Typical installation method of split wall or ceiling mounted split type a/c unit, typical wiring diagram of central split type air conditioner, room air condition, and installation detail and wall-mounted Fcu Detail. indoor temperature for design and testing purposes shall be 74 °f(23 °c)when the outdoor temperature 103 °f(39.5 °c). the contractor has to get from the manufacturer certification to ensure that his equipment is complying with the design other wise the contractor will change accordingly on his cost to get compliance with manufacturer requirements.