Long answer: It depends on the temperature of the water you start with. Before you can evaporate the water, you must heat it to it's boiling point. The warmer the water you start with the fewer BTUs will be needed to heat the water to its boiling point. Keep in mind the BTUs require to raise the water to its boiling point are very few compared to the BTUs required to change the water from a liquid to a gas.
One pound of steam contains 1150 BTUs. This is the energy you need to put into the water for it to evaporate if you start with water at 32F. If you start with water at 100F the water already has 70 BTU/lb so the BTUs required to evaporate the water when you start at 100F is 1150-70 = 1080 BTU and so on.
You can get all this information in a steam table which can be found easily by searching the web.
Any amount of heat will evaporate water, it just takes longer with less heat.
I'm leaving the above answer to illustrate a common misunderstanding. "Heat" in chemistry and physics has a specific meaning that may be different from what most people mean by heal.
The specific heat of vaporization of water is about 2250 kJ per kilogram. This is quite close to 1 megajoule (1000 kJ) per pound.
Quick Answer: About 2,139 BTU/litre at the normal boiling point.
Long answer: It depends on the temperature and pressure of the water you start with. Before you can evaporate the water, you must heat it to it's boiling point. The warmer the water you start with the fewer BTUs will be needed to heat the water to its boiling point. Keep in mind the BTUs require to raise the water to its boiling point are very few compared to the BTUs required to change the water from a liquid to a gas.
One litre of water weighs about 2.205 lb, and since both BTUs and lb are from the imperial set of units, we can make the rest of this explanation in terms of pounds and then just multiply by 2.205 when we get done.
One pound of steam contains 1150 BTU/lb relative to liquid water at 32 °F. This is the energy you need to put into the water for it to evaporate if you start with water at 32 °F. If you start with water at 100 °F the water already has 70 BTU/lb so the BTUs required to evaporate the water when you start at 100 °F is 1150-70 = 1080 BTU/lb and so on.
You can get all this information in a steam table which can be found easily by searching the web.
There are 1078.9 BTUs.
2000
On average it takes about 1,600 BTUs to heat 50 square feet. Multiplying 50 by 1600 equals about 80,000. Therefore, the heating plan of 1,600 square foot are would take about 80,000 BTUs.
1MW = 1000 KW 1KW = 860 Kcal/Hour 1 Kcal = 3.968 BTu.
1 gal of #2 fuel oil (or diesel for that matter) has an equivalent of 115,000 BTUS. I say equivalent because it has a little more than that raw (like 136k or so) but the furnace that burns it is only around 85% efficient, therefore you only get 115K BTUS.
It takes approximately 144 BTUs to change one pound of ice at 20°F to water at 212°F, and an additional 970 BTUs to change the water to steam at 220°F, for a total of 1114 BTUs.
It takes approximately 970 BTUs to convert one pound of water at 212°F (100°C) to steam at the same temperature.
144
LATENT HEAT OF FUSION When one pound of ice melts, it absorbs 144 BTUs at a constant temperature of 32°F. If one pound of water is to be frozen into ice, 144 BTUs must be removed from the water at a constant temperature of 32°F.
One pound of steam at 212 degrees Fahrenheit contains 1150 BTUs of energy.
To raise the temperature of 1 pound of water by 1 degree Fahrenheit, it requires 1 BTU (British Thermal Unit). Therefore, to heat water by 10 degrees, it would require 10 BTUs per pound of water. This value may vary slightly depending on the specific heat capacity of the water.
One BTU is the energy required to raise one pound of water by one degrees. Therefore, your answer would be one half.
There are no BTUs in an office water-cooler. But you can calculate how many BTUs are removed by the cooler. One BTU or British Thermal Unit is the amount of heat energy required to raise the temperature of one pound of water one degree Fahrenheit. There for when you remove one BTU you are lowering one pound of water one degree Fahrenheit. So if you know how many pounds of water you have and the temperature of the water you start with and the temperature of the water comming out of the cooler you can calculate how many BTUs the cooling unit of the water cooler has removed. BTU=Temp1 - Temp 2 X LB water
One million.
There are approximately 6,700-8,300 BTUs per pound of lignite coal. A ton of lignite coal contains 20-24 million BTUs.
To change 10 pounds of ice at 20 degrees Fahrenheit to steam at 220 degrees Fahrenheit, you need to supply enough energy to first melt the ice, then heat the water to the boiling point, and finally convert it to steam. This process requires approximately 180 BTUs per pound of ice to melt it, 180 BTUs per pound of water to heat it to the boiling point, and then 970 BTUs per pound of water to convert it to steam. So, for 10 pounds of ice, the total BTUs required would be around 18,300 BTUs.
212 - 80 = 132 degrees temperature increase x 1 pound water = 132 BTU