The feasibility of using water to protect buildings from heat
radiated from an adjacent fire is examined. Two means of applying
the water are discussed, one as a radiation water spray, and the
other as a film on those parts of the surfaces of the buildings which
require protection. It is shown that for equivalent protection, the
surface film theoretically requires less water than the radiation
curtain. The reason for this is that the falling velocity of films
are controlled by the flow of water itself, whereas the falling velocity
of a spray depends on the drop diameter which cannot be reduced to a
value low enough for efficient use in this application.