How long should I run my air purifier to achieve optimal air quality in my living space? Is there an ideal duration that balances efficiency with energy consumption? Considering various factors such as the size of the room, the type and brand of the purifier, and even the level of pollutants in the environment, what might be the most prudent approach? Should I operate it continuously throughout the day or only during specific hours? Additionally, how do external conditions, like the presence of pets or smoking indoors, influence the required runtime? Furthermore, for those who might be sensitive to certain allergens or pollutants, is there a recommended amount of time that would ensure a healthier atmosphere? At what point does running the air purifier become an unnecessary expenditure? Essentially, what are the best practices when it comes to determining the appropriate duration for running an air purifier effectively? Can individual circumstances significantly alter the general recommendations?