Summary
• Reducing energy consumption is a growing part of the market.
• International manufacturers are focusing their attention on developing markets.
• The market for ThermoWood kilns is growing by 30% each year.

Traditionally kilning has been energy greedy, but with green issues now at the top of the timber industry’s agenda worldwide, it’s no surprise that kiln manufacturers are firmly focused on improving their environmental performance.

Kurt Mühlböck, managing director of Austrian firm Mühlböck, said that the use of energy within kilns was an inevitable talking point for customers and that manufacturers needed to respond.

“Rising energy prices and even more flexible and more economical drying procedures are facts which cannot be ignored,” said Mr Mühlböck. “We are already offering our customers drying kilns which can be adapted to the changing future requirements and guarantee economies.”

The company has launched two models as part of its answer to the conundrum, which it describes as a “milestone in timber drying”. The 603 and 606 models both offer drying time reductions of up to 50%, thermal savings of 30% and a reduction in energy consumption of around 80%.

Heat recovery system

Meanwhile, Kiln Services Ltd, from Essex, has been working on a heat recovery system for kilns, which managing director John Commons describes an “exciting development”.

“A great deal of time and money has been devoted to this project, which is now producing excellent results,” he said. “We have transferred 104kW of heat energy per hour from the hot moisture-laden air into the fresh dry air entering the kiln, raising the temperature from 10ºC to 67ºC of 7,000m³ of air per hour.

“This is the equivalent of saving 9.6 litres of oil per hour during kiln venting. Even for companies with wood waste boilers, or combined heat and power plants, a great deal of extra power can be fed into the National Grid instead of venting to atmosphere.

“The heat recovery system has enabled kilns to carry out venting with no drop in air temperature which in turn has reduced average drying times by 15%, also saving electrical consumption on air circulating fans. The system will produce a new generation of heat vent kilns, which will be 25-30% more efficient.”

Mr Commons added that Kiln Services has been busy working on other environmentally-sensitive projects, including high temperature models for the production of firewood and other timber-based fuels.

“Over the last year, we have received several enquiries for drying mixed hardwood logs for log-burning fires and stoves, and have developed a new range of high temperature kiln, with air temperature of over 100ºC,” said Mr Commons.

The first of these kilns has now been installed and commissioned in Ireland to dry hardwood logs. The first batch of 20 cages of product, each holding 1.4m³, were dried in 44 hours and turned 28m³ of logs into a “premium product”. The outside 20mm of depth had dried down to a moisture of 8%, with some element of case hardening, trapping a higher core moisture of around 25% in the centre of the log.

“The client is delighted with this result as it has produced a product that produces no condensation in storage within its packaging,” said Mr Commons. “It lights easily due to the low surface moisture, and has a reasonable burning time due to the higher core moisture. Also, due to the very high drying temperature, the product is sterilised with no bugs or insects.”

Microwave power

Romania’s Microunde Consulting Ltd has also been pushing its range of microwave-powered timber dryers, claiming that they need less energy to dry timbers, reduce drying times, increase production rates, generate bigger yields of higher grade products and reduce operating costs.

Kilns designed to produce specific energy-efficient, eco-friendly products are also growing in popularity, with Sweden’s Valutec AB reporting an increase in uptake of kilns capable of creating ThermoWood products.

“ThermoWood kilns are also a coming market,” said Robert Larsson, sales and research and development manager at Valutec. “We are seeing growth in the area of around 30% a year.”

The ThermoWood process creates very stable timber that has a lower carbon footprint through manufacturing and transport than concrete and steel, according to the Finnish ThermoWood Association. Its machining characteristics are also comparable to sawn timber and impregnated wood, it says.

Global demand

Driven by growing demand for kiln-dried wood in construction, plant health issues and now the improved environmental performance of their products, kiln demand is rising globally, according to manufacturers.

New equipment continues to be installed in the developed markets of western Europe, the Nordic countries and North America. SCA Timber for instance, has just invested £3m in a progressive facility at its Tunadal site in Sweden, with the capacity to handle around 100,000m³ a year. And Stora Enso has spent €5m on a ThermoWood kiln for its Bad St Lonhard site, which will increase its capacity to 30,000m³ a year.

But, while these markets continue to spend, manufacturers say the big kilning expansion is now taking place in eastern Europe. “Russia, Bulgaria and Romania are all growing markets,” said Andreas Ruf, sales manager at BES Bollman of Germany.

Roberto Bergemini, from Italian producer Nardi International, said France was a buoyant market for the company currently, but that Russia and eastern Europe are becoming increasingly important.

Mr Larsson said Valutec was also seeing more business in central Europe and developing markets and said this was also due to the company’s sales shift from compartment dryers to progressive models. “We used to manufacture 80% compartment kilns but now it is more like 80% progressive,” he said.

Strategic alliance

The increasingly global spread of business is prompting structural developments in the kilns sector too. New Zealand’s Windsor Engineering Group Ltd, for instance, has announced a strategic alliance with Germany’s Brunner Hildebrand. This will develop a “worldwide business model” for selling kilns and see the two firms share technical information and marketing, bringing together promotion for Brunner’s High-Vac systems and Windsor’s Dryspec kiln management system and DryTrack moisture measurement technology.

“The two companies, each with engineering, design and manufacturing facilities, are to a large extent complementary and seen as a sensible fit for a new business model worldwide,” said Keith Robertson, international business manager at Windsor.

Manufacturers agreed that the UK kilns market has been relatively flat: “It has been a very good for us for years but is now stabilising,” said Mr Ruf.

However, all the companies said they still had plans to develop their UK business. Windsor, for instance, has been focused on the Sitka spruce market, targeting its DryTrack system at UK timber processors. No sales had been secured yet, but the company is persisting. “Our experience is that it takes a few years to introduce different technology and break into new markets,” said Mr Robertson.

Meanwhile, BSW Timber’s £3.5m investment at its Newbridge-on-Wye site has included the installation of two batch chamber kilns from Bes Bollmann, alongside three existing models.