A fan moves air. If anything, the energy needed to move it would slightly warm it even (but that can be ignored). How should it improve air quality? It can neither turn CO2 into O2 nor can it get rid of smells nor can it reduce humidity. It moves air around. Nothing more.
A fan doesn’t cool your apartment or improves the air quality. Maybe you should smoke less, it seems to degrade your brain functions.
A fan can literally do both.
A fan moves air. If anything, the energy needed to move it would slightly warm it even (but that can be ignored). How should it improve air quality? It can neither turn CO2 into O2 nor can it get rid of smells nor can it reduce humidity. It moves air around. Nothing more.