Series of experiments in a large scale test room with fire vents have been carried out at the Swedish National Testing and Research Institute. Simultaneously, series of field model calculalations were carried out at the Lund Institute of Science and Technology. The main objective with the experiments was to validate the field model performance in a large test room, both with and without fire vents, by measuring the temperature and velocity field at different locations in the room and in the fire vent opening. This report gives the experimental setup and procedures, together with the experimental results. Some preliminary conclusions have also been drawn from the experiments. There is a possibility that venting reduces the temperature beneath the ceiling and hence increases the time to operation of the sprinklers. The observed effects were generally of a nature, which is probably out of range for zone models, but possible to predict with field models. Both projects are parts in a larger research program sponsored mainly by the Swedish Fire Research Board.