GermGuardian AC5900WCA True HEPA Air Purifier

GermGuardian AC5900WCA is a true HEPA air purifier that features a multilayered air purification system and is intended for larger rooms and areas in general.

GermGuardian AC5900WCA lacks any form of wireless control and management, but it offers simple use and maintenance, thorough air filtration, including the removal of pet odors, VOCs, smoke, and other air pollutants, commonly found at homes.

Published: March 1, 2021.

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GermGuardian AC5900WCA Features and Specifications

First of all, GermGuardian AC5900WCA is a large unit, and when in use, it should be positioned on a flat surface, preferably on the floor, with at least one foot (~30.5 cm) away from the furniture.

GermGuardian AC5900WCA weighs 13 pounds (~5.9 kg), with physical dimensions of (D x W x H) 9.65 x 15.95 x 20.87 inches (~24.5 x 40.5 x 53 cm) - standing almost 21 inch tall, GermGuardian AC5900WCA is anything but a small air purifier.

Multilayered air filtration system consists of:

- mechanical pre-filter removes the largest airborne particles and protects inner air filters from physical damage and prolongs their lifetime,

- Activated carbon air filter removes pet odors, Volatile Organic Compounds (VOCs), kitchen smells, and other common household odors and smells,

- True HEPA air filter filters out 99.97% of 0.3 microns or larger particles from the air, ensuring that the air purifier releases practically the pure air,

- UV-C lamp in combination with Titanium Dioxide (TiO2) sanitize the air, killing germs, bacteria, viruses, and also removes remaining odors and VOCs from the air. However, the use of UV-C lamps may produce harmful ozone in very small quantities.

Note on Ozone: The 8 hour TWA (Time Weighted Average) Ozone for GermGuardian AC5900WCA is 0.001 ppmv when tested in a 30 m3 chamber - GermGuardian AC5900WCA complies with various maximum allowable concentration of ozone standards, which differs from country to country, by large safety margin. However, GermGuardian AC5900WCA features a UV lamp On/Off switch, allowing the user to turn the UV lamp off/on as needed.

GermGuardian AC5900WCA Console

As said before, GermGuardian AC5900WCA doesn't feature WiFi or Bluetooth connectivity and it does not support the use of Amazon Alexa and/or Google Home Assistant - and many users actually like it because of that.

GermGuardian AC5900WCA console is simple and it allows the user to control the unit via just a few touches.


The console is positioned on top of the unit and it includes:

- Night Light/Filter Reset Switch - used for turning the night light On/Off and for resetting the filter change warning.

- UV Lamp On/Off and UV Lamp Reset Switch - used for turning the UV Lamp ON/Off and for resetting the UV Lamp change warning.

- Timer Switch is used for setting the timer On/Off and for setting the timer length of 1, 2, 4, and 8 hours.

- Fan Speed switch allows the user to set the fan speed - GermGuardian AC5900WCA features three fan speeds.

- On/Off switch turns the unit On and Off.

And that is all regarding controlling the GermGuardian AC5900WCA.

However, no matter how simple to use and maintain GermGuardian AC5900WCA is, when it arrives be sure to thoroughly read the Owner's Guide and to get accustomed to your new air purifier.

When the fan speed is set to maximum speed, GermGuardian AC5900WCA features a CADR rating of 220 for dust, 215 for pollen, and 218 for smoke. Also, as an air purifier, it is suitable for rooms up to 338 sq. ft. (~31.4 m2).

GermGuardian AC5900WCA Maintenance

GermGuardian AC5900WCA is a simple unit to both use and maintain.

Unit should be regularly cleaned using a soft and dry cloth, preferably on the monthly basis, or as required.

The pre-filter screen should be vacuumed using a soft dust brush attachment, also on the monthly basis, or as required.

The main air-filter of the GermGuardian AC5900WCA is GermGuardian FLT5900 Filter J HEPA air filter. It consists of a non-washable activated carbon air filter and a non-washable true HEPA air filter - these air filters should be replaced once every 6-8 months, depending on the unit's use.

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When replacing the air filter, always use genuine air filters since the performances of air purifiers directly depend on the quality of air filters.

GermGuardian AC5900WCA air filters may be ordered using Germ Guardian FLT5900 True HEPA Air Purifier Replacement Filter J Amazon link (link opens in the new window).

For people having the need to fight odors and VOCs, there is also an option of ordering just an activated carbon filter (model FLT22C84 contains 4 activated carbon air filters), which is then replaced more often than a true HEPA air filter.

After replacing the air filters, be sure to reset the filter indicator light.

UV light bulb is another air purifier part that has to be replaced occasionally.

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UV light replacement period depends on the bulb use and many users that use UV light only occasionally don't have to replace the UV light bulb during the lifetime of the GermGuardian AC5900WCA.

After replacing the UV light bulb, be sure to reset the UV light bulb indicator light.

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

germguardian ac5900wca mLong Story Short: If You are looking for a simple and reliable, easy to use and maintain, high-capacity air purifier, consider this unit.

It lacks many advanced features, but that is the reason why so many people like this or similar units.

Also, it comes with very nice 3-year limited warranty.

For more reviews and recommendations, feel free to follow GermGuardian AC5900WCA True HEPA Air Purifier Amazon link (link opens in the new window).