Direct gas heat has become the most common heat source in pallet kilns. Reasons why direct gas heating is the most common for pallet kilns:
- Pallet kilns require a lot of heat in a relatively short time period (2-4 hours)
- Direct gas heating offers more heat capacity for the lowest price.
- Direct gas heat wastes no energy (all combustion heat stays in chamber).
- Indirect heat will normally loose 15-25% of the energy through the chimney.
- Lower natural gas prices have made direct gas heat even more competitive to all other heat sources.
- The safety concern of direct gas heat has been proven unfounded when well designed with the right safety systems.
When does in-direct heat make sense?
- When the fuel source is significantly lower than your gas heating costs.
- When the HT or Drying process is longer so it can pay for the higher investment of in-direct heat.
- When capacity is available to supplement or replace gas heating.
How does Kiln-direct pallet kilns take these factors into account and in anticipation of more pallet drying (= longer cycles) and therefore in-direct heat from wood waste may become economical.
- All our standard pallet kiln designs (not container based) can be upgraded with hot water or steam coils.
- All our standard pallet kiln can be setup with dual heat source to supplement the gas heat.
- Controls activate different heat system at different temperature ranges where these are most efficient.
Kiln-direct believes that for lower volume drying pallets and even high volume pallet heat treating that Direct gas will still be the preferred choice for most. But in cases where large amounts of pallet drying is done then in-direct heat from wood waste would make more and more economic sense. In addition, for pallet companies that have wood waste heating for their plant it would also make sense to divert hot water or steam to the kiln for supplemental heat to reduce gas costs.