What did old-style sprinkler heads do that new style heads do not?

• A. Direct water onto the floor
• B. Direct some of the water onto the ceiling
• C. Release gas upon activation
• D. Make noise when activated

Answer: (C)

Old-style sprinkler heads used a gas-filled actuation mechanism. When heat activated the head, the internal gas helped push the valve open and start water flow. Newer heads do not include that gas component; activation relies on the water pressure itself to release the valve, so no gas is vented. That difference—releasing gas upon activation—is why this choice best distinguishes older designs from newer ones. Water distribution from the heads and whether they make noise aren’t reliable features that separate old from new, since both types are designed to deliver water through the deflector and can vary in noise depending on conditions.