Noise levels can vary between models, and it's important to choose a unit with a noise level that is tolerable for the intended usage, especially if the air conditioner will be used in bedrooms or other quiet areas. Look for models that feature a low-decibel operation or include noise-reducing technologies.

Portable air conditioners are usually labelled with an energy efficiency rating that indicates their energy saving capabilities and helps users make informed choices about their efficiency. In Europe, the energy efficiency of portable air conditioners is usually indicated by the European Energy Efficiency Certificate. This certificate uses a scale from A+++ (most efficient) to D (least efficient). Countries such as the United States and Australia use their own energy labelling systems, such as the Energy Star rating and the Energy Rating Label respectively. Choosing models with higher energy efficiency ratings can help minimise electricity costs and reduce the environmental impact of their use.