Which statement is true regarding domestic hot water temperature in buildings?

Which statement is true regarding domestic hot water temperature in buildings?

• A. It should be delivered at 160 °F
• B. It should be delivered at 120 °F or lower
• C. It should be delivered at 90 °F
• D. Temperature is not regulated

Answer: (B)

Safe hot-water delivery focuses on preventing burns while keeping water practical for use. The standard target is 120 °F (49 °C) or lower at fixtures. Water much hotter than that can cause rapid, severe burns, especially for children and older adults, so delivering at 160 °F is unsafe for regular use. A temperature like 90 °F would be too cool for typical bathing and cleaning tasks, and saying temperature isn’t regulated ignores the safety standards and codes that require control of hot-water delivery. In practice, building operators achieve the limit with devices like tempering or mixing valves and properly set heater thermostats, ensuring the water you actually use at taps stays at or below 120 °F. Some systems may store water hotter for disinfection purposes, but the delivered temperature remains tempered to a safe level.

Safe hot-water delivery focuses on preventing burns while keeping water practical for use. The standard target is 120 °F (49 °C) or lower at fixtures. Water much hotter than that can cause rapid, severe burns, especially for children and older adults, so delivering at 160 °F is unsafe for regular use. A temperature like 90 °F would be too cool for typical bathing and cleaning tasks, and saying temperature isn’t regulated ignores the safety standards and codes that require control of hot-water delivery. In practice, building operators achieve the limit with devices like tempering or mixing valves and properly set heater thermostats, ensuring the water you actually use at taps stays at or below 120 °F. Some systems may store water hotter for disinfection purposes, but the delivered temperature remains tempered to a safe level.