Now Google in their infinite wisdom things i mean fans as in desktop blowing fan.
To disambiguate either synonyms or homonyms, Google looks at the context of a word. Chances are by now that Google is looking not only at the context of words on your pages... it's also looking at the context of the word on inbound linking pages.
If the vocabulary on your pages is sparse (which it might be if your enthusiast site were, say, a photo gallery), or too heavily focused just on the main keywords, Google might still get it wrong. Disambiguation is a difficult problem. I have certain pet searches I use to test the disambiguation capabilities of a search engine, and I will say that Google gets it right more than any other search engine I've seen.
So I'd look at whether there is enough co-occurring vocabulary on the site (as opposed to the keyword itself) on the page for the context you're intending.
To use the example you provide, one kind of fan suggests an electric appliance, air flow, cooling, blades, material of construction, size, wattage, possible features, etc.
The other kind of fan suggests (as you say) supporters and enthusiasts, following, manifestation of interest, meetups, events, memorabilia, etc. It suggests also that you'd have a set of pages on your site focused on aspects of the particular fandom you're pushing, whether celebrity fandom or the following of a particular hobby, activity, sport, whatever.