An empty compressed air can, also known as a duster or compressed air duster, does not require refrigeration for storage. These cans are typically filled with liquefied gas such as difluoroethane or tetrafluoroethane, which turns into a gas when released from the can.
As long as the can is stored in a cool, dry place away from direct sunlight and heat sources, it should last indefinitely. The pressure inside the can will not decrease over time because there is no liquid left to evaporate.
However, it's essential to follow any specific storage instructions provided by the manufacturer to ensure the best performance and safety of the product. Some general tips for storage include keeping the can upright and avoiding extreme temperatures, as exposure to high heat or direct sunlight could potentially lead to increased pressure inside the can, which may cause safety issues.
If you're unsure about the specific storage recommendations for a particular brand or type of compressed air can, it's always a good idea to check the product label or contact the manufacturer for guidance.