuardian AC4100 weight
4.85 lb (2.2 kg)

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.

GermGuardian AC4100 controls

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

GermGuardian AC4100 coverage
Purifying coverage
78 sq. ft. (7 m2)
GermGuardian AC4100 fanspeed

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.

BrandPurifying CoverageFan Speed
Okaysou AirMax8L320 sq. ft.3
hOmeLabs HME020248N Purely80 sq. ft.3
LEVOIT Core 300219 sq. ft.3
Hamilton Beach 04384 TrueAir Compact Pet140 sq. ft.3
Elechomes EPI081215 sq. ft.3
TREDY TD-1500200 sq. ft.3
Levoit LV-H132129 sq. ft.3
GermGuardian AC4100 dust CADR
56 cfm (95 m3/h)
GermGuardian AC4100 pollen CADR
Pollen CADR
76 cfm (129 m3/h)
GermGuardian AC4100 smoke CADR
Smoke CADR
50 cfm (85 m3/h)
CADR follows the low rating pattern that is mediocre at best. You have dust CADR at 56 cfm, pollen CADR at 76 cfm, and smoke CADR at 50 cfm. Smoke fairs the worst, so it will not absorb odor well. None passes the 100 cfm threshold, let alone our 200 cfm benchmark. You will need a little bit of patience with AC4100.

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.

GermGuardian AC4100

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 TypeDecibels
Breathing10 dB
Rustling leaves20 dB
Whispering/ Quiet library30 dB
Light rainfall40-50 dB
Conversation50-60 dB
Vacuum cleaner/ Hair dryer/ Washing machine65-80 dB
City traffic80-90 dB

Pricing And Maintainence Cost

GermGuardian AC4100 MRSP/ RSP
+- 89.99
GermGuardian AC4100 annual filter replacement cost
Annual Filter Cost
+- 48 - 65
^ Replacement filters/ estimated cost
Other than the different variants from GermGuardian, AC4100 it's the few affordable air purifier under 100 that comes with UV-C light technology. If UV light is essential to you, there is no better value air purifier than this. Operational cost is low considering the number of filters that need replacing. While the comprehensive 4-stage filtration is commendable, it adds up to the annual filter maintenance cost between $48-65, or $240-325 after 5 years. The combination filter E set cannot be purchased separately, and you have to replace it every 6 months on regular use.

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

GermGuardian AC4100 VS The Challengers

Hamilton Beach TrueAir Compact Pet Air Purifier 04384 Review

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 Air Purifier Review

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 Review

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 air purifier

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.


  • 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.


  • 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.

Verdicts And Ratings

Build Quality



Particle Filtration

Smoke Filtration


Filter Cost



GermGuardian AC4100 Air Purifier Review

Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.
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