To reply to an earlier comment in this thread, many cooled automotive seats use peltier modules to pump the heat out. These are the little thermoelectric modules that are used in coolers that you plug into the cigarette lighter, amongst other uses. They're also used in cars with refrigerated console bins, etc. They are solid-state, with no moving parts...apply power, and one side gets hot, the other gets cold. You just blow air over them to remove the heat...ditto, the cold side. They are limited in how much heat they can pump, but they are inexpensive and simple to implement. Originally developed for use in spacecraft back in the Apollo days, if I recall correctly.
Regardless of hardware, the Genesis seats are actively cooled, not just ventilated. I don't know if the Genesis uses the peltier modules or not, but it's likely, as most cars do it this way.
I once posted a comment about why I thought the passenger side doesn't have cooling, aside from the obvious cost implications...I figured that it may be an electric power limitation, considering all of the other power equipment on the car. You don't want the car to get into a state for any length of time where it's discharging the battery faster than the alternator can replace it. If you turn on the lights, rear window defroster, mirror heaters, seat heater and/or cooler, climate control, and the entertainment system, electrohydraulic steering, etc., you're talking about some serious amperage. While some of these wouldn't be used together, the point is that there may be some iffy situations, and Hyundai wants to limit the possibilities to some extent.