I am designing a small test chamber (8 Cubic ft) for testing lithium ion batteries (48 at a time). We could like to add a water mister in case of a fire. I am trying to determine how much mist I need to suppress a fire in case of a thermal runaway. What is the proper method of determining this? Should I calculate this based on how much mist or steam is needed to achieve a non-combustible environment or based on the amount of cooling that is needed since battery fires are self oxidizing? How could I determine how much of the mist will turn to steam with a given fire size? Is there another method I should be using or standard that I should follow for this? I read NFPA 750 but didn't see anything applicable.
The chamber will be located in a room that is built to appropriate NFPA standards and this is test equipment so it isn't necessarily required to meet any NFPA standards but I would like to be sure that we are going about this properly.