Fans are actually surprisingly cheap to leave running. If you were to leave a fan on for a whole month, on average it would cost 5$. In comparison, an air conditioning unit would cost around 432$. And that is pretty much the reason why you should consider just using multiple fans instead of an air conditioning unit. However do keep in mind that fan positioning matters alot. The only real downside is that fans appear a whole lot more dangerous.
Keeping a fan blowing directly at you can however cause dry skin and minor irritation. Additionally fans can worsen a cough as they tend to dry the air.
A big advantage is that fans can't cause hypothermia as they don't cool the air, they just circulate it.