What is the primary effectiveness of applying hose streams on the exposure building compared to simply placing a stream between buildings?

Applying hose streams directly onto the exposure building is highly effective at stopping radiant heat transfer, which is crucial in preventing the spread of fire from an involved structure to a nearby one. When water is applied to the exterior surfaces of the exposure, it creates a cooler barrier that absorbs and dissipates heat. This is particularly important in urban environments where buildings are in close proximity to one another, as radiant heat can easily ignite combustible materials on the outside of an exposure building.

Using a hose stream between buildings might provide some cooling effect, but it often lacks the direct and targeted impact on the surfaces of the exposure. A direct attack on the exposure allows firefighters to protect the structure more effectively while also reducing the overall heat load during firefighting operations. This approach enhances overall fire control efforts, especially when the fire threatens adjacent properties.