Austin Air The Pet Machine

The Austin Air Pet Machine is nearly identical to the top-rated Austin Air HealthMate (*Est. $490) with one exception: The Pet Machine's carbon filter includes additives designed to better absorb ammonia (urine) pet odors. Some users say this works well, while others complain that it's ineffective on odors, but it's hard to draw a conclusion because experts have not tested it objectively against other machines. Furthermore, only a few owners have posted reviews. Some experts give The Pet Machine high marks for the same reasons that they like the HealthMate. It uses HEPA filtration that has been proven effective at capturing dust, pollen, mold spores and pet dander, plus it has carbon to filter the tinier particles of chemicals and odors in the air. Austin Air's good reputation and five-year filter warranty are also pluses. However, experts and users say Austin Air purifiers -- including The Pet Machine -- are heavy and noisy.

Experts at AllergyBuyersClub.com base their endorsement of The Pet Machine largely on its features and the good reputation of Austin Air. Reviews at ConsumerGuide.com and AchooAllergy.com appear to be likewise based on features, not testing. A couple of owner reviews at Amazon.com are at odds with owner reviews at AllergyBuyersClub.com and AchooAllergy.com.