# How many BTU's do I need for my hot water heater?

A common input is 34,000 BTUs on a 40-gallon tank and 36,000 BTUs on a 50-gallon tank. The higher the BTU input and efficiency, the faster the recovery. Electric water heaters typically have one 5,500-watt or two 4,500-watt elements.
A.

### How many BTUs does it take to boil one pound of water?

lbs of water x temperature rise = BTUs required for one hour (1 lb of water x 1 degree Fahrenheit) = 1 BTU for 1 hour.
Water equals 8.3 lbs per gallon. To boil one gallon of water starting 70°F in 1 hour you will need 8.3 x (212-70) = 1,178.6 BTUs.
• #### How many BTU's are in one pound of steam?

1 pound of steam is equal to 970 BTU (or an easy to remember rule of thumb is 1 pound of steam is equal to 1000 BTU. 1 pound of water is equal to a 16 oz tall boy (by volume)….when you heat that tall boy hot enough to make steam it expands almost 1700 times its original volume.
• #### How hot can you get water?

Superheated water is liquid water under pressure at temperatures between the usual boiling point, 100 °C (212 °F) and the critical temperature, 374 °C (705 °F). It is also known as "subcritical water" or "pressurized hot water."
• #### What temp does steam occur?

At lower pressures, such as in the upper atmosphere or at the top of high mountains, water boils at a lower temperature than the nominal 100 °C (212 °F) at standard pressure. If heated further it becomes superheated steam.
B.

### How many kilowatts does it take to heat a gallon of water?

Energy required to heat one gallon of water, and one tank of water. Heating a gallon of water by 1°F with no losses thus takes 8.33 lbs x 1 Btu/lb = 8.33 Btu's. Heating a gallon of water by 1°F with no losses thus takes 8.33 ÷ 100,000 = 0.00008.33 therms. One kWh is 3413 Btu's, so one Btu is 1/3413 = 0.000293 kWh.
• #### How many Btus does it take to raise 1 gallon of water 1 degree?

A British Thermal Unit (BTU) is a measurement of heat energy. One BTU is the amount of heat energy required to raise one pound of water by 1ºF. Water weighs 8.33 pounds per gallon so we can calculate that one gallon of water requires 8.33 BTU to raise the temperature 1ºF.
• #### How many watts does a freezer use?

Older freezers will use over 100% more energy than newer Energy Star rated models, a modern freezer will use between 100 and 400 watts of power, with 200 watts on average. Click calculate to find the energy consumption of a standalone freezer using 200 Watts for 24 hours a day @ \$0.10 per kWh.
• #### How many watts does a 32 inch TV use?

A 19" TV uses about 80 watts, way less than just about any modern TV. LCD (and LCD/LED). This is the same type of screen that goes in laptop computers and modern computer monitors. Much more efficient than CRT, they use about 125, 210, and 280 watts for the 32", 42", and 52" sizes respectively.
C.

### How many BTU's does it take to boil a gallon of water?

A BTU (British Thermal Unit) describes the amount of energy to raise 1 lb of water 1 degree Fahrenheit in one hour. Water equals 8.3 lbs per gallon. To boil one gallon of water starting 70°F in 1 hour you will need 8.3 x (212-70) = 1,178.6 BTUs.
• #### Why does the temperature of boiling water stay the same?

Temperature and Boiling. When boiling occurs, the more energetic molecules change to a gas, spread out, and form bubbles. In addition, gas molecules leaving the liquid take away heat energy. Therefore the temperature of the liquid remains constant during boiling.
• #### How do you evaporation and boiling differ?

Evaporation and boiling are both processes that take place in liquids where a change of state occurs liquid → gas. When evaporation occurs, particles only change into gas at the surface of the liquid. When boiling occurs particles change from liquid to gas throughout the whole liquid.
• #### What is the difference between evaporation and boiling point?

Evaporation usually occurs on the surface. Evaporation may occur when the partial pressure of vapor of a substance is less than the equilibrium vapour pressure. Boiling is a phase transition from the liquid phase to gas phase that occurs at or above the boiling temperature.

Updated: 6th December 2019