Guessing the diameter of a drop at 1mm, and assuming it to be cubic, that is 60 cubic mm per hour. Rounding up, we get 1 cc per hour. A U.S. teaspoon is just under 5 cc. Alternatively, get a small cup of water every 24 hours.
There can be about 30 cc of water in a cubic meter of air, so you would have to pump 16 cubic meter of air through this thing and extract all the water to get at 500cc per hour. With a 10 by 10 cm opening, that is a 1600m long column. A bicycle can easily do ten times that speed, so that sounds doable, but that is at maximum efficiency and the article doesn't say he has done that, so I fear that 500cc is wishful thinking.
"Under the right climatic conditions, Fontus can easily produce half a liter of water in an hour's time."
We already know that it can produce half a liter per hour, but those same climatic conditions are when a cyclist needs significantly more than half a liter per hour.
I still doubt that number. Looking at http://atmosphericwatersolutions.com/wp-content/uploads/2012..., I see a machine that weighs 38 kg, consumes 373W of power, and produces 'up to 17 liters of water a day'. This thing would be an order of magnitude smaller, and produce almost the same quantity of water. Possible? Maybe. Likely? No. Because of that, I would like to see experimental confirmation of that half a liter per hour before accepting it as a given.
Also, see http://en.m.wikipedia.org/wiki/Atmospheric_water_generator which claims the U.S. army and FEMA use a system that needs a gallon of fuel for 'up to' five gallons of water. If something like this were known to be more efficient, I think it is likely they would use it.
I'm guessing this is limited by how much cooling you can get out of it.