Types of Kilns

Wood drying is an essential process that is necessary for any woodworker or lumber producer. It is essential to ensure that the wood is dried properly to avoid issues such as warping, cracking, and decay. There are different types of wood drying kilns available, each with its unique advantages and disadvantages.

Solar Kilns

Solar kilns use the sun's energy to dry wood. These kilns are typically simple, low-cost, and environmentally friendly. The wood is stacked in a chamber with a transparent roof, which allows the sun's energy to enter and heat up the wood. A vent at the top of the kiln allows for ventilation, which helps remove moisture from the wood. Solar kilns work best in sunny climates and are not well-suited for large-scale operations. However, they are an excellent option for small-scale sawmills and woodworkers who want to dry lumber without the cost of traditional kilns.  They do dry at a slower rate compared to other types of kilns, but this does result in very high-quality lumber.

Dehumidification Kilns

Dehumidification kilns use refrigeration or desiccant systems to remove moisture from the air inside the kiln. These kilns are typically more expensive to operate than solar kilns, but they can be used in any climate. Dehumidification kilns work by cooling the air inside the kiln, which causes moisture to condense and collect on the cooling coils. The dry air is then recirculated back into the kiln. Dehumidification kilns are an excellent option for small to medium-sized operations that require precise control over the drying process.

Conventional Kilns

Conventional kilns use a heat source, such as gas or wood, to heat the air inside the kiln. These kilns are the most expensive type of kiln to operate, but they can dry wood quickly and can be used in any climate. Conventional kilns work by heating the air inside the kiln, which causes moisture to evaporate from the wood. The warm, moist air is then vented out of the kiln, and fresh, dry air is brought in to continue the drying process. The fast drying process can sometimes result in uneven drying, which can sometimes cause warping or cracking. Conventional kilns are an excellent option for large-scale lumber operations that require high volumes of wood to be dried quickly.

Vacuum Kilns

Vacuum kilns remove moisture from the wood by creating a vacuum inside the kiln, which lowers the boiling point of water and causes the moisture in the wood to evaporate more quickly. The steam is then removed from the kiln using a vacuum pump. These kilns are faster than conventional kilns and can produce higher-quality lumber because there is less possibility for warping or cracking. Vacuum kilns are very expensive but are an excellent option for high-quality lumber operations that require a quick turnaround.

Radio Frequency Kilns

Radio frequency kilns use high-frequency electrical energy to heat the wood from the inside out. These kilns are very fast and can produce high-quality lumber, but they are also expensive to operate. Radio frequency kilns work by using an electromagnetic field to heat the wood. The electromagnetic waves cause the water molecules in the wood to vibrate, generating heat and causing the water to evaporate. They use less energy than conventional kilns, which makes them more environmentally friendly. Radio frequency kilns are an excellent option for high-quality lumber operations that require a quick turnaround and can afford the high operating costs.

In conclusion, choosing the right type of wood drying kiln depends on several factors, including the volume of wood being dried, the desired drying speed, and the available budget for equipment and operating costs. Each type of kiln has its advantages and disadvantages, but here at Wildfire Lumber, we chose to go with a solar kiln because it is the most earth-friendly option, and it preserves the natural colors and characteristics of the wood better than any other type.