GermGuardian AC4020 3-in-1 Quick Review

GermGuardian AC4020 3-in-1 is yet another affordable, compact speaker alike air purifier from Guardian Technologies. With a well-balanced 4-stage filtration that is not undercut by the price tag, GermGuardian AC4020 will be perfect model for office bound people that hangs around desk far too often. Comparing its air flow delivery rate, applicable area, and filters, what attributes would make GermGuardian AC4020 3-in-1 more standout than other similar field compact air purifier? Head over to our specification and review below.
± 79.99 p
     Annual filter ^    
± 27 - 40 p
Online price*
Latest Amazon price

GermGuardian AC4020 Specification

ProductGermGuardian AC4020
5.75 x 9 x 7.25 in
(14.6 x 22.9 x 18.4 cm)
Weight3.65 lb (1.7 kg)
Coverage (up to)60 sq. ft. (6 m2)
Dust free (CADR)
Pollen free (CADR)
Smoke free (CADR)
Airflow 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 ($)
Ionizer/ Technologies
UV-light/ PCO
UV-A light
Other filter
All-in-one filter
- Lifespan
- Replacement cost ($)
FLT4010 Filter-A True HEPA
6 - 9 months
+- 19.99
Optional/ Addon
Noise level
Power consumption
Timer/ Scheduler
More color options
Auto mode
Air qualityAQ indicator
Filter change indicator
Wi-Fi/ BTBluetooth
Remote control
Child lock
Warranty1 year
Email/ Phone support
Product image

Key features

  • 4-stage filtration with 3 speed
  • Charcoal pre-Filter
  • HEPA Filter (99.97% efficiency rate at smallest 0.3 microns)
  • Optional UV-A technology
  • 1 year warranty

GermGuardian AC4020 review

  • Compact and lightweight speaker alike design.
  • Very affordable price for a 4-stage filtration with UV technology.
  • "True" HEPA filter instead of HEPA-type filter.
  • Optional UV-A light that is a added bonus filtration against bacteria and viruses.
  • Very limited airflow purifying coverage that is only ideal for desktop use.
  • Charcoal pre-filter is not the best against household odor and smoke form particles.
  • Plain vanilla unit with no other convenience features.
  • Only 1 year warranty as opposed to industry standard 3.
GermGuardian AC4020 dimension
5.75 x 9 x 7.25 in
(14.6 x 22.9 x 18.4 cm)
GermGuardian AC4020 weight
3.65 lb (1.7 kg)

A very compact 9 inch model, GermGuardian AC4020 3-in-1 “speaker” air purifier is very small and lightweight yet without neglecting any of the build quality. For starters, GermGuardian AC4020 3-in-1 streamline plastic cover is very straightforward to clean and use with a round front dial knob control. Replacing the filter is also dead easy plus a filter change indicator to remind you when to change the filter. Lastly no timer, Ionizer is available and GermGuardian AC4020 3-in-1 only comes with 1 year warranty.

Airflow efficiency and purifying coverage

Given the price and size, GermGuardian AC4020 3-in-1 is not an air purifier that you should have too high expectation. The very limited air purifying coverage and airflow mean its only meant for room with constrained space. In other words, GermGuardian AC4020 3-in-1 is best utilized in table or work desk. Good news is GermGuardian AC4020 3-in-1 is equipped with a 4-stage filtration including a charcoal pre-filter, HEPA filter and UV-A light. Its total purifying capacity can do away nearby airborne particles within its range like dust, dust mite, mildew, pollen, pet dander and mold.

Noise level and power consumption

A silent air purifier, GermGuardian AC4020 3-in-1 will generates minimal to modest noise that would not intrude with your daily life. Soft noise at minimum fanspeed while modest audible noise at max fanspeed. Very similar to other household appliances, GermGuardian AC4020 3-in-1 generated noise is still within most suitable level that you will be OK to let it run 24 hours a day.As for energy consumption, GermGuardian AC4020 3-in-1 might not have the advantage of Auto mode management, it will not have substantial impact on your electricity bills even if you run it 24×7. Power consumption is minimal at low fan speed and slightly higher at maximum fanspeed. When put next to common home appliances, GermGuardian AC4020 3-in-1 all-round electricity usage is undoubtedly lower given its small airflow distribution.

noise graph

Final thoughts on GermGuardian AC4020 3-in-1

In conclusion, GermGuardian AC4020 3-in-1 is what we would expect from a compact air purifier in this price range. While all air purifiers have their specific pros/cons, GermGuardian AC4020 3-in-1 limited purifying range is probably the deciding factors of considering this unit. Also, consider looking at the alternate GermGuardian AC4100 as well.

Covered against
GermGuardian AC4020 VS Dust



GermGuardian AC4020 VS Pollen



GermGuardian AC4020 VS Hair

Hair/ Pet hair


GermGuardian AC4020 VS Dust mites

Dust mites


GermGuardian AC4020 VS Mold/ Mildew

Mold/ Mildew


GermGuardian AC4020 VS Pet dander

Pet dander


GermGuardian AC4020 VS Virus/ Germ

Virus/ Germ


GermGuardian AC4020 VS Tobacco smoke

Tobacco smoke


GermGuardian AC4020 VS Chemical



GermGuardian AC4020 VS VOCs



GermGuardian AC4020 VS Smoke/ Gas

Smoke/ Gas


GermGuardian AC4020 VS Odor



All in all GermGuardian AC4020 efficient plus purifying coverage and airflow input/ output is brilliant in cleaning out large airborne pollutants specifically hair, dust. up against allergens, irritants, bacteria and viruses, GermGuardian AC4020 comes with , 3 fanspeed and 4-stage filtration is at acceptable grade in eliminating pollen, mold, mildew, pet dander and dust mites.  On odors and smokes, GermGuardian AC4020 filtration is substandard in overcoming chemicals, fire, cooking odors, VOCs, tobacco smokes, cigarette, vapor and radon.

Verdicts and ratings

Build quality
Airflow delivery
Particle Filtration
Smoke Filtration

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