What does the British thermal unit measure?
British thermal unit (BTU), a measure of the quantity of heat, defined since 1956 as approximately equal to 1,055 joules, or 252 gram calories. It was defined formerly as the amount of heat required to raise the temperature of one pound of water 1° F.
What are British units used for?
Imperial units, also called British Imperial System, units of measurement of the British Imperial System, the traditional system of weights and measures used officially in Great Britain from 1824 until the adoption of the metric system beginning in 1965. The United States Customary System of weights and measures is derived from the British Imperial System.
How many watts are in a BTU?
We know that each BTU is equal to 0.293 watts. Now, we have 10,000 BTU. Here’s how we use BTU to watt formula to calculate the capacity of a window air conditioner in watts: In short, 10,000 BTU is equal to 2,930 watts. Let’s confirm this with the conversion calculator:
What is BTU hr?
For some other common conversions, here's a helpful list from hometips.com :
- 1 BTU equals 252 to 253 calories
- 1 BTU equals .293071 watt-hours
- 1 watt is approximately 3.41214 BTU hours
- 1,000 BTU hours equal approximately 293.071 watts
- 1 therm equals 100,000 BTUs
- 1 "ton" of cooling equals 12,000 BTUs per hour
- 1 standard cubic foot of natural gas yields 1,030 BTUs
Why is it called British Thermal Unit?
It came from the mind of Thomas Tredgold, a British railroad engineer who dabbled in heating and ventilating public buildings. What's delightful about that definition, though, is the business about a cubic foot of water rising in temperature by one degree Fahrenheit.
Is the unit of heat in English system unit?
Generally, all forms of energy are measured in terms of joules in the SI system. Notably, heat is a form of energy, and therefore the SI unit of heat is also joules (J) which are defined as the amount of energy needed to raise the temperature of a given mass by one degree.
Is Btu a unit of energy?
British thermal units, or BTUs, are a unit of energy. It is the amount of energy required to heat a pound of water by one degree Fahrenheit at one atm.
What is metric British Thermal Unit?
British thermal unit (BTU), a measure of the quantity of heat, defined since 1956 as approximately equal to 1,055 joules, or 252 gram calories.
What is the unit for thermal energy?
JoulesThermal energy is measured in Joules, a SI unit of measurement (J).
What BTU means?
British Thermal UnitBTU is short for British Thermal Unit, a unit of measurement that shows just how much energy your air conditioner uses to remove heat from your home within an hour.
What are the 3 units of heat?
Other Heat Units:BTU.Calorie.Joules.
What is BTU vs joule?
The modern SI unit for heat energy is the joule (J); one BTU equals about 1055 J (varying within the range 1054–1060 J depending on the specific definition; see below). While units of heat are often supplanted by energy units in scientific work, they are still used in some fields.
What are the 2 units for heat?
The two units of heat most commonly used are the calorie and the British thermal unit (BTU).
What are the 3 units of heat?
Other Heat Units:BTU.Calorie.Joules.
Is Celsius a unit of heat?
The unit of measuring temperature is celsius, The Centigrade (Celsius) Scale: This scale has lower fixed point as the melting point of ice and upper fixed point as boiling point of water and between the two points is divided into 100 equal parts.
Is Joule a unit of heat?
The unit of quantity of heat is the joule (J). Heat flow may be expressed as joules per second (J/s), but as a heat flow of one joule per second equals one watt the unit watt (W) is usually adopted for practical purposes.
What is the British thermal unit?
The British thermal unit ( BTU or Btu) is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is also part of the United States customary units. Heat is now known to be equivalent to energy. The modern SI unit for heat and energy is the joule (J);
What is the unit of power for heating and cooling systems?
The SI unit of power for heating and cooling systems is the watt. Btu per hour (Btu/h) is sometimes used in North America, though "Btu/h" is sometimes abbreviated to just "Btu". MBH —thousands of Btus per hour—is also common.
What is the BTU of a thermochemical calorie?
Originally, the thermochemical BTU was defined as the heat required to raise the temperature of one pound of water from its freezing point to its boiling point, divided by the temperature difference (180°F). The basis for its modern definition in terms of SI units is the similar, thermochemical calorie, which was originally defined as the heat required to raise the temperature of one gram of water from freezing to boiling divided by the temperature difference in Celsius (100°C). The International Standards Organization now defines the thermochemical calorie as exactly 4.184 J. The thermochemical BTU is then defined using the conversions from grams to pounds and from Celsius to Fahrenheit.
How many BTUs are in a decatherm?
The unit therm is used to represent 100,000 BTUs. A decatherm is 10 therms or one MMBtu (million Btu). The unit quad is commonly used to represent one quadrillion (10 15) BTUs.
What is the temperature of a pound of water?
The centigrade heat unit (CHU) is the amount of heat required to raise the temperature of one pound of water by one Celsius degree. It is equal to 1.8 BTU or 1,899 joules. In 1974, this unit was "still sometimes used" in the United Kingdom as an alternative to BTU.
How many BTU per hour?
For one square foot of the insulation, one BTU per hour of heat flows across the insulator for each degree of temperature difference across it. 1 therm is defined in the United States and European Union as 100,000 Btu—but the U.S. uses the Btu 59 °F while the EU uses the Btu IT.
What is BTU in water?
A BTU was originally defined as the amount of heat required to raise the temperature of 1 avoirdupois pound of liquid water by 1 degree Fahrenheit at a constant pressure of one atmospheric unit. There are several different definitions of the BTU that are now known to differ slightly. This reflects the fact that the temperature change of a mass ...
Where does the term "therm" come from?
The therm sometimes has been confused with the thermie. The names of both units come from the Greek word for heat.
How much energy is in a therm?
The therm (symbol, thm) is a non- SI unit of heat energy equal to 100 000 British thermal units (Btu ). It is approximately the energy equivalent of burning 100 cubic feet (2.83 cubic metres) – often referred to as 1 CCF – of natural gas .
What is 10 therms?
10 therms are known as a decatherm (sometimes, dekatherm; commonly abbreviated Dth), which is 1 000 000 Btu (of whichever type). Further common abbreviations are MDth for a 1000 decatherms, and MMDth for 1 000 000 decatherms.
What is a therm factor?
Since natural gas meters measure volume and not energy content, a therm factor is used by natural gas companies to convert the volume of gas used to its heat equivalent, and thus calculate the actual energy use. The therm factor is usually expressed in units of therms per CCF. It will vary with the mix of hydrocarbons in the natural gas.
Which gas has a higher therm factor?
Natural gas with a higher than average concentration of ethane, propane or butane will have a higher therm factor. Impurities, such as carbon dioxide or nitrogen, lower the therm factor. The volume of the gas is calculated as if measured at standard temperature and pressure (STP).
How much carbon dioxide does a therm of natural gas produce?
According to the EPA burning one therm of natural gas produces on average 5.3 kg (11.7 lb) of carbon dioxide.
Overview
The British thermal unit (BTU or Btu) is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is also part of the United States customary units. The modern SI unit for heat energy is the joule (J); one BTU equals about 1055 J (varying within the range 1054–1060 J depending on the specific definition; see below).
Definitions
A BTU was originally defined as the amount of heat required to raise the temperature of 1 avoirdupois pound of liquid water by 1 degree Fahrenheit at a constant pressure of one atmospheric unit. There are several different definitions of the BTU that differ slightly. This reflects the fact that the temperature change of a mass of water due to the addition of a specific amount of heat (calculated in energy units, usually joules) depends slightly upon the water's initi…
Conversions
One Btu is approximately:
• 1.0551 kJ (kilojoules)
• 0.2931 W⋅h (watt hours)
• 252.2 cal (calories)
• 0.2522 kcal (kilocalories)
Associated units
• 1 ton of cooling, a common unit in North American refrigeration and air conditioning applications, is 12,000 Btu/h (3.52 kW). It is the rate of heat transfer needed to freeze 1 short ton (907 kg) of water into ice in 24 hours.
• In the United States and Canada, the R-value that describes the performance of thermal insulation is typically quoted in square foot degree Fahrenheit hours per British thermal unit (ft ⋅°F⋅h/Btu). For one square foot of the insulation, one BTU per hour of heat …
See also
• Conversion of units
• Latent heat
• Metrication
• Ton of refrigeration
External links
• "The Units of Measurement Regulations 1995". www.legislation.gov.uk. HMSO. 13 July 1995. Retrieved 23 February 2018.
• "Natural Gas: A Primer". www.nrcan.gc.ca. Natural Resources Canada. 27 November 2015. Archived from the original on 24 February 2018. Retrieved 23 February 2018.