If you get a pungent smell from your cooler, then it is because of irregular cycle of changing water. In these coolers, it is mandatory to change all the water in every 2-3 days. Second, clean its pads every 2-3 weeks. Otherwise doesn’t matter which cooler it is or of which brand or how costly, but it will definitely smell foul. No personal cooler brand declares noise levels because they are always high.
It sounds between 70dB-75dB irrespective of its brand and price. Their noise levels are higher than that of washing machines because an average washing machine has 60dB-65dB. If there is humidity in the room when you switch on the cooler, then it is because of ventilation and not the cooler. Proper ventilation is necessary while using personal or dessert cooler. Improper ventilation will definitely cause humidity even if the cooler is working. Switch on the pump for 2-3 minutes before you start using the cooler, and then start the fan.