Solar Wood Drying Kiln

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The Himalayan Institute Cameroon’s School of Carpentry & Construction has finished building a new wood drying kiln. A wood kiln is an enclosed structure where heat and moisture are controlled in order to dry wood as fast as possible with the least amount of drying defects such as warping and cracking. This is the first wood drying kiln in Kumbo and will make a huge difference for the carpentry trade in the area.

In the past, carpenters from Kumbo have often been unable to afford properly dried wood, which is imported from the large city of Bamenda, located three hours away. The result is that many carpenters must work with uncured wood, which warps after a few months. Having dried wood locally available will make lumber more affordable and will improve the overall quality of carpentry projects in the region.

Fiberglass panels in the roof allow sunlight to passively heat the kiln interior. By utilizing solar thermal heating, the kiln can operate at a fraction of the cost of traditional kilns. A heavy-duty fan for moving air and controlling humidity was fashioned from the fan of an old Toyota truck–a great example of how a little ingenuity can create local solutions for local problems!

Check out pictures of the construction process:

More details about the kiln:

  • Local wood facts
    • Rough cut boards randomly stacked take two years to dry.
    • Rough cut boards properly stacked and covered take 6 months to dry.
    • Rough cut boards properly stacked in our new solar kiln are estimated to take 3 months to dry.
    • Normally, unseasoned wood harvested around Kumbo is sold to Bamenda, where it is dried, then sold back to Kumbo to those people who can afford seasoned wood.
    • Local carpenters are compelled to make furniture from green wood, thus furniture cracks and falls apart only a few months later. Despite the great deal of time and effort put into local projects, carpenters do not take much pride in their work and cannot make an adequate profit from their furniture since people will not pay much for short lived products.
  • What are the specs for our kiln?
    • 20 ft wide by 19 ft deep by 6.5 ft tall.
    • Capacity is around 1000 planks (or 1500 board feet in lumber trade talk).
    • We used locally available parts to construct the kiln:
      • The kiln’s circulation fans were salvaged from Toyota cars.
      • The kiln has a car battery backup power source in case of power failures.
      • The main structure was built with locally available building supplies. Eg. Metal sheets and Cyprus boards.
    • Kiln has a digital control panel with a built in hygrometer and thermometer to monitor humidity and temperature inside the kiln and record the highs and lows for the day.
  • Why build and use a wood kiln in Kumbo?
    • Increases the value of the wood. Seasoned wood fetches a higher price.
    • Seasoned wood makes long lasting furniture.
    • Seasoned wood allows a better finish to be applied.
    • Carpenters take more pride in their furniture since it will last and will be higher quality.
    • Carpenters make more profit since they can sell their furniture for a higher price.
  • What service does the wood kiln provide to HI Cameroon and the community?
    • The School of Carpentry & Construction has a consistent supply of well seasoned wood to build its world class furniture.
    • The seasoned wood is available for local carpenters to buy at a modest price, which generates income for HI Cameroon.
    • Increases pride in the community.
    • Carpenters can make more elaborate projects knowing they will last.
    • The community can see that progress isn’t leaving them behind.
    • The kiln is built in a simple way so that local enterprises can envision building their own kilns.
  • What is the future for the wood kiln?
    • Data will be collected to create the most efficient drying schedule for local woods. This knowledge can be passed on to the community.
    • An innovative sawdust burner has been envisioned as an upgrade for the future to augment rainy season drying times.
    • The kiln will also double as an herb dryer for our Total Health Center medicines.

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