A
fresh air dehumidification device of a PTAC includes a cross-flow fan, a main
evaporator, an air supply channel communicated with the cross-flow fan via the main
evaporator, and an air exhausting device formed in the air supply channel for supplying air to the main
evaporator. The air inlet of the air supply channel is connected to outdoor and the air outlet of the air supply channel is formed on a first air intake of the main evaporator.
Fresh air passing through the air supply channel and the air exhausting device and is dehumidified by the main evaporator and then flows into the indoor so that the main evaporator of a PTAC is used as a dehumidifier in the dehumidification process, but without needing to increase a separate dehumidification
system. So, the structure of the present disclosure can reduce the manufacturing cost of the PTAC.