Photograph: Kat Merck

I was not able to discern any difference between the two models, either physically or in performance. I started out using the original Shelfy but immediately switched to testing the Shelfy 2 when it arrived. Since most testing was conducted with the 2, all references to “Shelfy” henceforth refer to that device.

As for how the photocatalysis works, a fan draws air into the device, where it is forced between the treated ceramic filter and 12 blue LED lights and “cleansed” by a reaction caused by the two. A video from Vitesy compares the process of photocatalysis to chlorophyll-based photosynthesis, in which water and carbon dioxide are transformed into purified air.

(Note that food is packaged here, but was not during much of the testing)

Video: Kat Merck

Photocatalysis is increasing in popularity for both water treatment and air purification , so a refrigerator does present an interesting use case.…