Optimization Solar Energy for Timber & Wood Sector
Lumber that comes straight from felled trees cannot be used for anything related to timber products or building materials due to its high moisture content. Taking into consideration that it can take up to a year to dry a piece of lumber per inch of thickness, drying the lumber becomes one of the most important steps before doing anything. Instead of waiting several months, advancements in wood drying technology have reduced the time it takes.
Use of kilns is the ultimate option to draw moisture out of the wood in order to make it workable while minimizing the wood losses and improving the quality of the end products. It is also an effective way of ridding timbers of mold and insect infestation. This process of drying happens in a chamber/oven called a “kiln” in which time, steam levels, relative moisture and temperature can be controlled. Conventional methods demand a substantial amount of heat energy as constant heating of air is needed. Reduction in heat consumption and electricity for drying of timer can be achieved by modifying the conventional drying process. Solar drying has been found an effective alternative to conventional drying methods. This is an extremely effective methodology for converting the suns energy into directly heating the kiln.
So let’s take a closer look at what Solar kiln dried wood is and what are its benefits for the lumber industry.
What are Solar Kilns
A kiln is a type of furnace or oven used to dry and bake materials such as clay and wood. You can manage the temperature, airflow, and humidity levels in a kiln, which results in higher-quality dry lumber. The most significant benefit of using a kiln is that it accelerates the drying process. As a result, most wood manufacturing plants employ this oven to reduce the moisture content of young lumber to the necessary level.
A Solar kiln capture the energy of the sun to provide the heat energy required for the evaporation of water. Electric-powered fans are commonly used in solar kilns to allow air to freely move through the wood. Solar kilns gained immense popularity in the mid-1970s, when energy prices started to rise. Because it relies on heat collected from the sun’s radiation, it offers numerous benefits over traditional pollution emitting conventional energy sources.
Why is Solar drying better than Conventional drying?
The energy required to evaporate the water in a conventional kiln is roughly 50 percent more. Most energy consumption in a conventional kiln is required for the following processes:
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- Moisture evaporation
- Heating the kiln and lumber
- Kiln ventilation
- Thermal losses
- Air leakage, and
- Air humidification
In many cases, higher reduction in energy consumption can be achieved by dehumidifier units, vent heat exchangers, and air drying. These strategies however, require considerably modifications to an existing commercial process.
Solar kilns is an environmentally friendly drying system that was developed and established in the timber sector and may be used in a variety of applications where product drying and dehydration are required. Because the solar kilns are lightweight and portable, they are easier to move and have lower initial expenses. Nearly all timber species, particularly hardwoods, respond well to the proprietary cyclic control method and prescriptions. This means you’ll get better outcomes from your heat-treated wood at a lower cost.
The Reasoning behind Solar Drying
Solar kilns are becoming increasingly popular for the wood sector that needs moisture-free wood for making furniture. Because they run on the sun’s free energy, they’re free to run except for the minor expense of power to run the fans. Solar kiln are based on greenhouse principle and offer an appropriate technology for drying wood in a controlled environment. Solar driers are technically feasible and economically viable.
It has been claimed from numerous studies around the world that some benefits of the solar kiln include:
- Solar-drying kilns are the simplest, cheapest, and safest way to dry green wood quickly.
- Solar wood drying kilns are low cost alternatives for drying of timber produce especially in medium and small scale industrial set-ups.
- Solar kiln is relatively simple to construct, operate and maintain.
- It is a cost-effective and technology for wood drying.
- Just as fast, and in some cases faster than conventional drying technology.
- Solar kilns are not only less expensive and produce higher-quality heat-treated wood, but they also consume up to 90% less fossil fuel in the drying process.
- They are designed to keep the wood from drying too rapidly.
- It requires much less time and allows the wood to contract without warping.
- It automatically kills any insects, sanitizes the lumber from any kind of fungus or even eggs.
- A solar kiln can dry wood of various forms, sizes, or mixed species and thicknesses in the same load. While the wood dries, only minor vent adjustments are required after the kiln is loaded.
- A solar kiln can dry wood of various forms, sizes, or mixed species and thicknesses in the same load. While the wood dries, only minor vent adjustments are required after the kiln is loaded.
- Solar kilns can reduce the warping, cracking, and splitting of heat-treated wood by up to 98 percent.
- In comparison to conventional steam heated kilns, the cost of construction of the solar kiln is relatively much lower.
- Most importantly, they are good for the environment since they don’t generate CO² emissions.
Closing Thoughts
Solar-heated kilns have a lot of potential in underdeveloped countries, especially in isolated areas where traditional energy sources are scarce. Given the numerous benefits of solar kilns, more and more lumber mills and manufacturers have begun investing in accurate wood moisture content management tools and systems. With this trend continuing to grow it’s only a matter of time when most furniture makers will only use solar-kiln-dried wood for furniture making.