VOLUME/WEIGHT/ENERGY RATIO CALCULATOR Instructions
t
t
Solid m3
Bulk m3
Stacked m3
GJ
MWh
l
t
l
The units of weight used for wood fuels are the kilogram and the metric ton. It will always be stated whether the weight refers to dry or fresh tone/kilogram of fuelwood and whether the mass of moisture in the material is included or not.
Cut and split oven-ready fuelwood used in household wood burning appliances like stoves, fireplaces and central heating systems.Firewood usually has a uniform length, typically in the range of 150 mm to 1000 mm.
Chipped woody biomass in the form of pieces with a defined particle size produced by mechanical treatment with sharp tools such as knives. Wood chips have a subrectangular shape with a typical length 5 mm to 50 mm and a low thickness compared to other dimensions.
For practical use in fuelwood sector following definitions can be used:
Solid cubic metre (scm – m3) is the unit of measurement for a cubic metre of solid wood without air gaps. This unit of measurement is commonly used for timber – round wood.
Stacked cubic metre (stcm - stacked m3) is the unit of measurement for stacked wood that attains a total volume of one cubic metre including air gaps. Is the unit of measurement used for neatly-stacked log woods.
Bulk cubic metre (bcm - bulk (loos) m3) is the unit of measurement for small pieces of loose wood (e.g. wood chips, sawdust, wood pieces) that attain a total volume of one cubic metre including air gaps. Unit of measurement used for log woods and, more typically, wood chips.
It will always be stated whether the volume refers to the bulk volume, or the stacked volume of the material and whether the mass of moisture in the material is included. It depends on size and shape of particles, on their homogeneity and distribution.
Net calorific value (Hi) calculated value of the specific energy of combustion for unit mass of a fuel burned in oxygen at constant pressure under such conditions that all the water of the reaction products remain as water vapour (at 0,1 MPa) and the other products being as for the gross calorific value, all at the reference. When not specified, ‘calorific value’ is to be intended as net calorific value.
How to use the calculator
The calculator gives you preliminary calculation of different units (bulk, mass energy). Fort his calculation different factors are used. It is not necessary that this calculation always represent real situation.
Results have informative nature and authors will not be responsible for use or miss use of results.
Recommended steps for using this calculator:
Choose tree species
Choose water content (see section definitions – water content)
Write one of the units – number can be written in any of available fields (number written can be a whole number or a number with decimal number)
Calculator was developed by Department of forest technique and economics at Slovenian Forestry Institute.