In most cases, it is not recommended to move the window ventilation kit for a portable air conditioner (floor unit) from one window to another or remove it temporarily to allow fresh air to enter your apartment. The window ventilation kit is specifically designed to work with the portable air conditioner and is essential for the unit to function properly.
The window ventilation kit consists of an exhaust hose that removes hot air from the room and vents it outside through the window. This process helps cool down the room by expelling hot air generated by the air conditioner's compressor. If you were to remove or disconnect the exhaust hose, the hot air would remain trapped in your space, causing the air conditioner to work less efficiently or even potentially leading to overheating of the unit.
However, some portable air conditioners have a "fan-only" mode that allows you to use the unit as a regular fan without cooling. In this mode, you may be able to remove the window ventilation kit temporarily to let fresh air circulate into your apartment. However, keep in mind that without the exhaust hose, the unit will not be able to expel hot air outside, so it may still contribute to a slight increase in temperature and humidity indoors.
If you want to allow fresh air into your apartment, it is generally more effective to use natural ventilation techniques such as opening windows, creating cross-ventilation, and using fans strategically to circulate the air.