The present paper reviews results from an extensive large-scale fire test series including computational three-dimensional time-dependent simulations. The aim of the study was to achieve knowledge of the effect of water as a fire mitigation and extinction means as such and investigate if water monitors could replace conventional deluge systems, and if so, under which conditions. Additionally to qualify the CFD code Kameleon FireEx KFX® as a validated tool for analysis or design of water based fire mitigations systems and develop proposals for input to a guideline for use and design of deluge and monitor systems. A large-scale outdoor test facility (15 m × 10 m × 10 m) was built for this project, and both gas jet fires, diesel spray fires and pool fires in complex and rather congested geometries have been tested. The effect of deluge on different fires was tested and compared with the effect of several monitor solutions as well as use of additives to water in deluge and monitor solutions. More than 50 tests were executed. All, except for some tests with special additives, have been simulated by KFX®. Temperatures, both in the gas phase and at solid surfaces, were measured at 200 locations for each test and compared with computations. The water droplets seem to have a moderate effect on flame temperatures but significant effect on structural and equipment temperatures. The paper reviews in detail the results for a selected number of cases. The agreement between experiments and computations is in general very good.