Mechanical equipment and outside appliances
shall be elevated to or above the design flood elevation.
Exception: Where such equipment and appliances are
designed and installed to prevent water from entering or
accumulating within their components and the systems are
constructed to resist hydrostatic and hydrodynamic loads
and stresses, including the effects of buoyancy, during the
occurrence of flooding up to the elevation required by Section
R322 of the International Residential Code, the systems
and equipment shall be permitted to be located below
the elevation required by Section R322 of the International
Residential Code. Electrical wiring systems shall be
permitted below the design flood elevation provided they
conform to the provisions of NFPA 70.