In the world of books and comic books, where words and images are the bridge between imagination and reality, a formidable villain lurks in the shadows: humidity. When left uncontrolled, this invisible threat can lead to:

  • Mould and mildew growth: High humidity creates a conducive environment for mould and mildew growth, leading to unsightly spots, discolouration, and unpleasant odours on book pages.
  • Paper deterioration: Excessive moisture can cause paper to become weak, brittle, and prone to tearing. This deterioration is accelerated by the swelling and shrinking of paper fibres as they absorb and release moisture.
  • Warped and curled pages: Fluctuations in humidity can cause pages to warp, curl, or become wavy, distorting the book's appearance and potentially making it difficult to read.
  • Ink bleeding and smudging: Moisture can cause the ink on pages to bleed, smudge, or transfer onto adjacent pages, compromising text and images as well as legibility.
  • Binding complications: High humidity can weaken adhesives and binding materials, leading to loosened or detached pages, covers, and spines.

Luckily, there is a superhero ready and equipped to fight the detrimental effects of excessive humidity: adsorption dehumidification. Controlling humidity within the recommended range of 30% to 50% RH is crucial for preserving books and other paper-based products. Implementing the right dehumidification strategy and maintaining optimal humidity levels will mitigate the risks of humidity-related damage.

The advantages of installing an adsorption dehumidifier in your bookstore to protect books and comic books against humidity include:

 Technical BENEFITS:
  • Preservation of books: Paper is sensitive to fluctuations in humidity levels. Excess humidity can lead to mould, mildew, and degradation of paper, which damages the quality and readability of your books. Optimal humidity levels, usually between 30% and 50%, will protect your valuable collection.
  • Consistent climate control: Maintaining consistent and controlled humidity levels even in varying ambient conditions. Indoor climate stability is crucial for preventing sudden changes in humidity that would lead to the warping and curling of pages.
  • Precise humidity regulation: Adsorption dehumidifiers maintain specific humidity levels, ensuring that the indoor climate stays within the recommended humidity range for preserving books. Unlike condensation dehumidifiers, adsorption units work effectively even in lower temperatures, which is especially important in a climate-controlled bookstore.
Business benefits:
  • Book quality and customer satisfaction: By protecting books against humidity-related damage, you can offer your customers books that are in the best possible condition. This improves customer satisfaction creating customer loyalty (repeat purchases) and positive reviews.
  • Reduced maintenance and replacement costs: Consistent humidity control reduces the need for costly maintenance, repairs, and product replacement, creating cost savings in the long run.
  • Brand reputation: A bookstore that demonstrates commitment to preserving the quality of its books fosters a positive reputation as a business that values its inventory and offers a superior shopping experience. This type of reputation attracts discerning customers and collectors.
  • Long-term investment: Installing an adsorption dehumidifier is an investment in the long-term preservation of the book inventory. This investment will pay off over time as the store can continue to offer high-quality books, without worrying about deterioration due to humidity.
  • Environment for special collections: If the bookstore deals with rare or antique books, having a controlled humidity environment is even more critical. An adsorption dehumidifier can create the ideal conditions for storing valuable and delicate collections, attracting serious collectors and enthusiasts.
  • Compliance with industry standards: Some regulations or standards may require proper climate control for preserving books, especially if the store intends to collaborate with libraries, educational institutions, archives, or other similar organisations.


The owner of a book and comic book store in Belgium, De Poort, reached out to Cotes Partner, CTS BeNeLux, for a solution to persistent high humidity levels in the basement, which was intended for storage of rare comics and books.

The client's basement had consistently high humidity levels ranging from 70% to 85% relative humidity (RH). Recognising the potential damage that excessive humidity could cause to the rare and valuable collection, the client sought a reliable solution for creating an environment that would be conducive to preserving and protecting their books and comics.

Upon assessment, it was discovered that another firm had previously installed a house ventilation system that merely circulated air from outside into the basement, and which failed to effectively reduce humidity levels. Despite this effort, the RH remained above 55%, well beyond the optimal range for book preservation.

The hero of our story: CR400B adsorption dehumidifier

CTS BeNeLux removed the ineffective ventilation system and installed a tailored adsorption dehumidifier setup. A CR400B adsorption dehumidifier was strategically placed to optimise air circulation, and a regeneration line was established to vent the moisture-laden air outside through a sewer cover. To prevent potential condensation from forming on the basement's exterior, a condensation drain was also installed.

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Images: A Cotes CR400B dehumidifier installed in the basement of De Poort comic and book store

Measurements taken soon after the dehumidifier was installed showed a significant improvement in air quality. The client immediately recognised the vast improvement and expressed satisfaction with the project's outcome. The RH levels in the basement swiftly dropped to within the desired range, creating an ideal environment for storing and protecting the client's rare comics and books.

The positive impact of the dehumidification project extended beyond improved air quality. The ability to maintain controlled humidity levels now allows the client to store their valuable comic book collections securely. Cotes dry-air solution combined with our partner CTS BeNeLux' excellent customer service resulted in great customer satisfaction. The client immediately requested an annual maintenance contract with CTS BeNeLux.

"I am very satisfied with the speed of delivery, installation, and commissioning. I have tried other ways to protect the books before, but Cotes adsorption solution is the only one that works effectively and well." - Kurt Vander Meeren, owner of De Poort


OI_Comic-Book-Store-with-CTS-BeNeLux_4_resized_06092023Image: Ducting installed on the ceiling of the basement

Dedicated to sustainability

The project at De Poort is a great example of how strong partnerships can make a difference in working for the green energy transition. The entire De Poort bookstore, including the Cotes CR400B unit, runs on energy obtained from solar panels. During the day, the solar panels generate more electricity than needed, which is then stored in a 15kW battery, which covers nighttime consumption. By storing the surplus electricity that is generated during the day, the bookstore prevents electricity from going to waste. This is both an operationally efficient solution saving electricity costs, and an environmentally-friendly way of contributing to the green energy transition.

In the dynamic realm of sustainability, we face challenges that demand more action and greater accountability. At Cotes, we understand the importance of committing to a better future for people, businesses, and the planet. Effective partnerships are essential – our sustainability strategy thrives on collaboration and shared action. This example of collaboration of Cotes’ adsorption dehumidifiers, which can be powered by renewable energy, with the shared commitment to sustainability of our partner and end-customer, demonstrates the significant impact that effective teamwork can have on advancing environmental goals.

Leading by example is one of our core principles, and we are proud that sustainability is a value that we share with our trusted partners as well as our end customers.










The size of the space and the amount of humidity you need to remove from inside a particular storage area are usually the biggest determinants of which Cotes dehumidifier will best suit your particular needs. 

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Image: Cotes modular and mobile dehumidifiers 

Cotes mobile units consist of a selection of compact, lightweight dehumidifiers, built for mobility, with a handle for easy lifting and transportation, ideal for temporary storage setups and special exhibitions as well as other ad hoc humidity control requirements. Learn more about the range of Cotes Mobile dehumidifiers here: Download Cotes Mobile Dehumidifiers Datasheet.


Do you have issues with humidity?

If you would like to determine the right dry-air solution for your production or if you would like to explore what a custom dry-air strategy could do for your business, please reach out to one of our trusted partners near you.

Find a Cotes Partner near you