Temperature Change Calculations for Water

Temperature Change Calculations for Water

The BTUs required for changing the temperature per degree per pound

• Solid Temperature Change - .5 BTUs
• Solid to Fluid State Change - 144 BTUs
• Liquid Temperature Change - 1 BTU
• Fluid to Gas State Change - 970 BTUs
• Gas Temperature Change - 1 BTU

Note that State Changes DO NOT AFFECT TEMPERATURE
They only require Energy

• 32F Ice is the same Temperature as 32F Water
• 212F Water is the same Temperature as 212F Vapor

To compute the energy (in BTUs) necessary to raise the Temperature of 5 lbs of 10F ice to 212F vapor, compute for 1 lb first:

• (10 to 32) * .5 = 22 * .5 = 11 BTU
• Change State (ice to water) = 144 BTU
• (32 to 212) * 1.0 = 180 * 1 = 180 BTU
• Change State (water to vapor) = 970 BTU
• Total Energy to change 1 lb = 1305 BTU

Now multiple by weight: 1305 * 5 = TOTAL 6525 BTUs