Resources, Tools and Basic Information for Engineering and Design of Technical Applications!
mobile - visible on handheld devices - alternatively go to www.engineeringtoolbox.com!
Engineering ToolBox > Fuel Oil and Combustion Values
Heating or combustion value of a fuel can be expressed as the quantity of heat (Btu per gallon) released during the combustion process where oxygen reacts with hydrogen and carbon.
The combustion or heating value for some common fuels oil grades can be found in the table below:
| Grade | Heating Value Btu/gal | Comments |
| Fuel Oil No. 1 | 132,900 - 137,000 | Small Space Heaters |
| Fuel Oil No. 2 | 137,000 - 141,800 | Residential Heating |
| Fuel Oil No. 4 | 143,100 - 148,100 | Industrial Burners |
| Fuel Oil No. 5 (Light) | 146,800 - 150,000 | Preheating in General Required |
| Fuel Oil No.5 (Heavy) | 149,400 - 152,000 | Heating Required |
| Fuel Oil No. 6 | 151,300 - 155,900 | Bunker C |
No. 1 and No. 2 fuel are both used for residential heating purposes. The No. 2 is slightly more expensive but the fuel gives more heat per gallon used.
The No. 1 fuel oil is used in vaporizing pot-type burners. The No. 2 is used in atomizing gun-type and rotary fuel oil burners.
The heavier the grade of fuel used in an oil burner, the greater the care must be taken to ensure that oil is supplied the combustion process at the proper atomizing temperature. With to low temperature the fuel oil will not atomize and evaporate as it should and the burner will not operate efficiently.