Ongoing projects

Valutec's development efforts in lumber drying is our way of contributing to the foundation for growing numbers of people discovering the possibilities of wood as a construction material. Based on our vision of greater wood use, our development continues to result in innovative solutions that drive our industry forward.

Air velocity and temperature readings in TC continuous kilns

The rapid drying speed in TC continuous kilns means that sensor location and the measurement of air values are especially important. To improve our simulators by also providing full support for TC continuous kilns, we measure air and temperature data in detail as the basis for calculating precise final moisture content. The readings were taken at Norra Skogsägarna in Kåge, Sweden, to describe the climate conditions in the different zones at various fan speeds and temperature drops. 

Valusim 4.0

The best of help with controlling the drying process is essential from many perspectives. Valusim 4.0 will allow us to simulate all kiln types, and operators will be able to select the control method they feel confident in, and which corresponds to their kiln equipment. It must be possible to control the process with or without a simulator link, fixed schedules or the previous schedule library.

New guidelines for the preheating phase

In effect, the ability to preheat specific lumber dimensions varies between different types of lumber kilns. For example, TC models are sometimes used without spraying/steaming, which works well on thinner dimensions with a high input moisture content. For coarser dimensions, the lumber can be preheated and controlled by means of a psychrometer. Preheating tests have been carried out with closed dampers in several zones so that the moisture laden air condenses on the new infeed cart as in other types of continuous kilns. This is also energy efficient, as it takes place without spraying/steaming or heat from the heater coils. Tests also show good results from heating lumber with higher psychrometer readings than standard values in batch kilns. The aim is to produce clear guidelines for preheating techniques in all types of lumber kilns with regard to capacity and quality.

Automatic control adaptation in continuous kilns

An earlier project that involved weighing lumber packages in green sorting before batch kiln drying, provided extremely good results in target moisture content accuracy. Valutec has advanced this by developing a model in which continuous kilns are able to change their setpoint values automatically during the process. In continuous kilns, variations in lumber dimensions and raw moisture content have been difficult to calculate, which has led to a focus on measuring temperature drop and psychrometer readings when the lumber packages are passing out of the zones. The basis is existing temperature and drying time setpoint values, where average value control and psychrometer readings are used for fine adjustment and managing lumber variations.

Weighing of packages for greater accuracy in the target moisture content

In collaboration with SP, TCN, Datapolarna, Bergkvist and Norra Kåge, Valutec is conducting a project where the weight of raw timber packages is used as input data to increase the accuracy of the target moisture content. A starting point is that the raw weight provides the current input moisture ratio for the calculation of the optimized drying procedure. This can provide valuable input data that improves both Valmatics and Valusim.

Thermal energy and air velocity in continuous kilns

This development project aims to ensure that added thermal energy with regard to air velocity is utilized as efficiently as possible in continuous kilns. The project aims to both identify strengths in existing designs, sources of leaks and future dimensioning and troubleshooting.


Valutec's simulator technology ValuSim is based on leading Swedish and Finnish expertise and development is conducted in cooperation with the Nordic region's leading wood researchers. ValuSim is based on a mathematical model that builds on numerical calculation of the wood material's internal moisture flow, shrinkage and drying stress. Simulated stress is used to calculate surface cracks using an extensive experimental material. In a user friendly interface, information is entered on the desired end quality together with known basic data. With this as a basis, a process that is very close to reality is simulated.


Valmatics is an adaptive control system that provides the kiln operator the maximum freedom of choice. The system can control most types and makes of air exchange systems for drying. A graphic and intuitively designed interface makes the system very easy to use. The integrated expert system with fact collections on quality parameters generates suggestions on how the drying should be carried out to optimize the process for the drying batch. Critical functions, including the technology to measure temperatures at the actual source and the simulation program, are protected by patents.

Fan speed optimization

Valutec's system for adaptive control of the fan speed enables effective and cost-saving electrical optimization. The method builds on the timber, based on the temperature drop over the timber load, telling the fan what speed is needed. When the timber has reached the fiber saturation point, a frequency converter adaptively turns down the fan's frequency because high air speed is no longer needed. The continued drying process is then regulated using the kiln's temperature.

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