I really hate to get into this but the keyboard is not used as a vent and this is obvious for two reasons:
1) Clamshell mode.
2) The GPU/CPU/North Bridge are , yes, under the keyboard area, but heatpipes move the bulk of the heat from that area to the heatsinks which are then cooled off by the fans , blowing the hot air outward in the back vent.
1) Clamshell mode.
2) The GPU/CPU/North Bridge are , yes, under the keyboard area, but heatpipes move the bulk of the heat from that area to the heatsinks which are then cooled off by the fans , blowing the hot air outward in the back vent.