I have never tried the fan goggles, a bit too pricey for the likes of me lol.
I opted for some basic viper goggles, and i place my lower mesh mask beneth the nose well of the goggles. This creates a little gap for some air to get in. When i did that I never fogged up. could be worth a go.
I know some people buy goggles like my viper ones and remove the inner lining to let air get in. High end paintball masks are really good aswell.
Like most things its trial and error until you find what works, and it sticks