If HW supply temperature is 135°F and CW incoming temperature is 55°F, what is the temperature rise?

If HW supply temperature is 135°F and CW incoming temperature is 55°F, what is the temperature rise?

• A. 60°F
• B. 80°F
• C. 140°F
• D. 100°F

Answer: (B)

Temperature rise is the difference between the hot water outlet and the incoming cold water. Subtract the incoming temperature from the supply temperature: 135°F − 55°F = 80°F. So the rise is 80°F. The other numbers would come from incorrect arithmetic or mixing the temperatures in the wrong way.

Temperature rise is the difference between the hot water outlet and the incoming cold water. Subtract the incoming temperature from the supply temperature: 135°F − 55°F = 80°F. So the rise is 80°F. The other numbers would come from incorrect arithmetic or mixing the temperatures in the wrong way.