Door closers are widely used for doors in commercial buildings, not only for safety purposes but also for reducing the airflow through door openings. This study aimed to develop a method for quickly assessing, in the design phase, the heating and cooling energy cost saving from using an effective door closer. The method developed in this study consists of a stop angle model, airflow model, and energy cost calculation. This investigation also conducted experimental measurements in a full-scale test facility to validate the models. This study then used the proposed method to assess the heating and cooling energy cost saving from using an effective door closer in the cities of Minneapolis, Boston, San Francisco, and Phoenix. It was found that, under a greater indoor-outdoor pressure differential, using an effective door closer would save more energy cost. When using a closer with a larger size, the energy cost lost would decrease, but a large closing torque may significantly reduce ease of use and accessibility and potentially violate building codes related to the Americans with Disabilities Act (ADA). Furthermore, the energy cost saving from using an effective door closer in San Francisco would be lower than that in Minneapolis, Boston, and Phoenix. (C) 2016 Elsevier B.V. All rights reserved.