Yes they do, it is not unique to portable aircon. All aircon unit, portable or otherwise require the venting of hot air during operation to complete the cooling process. Simply put, you got to have the cool air coming out front of the unit and have an equal amount of hot air expel from the back. You if do not channel out the hot air out of the window that you trying to cool, you won't be able to cool the room. This is why all portable air-con that we offer in our website, will include exhaust hose, window kit panel that is easily installed for most standard size windows.
The portable air-con we offer is capable to internal process and evaporate the collected moisture so you do not have to worry about manually draining them. Keep in mind that, there are occasion when the humidity in an particular environment makes the unit incapable of processing it. In those cases, the excess water will be collected in an internal storage pan. Once it is filled up, the system is design shut down to prevent leaking. In rare cases, you will need to manually drain from the back of the unit.
We find this question quite challenging to answer as noise level can be subjective. One man noisy can be another man quiet. Since portable aircon contain a fan and a compressor all in the same housing. We found that the noise level is very similar to the window aircon that we already heard before. All portable aircon listed in our website will indicate the Decibels (DB) reading. The lower the DB reading, the more quiet the unit will be.