Maintaining Document Integrity through Seasonal Humidity

Keeping your archives or stored documents in a temperature-controlled environment is a great first step toward protecting them from the harsh effects of the elements outdoors. If your area experiences seasonal changes or high humidity levels, an HVAC system might not be enough in regards to moisture and condensation control. Regardless of the environment in which you store documents—including files, books, photos and films—planning for seasonal humidity now helps prevent the need for mold remediation services in the future.

How Temperatures and Relative Humidity Levels Affect Documents

Documents like books, paper, linens, leather, film and canvas are hygroscopic, as they naturally absorb and release moisture to achieve a state of equilibrium with their environment. Depending on an area’s relative humidity level and temperature, the materials expand and contract, making them vulnerable to rapid deterioration and mold.

Warm air is more humid because it contains more water vapor. This is why it tends to feel muggy during the summer months. This added water vapor in the air affects the documents in your facility, which is why more offices experience printer and copier paper jams during the summer. In the winter, when conditions are drier, documents tend to desiccate and become more brittle.

Document Preservation and Condensation Control Tips

The environment in which you store documents is vital to their safekeeping. The best locations have the following characteristics:

• Relative humidity levels between 30 and 50 percent throughout the year, depending on the type of media
• Temperatures between 65°F and 70°F throughout the year; some types of media, such as film, might benefit from cooler temperatures
• Adequate ventilation
• Air filtration system
• No dust
• No carpeting
• Moisture detectors
• Tall ceilings with no overhead water pipes, other than a fire extinguishing system
• No sunlight
• Light levels between 5 lux and 165 lux, depending on the material’s sensitivity
• UV levels from lighting has a maximum of 75 microwatts of UV radiation per lumen of visible light (µW/l)
• Acid-free shelves and storage containers made of materials that don’t release harmful gases
• Water- and fireproof file cabinets

Unlike comfort systems, climate-control system settings in a document storage area should not change based on building occupancy. It is best to maintain constant temperatures and relative humidity levels 24 hours a day, every day of the year. While it might seem more expensive in regards to energy use to maintain constant conditions, the cost is considerably less than the expense of mold remediation services.

If the storage environment is cooler than the temperature in the rest of the facility, gradually acclimatize the materials that you take out. Otherwise, the radical temperature change could cause condensation formation on the respective documents. 

Isn’t the HVAC System Sufficient?

If your area experiences any type of seasonal changes, a building’s HVAC system will not offer sufficient condensation control. Manufacturers design heating and cooling systems to ensure occupant comfort, not preserve documents. While HVAC equipment does dehumidify the air a bit, it may not suffice in regards to maintaining the health of your stored materials, even if the building has different HVAC zones. Using an HVAC system for document storage purposes ultimately increases energy costs and reduce the equipment’s lifespan.

A more practical, economical solution for condensation control is the use of temporary climate control solutions that regulate temperatures, relative humidity levels and airflow. Polygon custom designs efficient systems that maintain ideal ‘round-the-clock conditions and work independently of HVAC systems. The integrated monitoring technologies further your peace of mind. While you can’t control seasonal weather changes, you can control the environment in which your organization stores its most valuable assets.