Final answer:
Fire sprinkler systems are installed where a wet pipe system cannot be heated to prevent freezing.
Step-by-step explanation:
Fire sprinkler systems are installed where a wet pipe system cannot be heated to prevent freezing. In areas where temperatures drop below freezing, it is necessary to prevent the water in the pipes from freezing and causing damage to the system. Wet pipe systems have water constantly present in the pipes, which can freeze and lead to burst pipes. In such cases, a different type of system called a dry pipe system or an antifreeze system may be installed.