Florida law requires that tenants follow a statutory process to withhold rent, and that process only applies when there is a severe problem with the unit affecting habitability. See Florida Statutes Sec. 83.51, 83.60. There is no law in Florida that requires air conditioning to be offered at all, let alone that makes it a component of habitability.

The fact that your landlord does not have to provide air conditioning is a separate issue from your landlord's duty to repair an air conditioner that was provided as part of the tenancy, unless the duty to repair the A/C was modified by the lease. But in the absence of a problem of sufficient severity to trigger the rent withholding statute, we're talking about the possibility of (for example) a legal action to seek a partial rent abatement.