PS-121D Comfortaire 12,000 BTU Portable AC Single Pipe w/Window Kit EER 8.9 PS121A PS121B PS121C

There is a reference that the hose may be extended up to 10', however, it does risk losing efficiency and possibility of not operating properly. The hose part number is 12120600A12675.

From manual: The energy rating and noise information for this unit is based on the standard installation using
an un-extended exhaust duct (Diameter: 6 in., Length: 60 in.) without window slider adapter or
wall exhaust adapter A.
The unit with 10 feet extended exhaust duct is running by using 2 exhaust ducts (Diameter: 6
in., Length: 60 in. + Diameter: 6 in., Length: 60 in.). The Energy rating and noise information for
unit with 10 feet extended exhaust duct is not assessed. (For some models)
NOTE：We recommend that operating the unit at room temperature below 95°F . Since there is
a risk that the unit with 10 feet extended exhaust duct would not work at room temperature
above 95°F under some extreme conditions, such as the lower air intake be blocked for 50%.