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Humidity Control Sheets

The One and Done Solution for Preventing Condensation in Sealed Enclosures
Protect sensitive equipment and components from excess moisture No Desiccants. No De-humidifiers. No Hygrostats. No power required.

Active-S Humidity Control Sheets
Manufactured Products


Active-S Humidity Control Sheets stop moisture from collecting and forming condensation to protect sensitive components and systems. Active-S is a highly effective, easy to install sheet that controls humidity levels and prevents these common problems inside sealed enclosures and cabinets:

  • Component corrosion
  • Electrical resistance
  • Component performance degradation
  • Short circuits
  • Deteriorating electrical wires
  • Dangerous arching & sparking

Purchasing Information

Quality & Value

Active-S Humidity Control Sheets are Designed for These Applications

With more than 1.6 million sheets installed in communications equipment, terminal boxes and protection devices; Active-S sheets work.

Communication Equipment • Construction Equipment • Control Panels • Drones • EV Charging Stations • Food and Beverage • Gun Safes • Manufacturing Equipment • Monitoring Sensors • Oil & Gas Optical Devices • M2M Devices • Marine Enclosures • Radar • Railroad Infrastructure • Security & Monitoring Cameras • Ships & Vessels • Telecom Base Stations • Traffic Controls Utilities, and more...

Designed to control humidity in enclosures for these environments:

  • Places where electrically powered dehumidifier equipment is not practical
  • Factory wash-down application or locations with temperature and humidity fluctuations
  • Enclosures when panel door is opened and closed for service or maintenance
  • Enclosures located where equipment and facilities are not easily accessible
  • Enclosures from operating temperature changes created by equipment shutdowns
  • Storage enclosures for instruments and art objects that are susceptible to moisture and mold environments
  • A wide variety of other applications that require mitigating condensation within enclosures


Only Active-S Controls Humidity by Absorbing and Releasing

The Active-S "Humidity Control Sheet" is a highly effective equipment maintenance product that prevents condensation, utilizing a special active fabric developed for a major Japanese telecommunications provider.

Active-S is not a desiccant Active-S Humidity Control Sheets are made of a macromolecule polymer, which is a super-absorbent material that "breathes," providing an active exchange of absorption and release. When humidity in the enclosure is high, the humidity control sheet absorbs the excess moisture, reducing humidity levels inside the cabinet. But when the cabinet becomes dry, the sheet "breathes out" the moisture, maintaining relative humidity at under 60% in the cabinet at all times.

Humidity Control Sheet Humidity (Hygrometric) Measurement Test

  • Volume capacity of box used for testing: 13.9 liter (ø5mm vent hole in bottom)
  • Humidity Control Sheet (post-card size) installed on lid
  • Measurement location: outdoors location in Hachioji City, Tokyo
  • Measurement time period: 2 weeks

View Active-S Presentation

  • Consistently maintains humidity level at or under 60% by absorbing and releasing moisture in the air
  • Fits any size enclosure, even tight spaces and curved surfaces
  • Requires no space, no maintenance, no power source
  • Long usage life - 10 years of proven field testing
  • Significantly reduces time and labor costs
  • Installs with double-sided tape, Velcro or magnetic tape
  • No moving parts to fail
  • Four sizes to suit enclosure capacity
  • Lowest applied cost

Simplify your Design, Lower your Cost

Conventional desiccants do not perform well after absorbing certain amount of moisture. ehumidifiers and hygrostats take up space and require power. No need for that anymore. The superior breathing characteristic of Active-S Humidity Control Sheets maintain high performance over a long period of time.
  • Simplified installation
  • No need for maintenance
  • High performance over a long period of time
  • Time and labor costs are significantly reduced
  • Lowest cost solution for controlling humidity

There are four different sizes to choose from to suit the capacity of the enclosures.

Calculate Active-S Size for Your Requirement

  • measure enclosure inside dimensions
  • Width(W) x Depth(D) x Height(H) = Cubic inches

Example 1:
Interior dimensions of cabinet: 20” Wide x 18” Deep x 24” High
Volume: 20 x 18 x 24 = 8,640 cubic inches
From the table, one AS-M will do up to 9,154 cubic inches

Example 2:
Interior dimensions of cabinet: 18.5” Wide x 14” Deep x 24” High
Volume: 18.5 x 14 x 24 = 6,216 cubic inches
From the table, one AS-M will do up to 9,154 cubic inches but 14.6” width of AS-M is greater than 14” depth of cabinet so to install sheet on side surface use 4 of the AS-P sheets

Precautions for Use

  • Take adequate measures to keep water out of cabinets before installing Humidity Control Sheet
  • The standard application is intended for use in a sealed space.Changes in usage environments may affect results.