Viljandi Aken ja Uks, a manufacturing company in Viljandi, employs 700 people. It is one of the largest door and window manufacturers in the Baltics and the largest employer in Viljandi. The group's companies have an annual turnover of nearly €100 million and a total annual production capacity of 700,000 units. However, processing large volumes brings challenges in handling airborne chemicals. Production must comply with environmental requirements and must not cause pollution in excess of permitted levels. With ever-increasing production volumes, this is also an ever-increasing challenge, which the Viljandi timber producer found a solution to in cooperation with Elister OÜ, a company providing industrial finishing solutions. 

The company introduced an automatic activated carbon filter in both the coating and drying process, which absorbs harmful compounds that volatilize into the air and purified air comes out of the filter. It is a ventilation solution with two charcoal filters, one of which is always in operation and the other is waiting to be reactivated when the coal is reactivated. This makes it possible to increase production capacity while keeping the air around the coal clean.

Finishing materials containing volatile organic compounds (paints, primers, solvents, stains, etc.) are used in wood finishing and may be harmful to the ambient air quality, in addition to causing odours. "In order to reduce the environmental impact, we started by improving the dispersion conditions in the production first and looked for alternatives to the chemicals used, taking into account the quality of the final product," shared Veiko Põldsaar, head of development projects at Viljandi Aken ja Uks. He added that, as the company is an emerging industry and the VOC reduction method is effective, the options remain limited, which would hinder the company's development and increase production. Therefore, it was decided to implement an exhaust gas purification system in addition to the existing one, for which a coal filter was chosen. "In coordination with the Environmental Protection Agency, Viljandi Akna and Uks has a VOC reduction action plan, which foresees the introduction of a carbon filter to capture VOCs in the exhaust gases and thereby limit air pollution,". shared the environmental action plan of the Viljandi timber company's development project manager.

"The solution for the automatic coal filter comes from MIAB, a Swedish manufacturer with long manufacturing experience," notes Indrek Ester, who led the project for Elister OÜ. "The activated carbon taps installed in the ventilation system absorb the necessary compounds, achieving an air purity of at least 85%. In testing, a purity of as much as 99.8% was achieved.

The reliability of the system is ensured by the use of 2 filtering devices operating in parallel, ensuring that when one filter fills up, the other automatically switches on. During the activation process, cleaning takes place and the same charcoal is reusable after activation", explained Ester. "Similar technology is quite new in Estonia and is used in only 2 companies, but we see that with increasing production volumes and from the point of view of promoting green production, it could be suitable for a number of manufacturing companies," said Elister's representative, who said that a ventilation system with a charcoal filter could be used by companies using liquid paints, solvents and similar finishing products.  

"At Viljandi Aken ja Uks, we installed a fully automatic filter with remote control and other benefits, but a smaller company can use a filter with manual charcoal exchange on a similar principle. If the production volumes are small and the budget does not allow for a fully automatic system, this is also a good and suitable solution," says Elister's representative, pointing out a variant of the charcoal filter that would help small companies in particular to remain environmentally compliant.

Increasingly, the challenge for industrial companies is to find a balance between investment in developing production and investment in the environment. In both cases, this is a necessary and unavoidable step for the future, especially if the industry is located in a residential area. In the case of the Viljandi Windows and Doors project, it is a carefully considered combination where the solution supports both the environmental and the business development aspects. 

"The use of a ventilation system with a carbon filter will help production plants to reduce odour nuisance in the surrounding area and help to keep outdoor air pollution levels under control and at the levels required by law. In an industrial sector that is constantly moving towards automation, a similar solution is certainly a necessary and reliable solution," said Indrek Ester of Elister OÜ.