Friedrich C-90B Review

What the reviewers like:
Owners and reviewers agree that the Friedrich C-90B does a terrific job cleaning air and runs fairly quietly.

What the Reviewers Don’t Like:
Cleaning the Friedrich C-90B can be a chore, and the cost of replacement filters adds up. More than a few owners complain about strange popping and snapping noises, and some have concerns about the small amount of ozone this electrostatic machine produces.

Friedrich C-90B review highlights

Owners and experts generally agree that the Friedrich C-90B does a good job cleaning air; this air purifier ranked first in a thorough comparison test by one major magazine. However, we did find some comments about the need for constant maintenance (the pre-filters and carbon filters need to be replaced every few months, at $20 a pop, while the electrostatic plate has to be cleaned in the sink or dishwasher), and more than a few owners complain about strange popping and snapping noises. In addition, the Friedrich air purifier emits a small amount of ozone as it works. Experts agree that ozone can be an irritant, and since there are so many good units on the market that don't produce ozone, you're better off passing on the Friedrich model. The Alen A350 (*est. $400), for example, works without producing any ozone.

The Friedrich C-90B isn’t lacking for attention: this electrostatic air purifier is included by Consumer Reports in its most recent category roundup (in November 2007), and its predecessor, the similar C-90A, is evaluated by AllergyBuyersClub.com. The Friedrich C-90B is also described in depth at Air-Purifier-Power.com, and receives some posts from owners on Amazon.com and Epinions.

Also see full report: Air Purifiers

*In order of credibility (see our Ratings Criteria).

1. Consumer Reports
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Air Purifiers
Editors of Consumer Reports
Nov. 2007

The Friedrich C-90B is pitted against 35 other air purifiers in Consumer Reports’ most recent roundup (November 2007). Editors note that electrostatic precipitator air purifiers like the Friedrich so emit a small amount of ozone gas as a byproduct, and that ozone, even in small amounts, can be an irritant.

2. Allergy Buyers Club.com
Air Cleaners -- Friedrich Electrostatic
Editors of AllergyBuyersClub.com

The editors of AllergyBuyersClub.com acknowledge that the immediate predecessor to the Friedrich C-90B, the C-90A, looks like a "giant kitty litter box," but say it’s quiet and easy to maintain. However, they don’t recommend it for severe asthma or allergy sufferers because this unit does emit some ozone.

3. Air-Purifier-Power.com
Friedrich C-90B Air Purifier Review
Ed Sherbenou

Reviewer Ed Sherbenou -- who owns numerous air purifiers, and knows plenty about the ones he doesn’t -- calls the Friedrich C-90B a "top-quality electrostatic air cleaner," but says it has high ozone emissions and requires frequent maintenance of its plate filters.

4. Amazon.com
Friedrich C-90B Electrostatic Air Purifier Review
Contributors to Amazon.com

Most of the owners posting at Amazon.com are very happy with the Friedrich C-90B, but there’s some grumbling about the need for frequent cleaning and the cost of replacement filters ($70 every few months, according to one user). There are also some complaints about odd "snapping" noises.

5. Epinions
Friedrich C-90B Air Purifier Review
Contributors to Epinions

When we checked, there was only one review of the Friedrich C-90B at Epinions, which mentions the snapping noises cited by owners posting to Amazon.com. This owner also complains about the cost of pre-filter and carbon filter replacements.

Also see full report: Air Purifiers

Friedrich C-90B Review