Let's go back to your original claim, shall we? You stated:
Both a/c and air circulation take up significant sums of fuel. Perhaps this is a cost saving measure?
It is actually a common practice for airlines to ask flight/cabin crews to adjust cabin temps in order to save fuel
Now you say as if victorious:
Nothing what you wrote above negates the fact that aircraft have a/c cooling packs and that air used in cabins is cooled
How is that in any way related to your original point, and where did I claim otherwise? You've wandered off the path.
I am trying to take you step-by-step through a path which will show you your error in thinking, since I don't think all at once is going to work here. But here we go.
1) There air outside is cold. The aircraft gets cold. It must be warmed up.
2) The air from the engines is hot. Very hot. It can be used to warm the cabin.
3) The air from the engines is actually TOO hot - usually over 200 degrees F. It needs to be mixed with outside air, or cooled down somehow. The manner of this is not relevant to this discussion (though they're usually not running an air conditioner, but I digress)
4) Your claim is that cooling the air down from 200+ to 73, instead of say, 75, causes additional fuel burn that is measurable and impacts El Al's bottom line.
5) I say that shows a lack of critical thinking.
Are we on the same page now?