Some types of indoor air filters have been getting a bad rap lately: A post at Talkin’ Tech (among other things) reports on a recent study finding that ozone-generating purifiers can actually create dangerous levels of smog in your home. But that same study also found that high efficiency particulate absorbing (or “HEPA”) filters appear to be safe and effective at ridding your house of pollutants. Meanwhile, Mark over at Mindful Musings gives a glowing review to his family’s recently purchased BioFresh HEPA Air Purifier, which boasts a pollen sensor and smell sensor that work together to determine how fast the unit runs. Says Mark:

“The pollen and smell sensors work, which is quite amazing. Cooking makes it automatically run faster and so does Jennifer’s nail polish smell. When the dogs wag their tails near the pollen/dander sensor, the unit wakes up and starts sending more air through.”