Wood Chip Fuel Calculator

Water in wood chips both dilutes the burnable wood fiber per pound and absorbs combustion energy as latent heat while evaporating, so wetter chips deliver fewer usable BTU per pound than drier ones. To supply the same total heating energy, the calculator needs a larger weight of wetter chips to make up for their lower energy density -- this is why Chip Moisture moves both Chip Weight and Chip Volume upward as it rises.

Boiler Efficiency describes how much of the fuel's raw energy content actually becomes useful heat versus being lost up the stack or through incomplete combustion. A less efficient boiler needs more total fuel energy input -- and therefore more chip weight -- to deliver the same net heating output, so lowering efficiency raises both Chip Weight and Chip Volume for a fixed Heating Need.

Wetter chips are typically cheaper per ton to purchase than seasoned, air-dried chips, since less processing (time, handling, storage) went into producing them, so the calculator's cost-per-ton figure decreases slightly as moisture rises even while the total tonnage needed increases -- the two effects partially offset but don't cancel, since weight increases faster than the per-ton discount.

Freshly chipped "green" wood typically runs 40-55% moisture on a wet basis, while chips that have been air-dried or stored under cover for several months typically drop to 20-30%. This calculator's Chip Moisture input covers 10-60%, spanning both cases, and the difference between them meaningfully changes both the tonnage and cost estimates for the same heating requirement.