This seminar introduces the experimental approach and selected test sites used to update the heat gains and diversity factors for different office equipment in the ASHRAE Fundamentals handbook tables. The seminar gives an overview on the data logger’s selection criteria for measurement and calibration purposes as well as the testing duration for different equipment. An overview of the experimental results for both, heat gains and diversity factors is also given. Transient data is shown and some typical and atypical findings are pointed out.