if the recirculation fans are inop there will be no change in fuel consumption but a reduction in overall air flow through the cabin.
But that is not what they write in the systems description. This is what the FCOM says:
The recirculation fan system reduces the air conditioning system pack load and the engine bleed air demand.
FCS, anymore info on the source of the alleged 20 kgs/hour? I completely agree that it sucks, and that is the reason for my inquiries, I would like to be able to defend turning it off.
The quote with "heating" in bold that refers to the exhaust air for the equipment cooling is obvious. But it still remains unanswered how the recirculation fan(s) contribute to the temperature of hold 1?