Liquid Lumens?

I stumbled upon a liquid-cooled hood from a local hydroponics store online. I am looking for a little help as to how this works, if anyone has basic experience with these types or how small of a scale I could run maybe for just one 400/600w hps.

1) How does exactly does the hood itself work? Obviously the bulb does not come in contact with the water so how exactly does it cool the lighting?

2) What size chiller and resevoir would I need for a small grow (i.e. one light).

I saw a ad on the craigslist for a free pickup of a water chiller so this and the fact that my plants are almost ready for flower and I'm researching for the new grow room is whats leading me to the helpful people here for help.

Texas weather so outside temps are avg. 80 degrees (F) and indoor around 70. I'm just not sure routing the fans in my new place is gonna cool anything down since i dont have really anywhere to vent the hot air now, unlike the attic I had before. Just curious thanks!