A system using some open and some closed sprinkler heads is a variation of which type of system?

A system that utilizes both open and closed sprinkler heads is known as a deluge system. This system is characterized by being equipped with open sprinkler heads that are not capped but are activated by a fire alarm system. When a fire is detected, the deluge system releases water through all open heads simultaneously, providing immediate coverage over a larger area. The closed heads, on the other hand, remain sealed until the temperature in their vicinity reaches a critical threshold, allowing water to flow once activated.

The presence of both types of sprinkler heads is essential in a deluge system because it allows for greater flexibility and effectiveness in suppressing fires by ensuring that the water is distributed to areas that are most at risk while also allowing for a controlled response in other areas. This makes the deluge system particularly useful in environments where rapid fire spread is expected, such as in warehouses or industrial plants with flammable materials.

Other types of systems such as wet or dry systems operate on different principles and do not typically integrate both open and closed heads in the same manner. Wet systems maintain water in the pipes at all times, while dry systems use pressurized air to keep water from entering the pipes until activated. The pre-action system, meanwhile, is a hybrid that usually incorporates