With aircon turned on both fans normally run even with cold engine, the fans go on and off with compressor clutch, the LH fan ( from driver seat ) is engine cooling, which I have to say has never come on on its own on any of our Honda cars, but on my wifes Fiat used to come on regularly and used to come on and stay on for several minutes every time the ignition key was removed.. RH fan is aircon but I don't know why they both come on together - maybe to stop hot air from aircon radiator being blown back through engine radiator ?