From the 2010 Florida Building Code Energy:
REPLACEMENT HVAC EQUIPMENT
220.127.116.11.1 Duct sealing upon equipment
At the time of the total replacement of HVAC
evaporators and condensing units, all accessible, (a minimum of 30 inches
clearance), joints and seams in the air distribution system shall be inspected
and sealed where needed using reinforced mastic or code approved equivalent and
shall include a signed certification by the contractor that is attached to the
air handler unit stipulating that this work has been accomplished.
1. Ducts in conditioned space.
2. Joints or seams that
are already sealed with fabric and mastic.
3. If system is tested and
repaired as necessary.
18.104.22.168.2 Replacement equipment sizing
An AC contractor or licensed Florida PE shall submit a nationally
recognized method based sizing calculation to the code official at the time of
permit application for total replacement of the condensing and evaporator
components of HVAC systems in accordance with Florida law and the provisions of
Section 403.6.1 or Section S03.2.1, as applicable.