My property manager won't allow me to install a Window A/C despite having a broken Central A/C unit?

My question, is it even legal for him to do this despite the fact that my Central Air Condition Unit is no longer functional? I can't sleep very comfortably in my room, and it normally takes me a couple hours to fall asleep in this humidity. Is there anything I can do to repeal this rule? If it helps, I live in an condominium and pay my mortgage and association fee on time.
Added (1). Simpson, your point would only be valid if installing the A/C was a permanent aesthetic change, it is not, therefore the temporary reduction in property value of the real estate is a moot point. Also, even if it did lessen the property value, is it significant enough to warrant prohibiting home owners from installing Window A/Cs?

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