# How many BTUs does it take to convert water to steam?

## How many BTUs does it take to convert water to steam?

The water is being changed into steam. This change of state requires a large amount of heat, far more heat than that needed to raise the temperature of the water from 70°F to 212°F. An additional 970 BTU’s is needed to change a pound of water into a pound of steam at atmospheric pressure!

### How many BTUs are in a lb of water?

970 Btu

The temperature will remain constant until all the liquid is changed to “vapor”. The added heat is absorbed in the process of changing from a liquid to a gaseous state. This heat is called the “latent heat of vaporization”. For water, this is 970 Btu per pound.

#### How much is a lb of steam?

One cubic foot of steam weighs 0.03732 pounds, and one pound of steam occupies 26.796 cubic feet at zero psi gauge pressure and a temperature of 212°F. One cubic foot of dry air weighs 0.08073 pounds, and one pound of dry air occupies 12.387 cubic feet at zero psi gauge pressure and a temperature of 0°F.

**What is the energy of 1 BTU to foot pounds?**

778.77 ft-lb

Btu (mean) to Foot-pounds table

Btu (mean) | Foot-pounds |
---|---|

1 Btu (mean) | 778.77 ft-lb |

2 Btu (mean) | 1557.54 ft-lb |

3 Btu (mean) | 2336.31 ft-lb |

4 Btu (mean) | 3115.08 ft-lb |

**How much does a pound of steam weigh?**

## What does pound of steam mean?

A pound of steam is a certain mass; if you condense the steam you would get a certain number of gallons of water (still the same number of pounds, of course). The relationship between the two would be given by the number of pounds in a gallon of water.

### How do I calculate BTU for boiler?

Multiply your square footage by 50 to determine the size of your boiler. For instance, if you house is 1,103 square feet, your heater should be at least 55,150 Btu.