About the usage fee of central air conditioning?

Since there is no clause in the contract to pay for central air conditioning, you can of course refuse to pay.

If they say it's a routine, then you can answer why there is no royalty in the contract. Central air conditioning itself is a part of the building, and your rent should include air conditioning cost sharing.

As for the use fee, there is no provision that they can ask for it at will. Why not ask for 60 thousand?

As a consumer, you should have the right to know. Not telling you that you need to spend is cheating.

Don't worry, they won't win.