Erm... yes it will? Aft and bulk cargo heat use bleed air directly, any increase in bleed usage will increase fuel consumption, no?
And as for the forward cargo A/C selector - its a temperature zone like any other in the cabin, but switching it off will close the FWD Cargo A/C SOV and thus reduce pack load which in turn should reduce fuel consumption somewhat. Whether its significant or not is a different question of course...
Last edited by STBYRUD; 24th Jun 2014 at 11:56.