BTUs - What do they mean to you, and how many BTUs does your gas appliance need?

The rule of thumb is this. Given a room with adequate insulation and typical ceilings (8 feet +/- 1 foot), each 10,000 Btu's of heat output from an efficient gas appliance will heat approximately 350 sq. ft. If the area to be heated has pitched or vaulted ceilings, poor insulation, or drastic air movement then the heating ability will be reduced. (Vented gas logs are not to be considered in this calculation as they are designed for appearance only.)

If your intention is to just take the chill off, then you may not need as much output as needed for a normal living space. Contact us with your needs, and we can make recommendations

Physical units reflect measures of distances, areas, volumes, heights, weights, mass, force, impulse and energy. Different types of energy are measured by different physical units: barrels or gallons for petroleum; cubic feet for natural gas; tons for coal; kilowatt-hours for electricity. To compare different fuels, we need to convert the measurements to the same units. Some popular units for comparing energy include: Btu, barrels of oil equivalents, metric tons of oil equivalents, metric tons of coal equivalents. In the United States, the British Thermal Unit (Btu), a measure of heat energy, is the most commonly used unit for comparing fuels. Since energy used in different countries comes from different places, the Btu content of fuels varies slightly from country to country. The Btu content provided below and used in the energy calculator reflect the average energy contents for fuels consumed in the United States.

What Is a Btu?

A "British thermal unit" (Btu) is a measure of the heat content of fuels. It is the quantity of heat required to raise the temperature of 1 pound of liquid water by 1°F at the temperature that water has its greatest density (approximately 39°F).

Why Do We Use Btu?

One practical way to compare different fuels is to convert physical units of measure (such as weight or volume) into a common unit of measurement based on the energy content of each fuel.The British thermal unit (Btu) is a widely used measure of energy content.

Using Btu for Comparing Home Heating Fuels

How can you compare home heating fuel prices? You must compare the cost per heating value (Btu) of each fuel. See How do I compare heating fuels? for a fuel conversion calculator.

Using Btu for Comparing Electricity Generation Fuels

Suppose you have been assigned the responsibility of purchasing fuel for a large electric utility company. You need to keep costs down for you and your electricity customers. Which fuel would you choose to generate electricity — coal, oil, or natural gas? In 2007, average prices of fuel delivered to electric power plants were:

• $35.48 per short ton of coal
• $43.50 per 42-gallon barrel of oil
• $7.31 per thousand cubic feet of natural gas
  

The prices of each fuel look quite different, but you can compare the prices of their energy content by first converting to Btu.

A short ton of coal contains about 21 million Btu, a barrel of oil contains about 6 million Btu, and a thousand cubic feet (Tcf) of natural gas contains about 1 million Btu. After dividing price by energy content, you can see which fuel is least expensive:

So coal is actually the least expensive fuel on a price-per-energy content basis.

Of course, cost is not the only factor to consider when selecting a fuel. Environmental restrictions and equipment costs are some of the other factors that should be taken into account.

Btu Quick Facts

A single Btu is insignificant in terms of the energy use in a single household or in the Nation's energy consumption. In 2008, the United States used over 99 quadrillion (written out, 1 quadrillion is a 1 followed by 15 zeros) Btu of energy.

One quadrillion Btu is a very large amount of energy:

• One Btu is approximately equal to the energy released in the burning of a wood match.
• One million Btu equals about 8 gallons of motor gasoline.
• One billion Btu equals all the electricity that 300 households consume in one month.
• One trillion Btu is equal to 500 100-ton railroad cars of coal.
• One quadrillion Btu is equal to 172 million barrels of crude oil.