TThe Open Calorimeter is used for large-scale testing of fires. We employ Oxygen depletion or CO2 generation method to estimate the heat release rate. Open Calorimeter has a distinct advantage over Cone Calorimeter that large fires can be tested; in our case up to 200kW. Open Calorimeter also allows for complex geometries to be tested. A wide range of fuel types, across solid, liquid and gases can be used to set up a fire. The facility also has provisions to study fire suppression on a large scale which come closest to the real-life fire accidents. Sprinkler count, capacity, and configuration can be analyzed for their effectiveness in fire suppression. The reduction in the heat release is estimated to deem whether the suppression method was successful. Emerging firefighting methods like water mist fire suppression are also undertaken.