Air Conditioners (ACs) in office buildings consume so much energy that the Chinese government enacted a regulation to limit the temperature setting range. To evaluate its effectiveness and provide clues for new behavior change methods, the study surveyed 527 office workers' knowledge of the compulsory approach, temperature sensation and preferences. The latter is included to evaluate the reasonableness of the regulation. Their actual behaviors covered in this survey include factors influencing temperature setting, operating patterns in setting, and readjusting behaviors after setting. The aim is to find possible ways to encourage higher temperature setting and correct operation. The results show that although the regulation is reasonable (within the [26 degrees C to 28 degrees C range), more than half of the users violate it with an average setting at 24.9 degrees C. The low awareness of the regulation (31.9%) can only account for part of the ineffectiveness: people with knowledge set higher, but still below 26 degrees C. The survey also found some non-comfort motivations that can be potentially used to encourage higher temperature setting: personal health, noontime napping, connecting with nature, and protecting the environment. On the contrary, office workers would set the temperature lower when they first entered the office. It should be noted that office workers strongly consider colleagues when setting the temperature, but generally do not consider electricity consumption. Some of their operating patterns should also be paid attention like setting a low initial temperature; and constantly shutting off and turning on the AC. The discussion includes applications of these findings in terms of enhancing user motivation and simplifying thermostat operation. (C) 2013 Elsevier B.V. All rights reserved.