You should use a vaporizer anytime you want a clean moisture-freshened scent in a given area without having to resort to spraying air fresheners everywhere which can be harmful to the environment and especially your health if you're sensitive to these types of products. Vaporizers are also great for outdoor areas because they will help control the humidity around your campsite and even inside of places like your tent so you don't wake up in a soggy mess from all the condensation that forms overnight.