Drying and machining
John Fairweather Specialty Timber Solutions produces hardwood timber products from eucalyptus trees grown in Canterbury.
Using locally-grown hardwoods creates jobs and contributes to the Canterbury economy.
• Timber is air dried to less than 20% moisture content before kiln drying
• Solar Rola MiniPro solar kiln imported from Australia
• Solar kiln made from US design by Jim Birkemeier, TimberGreen Farm, Wisconsin
• Logosol PH260 Planer Moulder imported from Sweden.
Drying with solar kilns
How do they work?
• Solar kilns capture heat from the sun and use this to heat air
• Air is moved by modest fan pressure through stacks of timber in the kiln chamber
• The air is recirculated back to the solar collector
• There is a cyclic pattern of heating – the timber is heated by day and then cools down at night
• Cyclic drying allows the surface and the core of the timber to keep in equilibrium
• No steam reconditioning is necessary
• The resulting timber is very stable.
Solar kilns have a modest capital cost but a very low running cost.