Nope.... I have no fans or any kind of ventilation either, I don't need it.... All that ventilation, fans and such is HIGHLY overated IMO. Trooper helmets may be a different story, but I have never had a problem with a Fett helmet, even in 95+ degree 100% humidity days.
I'm going to add fans to my movie sized helmet, but only because I'll have room for them now. I never had them in my DP helmet and only had a few fog ups. Those were mainly from going in and out of an air conditioned building on a warm day. Get some anti-fogging spray or wipes that they make for motorcycle helmets and goggles as some added insurance. I think you can find it at places like LensCrafters, too.
I wore a DP Dlx (thanks Dean) at Dragon Con last year and I was VERy glad to have the fan in it. With all that padding and fuzzy cloth they have in that thing it feels like an oven and will fog over in seconds. The fan was a lifesaver. Now for these new helmets that are bigegr and not so claustrophobic, the problem may not be near as bad.
I have to have fans in my helmet, I made the mistake of making a seal that closes off the bottom of the helmet completely. The fans worked once since I built the thing, and they worked pretty well. Since that one time, I have had the darn wires break off, so I don't seal the bottom of the helmet off when I wear it ... or I don't breath ... one or the other