Self-regenerating pre-adhesive strips for large volume enclosed spaces: electrical cabinets, containers, street furniture. 8x the useful capacity of silica gel in the risk zone (60-90% RH), zero maintenance, unlimited lifespan.
The problem
The outside temperature heats the enclosure. Internal pressure increases and air escapes.
Cooling reduces internal pressure. Humid outside air enters the enclosure.
Moisture accumulates. Condensation corrodes electronic components.
Large enclosed spaces — electrical cabinets, storage containers, EV charging stations, technical street furniture — are never perfectly airtight against water vapor. Temperature variations between day and night create a thermal breathing phenomenon: hot air escapes during the day, then humid outside air enters at night. Over successive cycles, internal relative humidity gradually increases until reaching the dew point, causing condensation on walls and internal components. This condensation leads to corrosion, leakage currents, degradation of stored materials and fungal growth. Conventional solutions such as silica gel saturate within a few months and must be replaced regularly, generating recurring costs and waste. The AS-C tape solves this problem by adsorbing excess water vapor and regenerating spontaneously at ambient temperature, without intervention or energy.
Principle
When relative humidity exceeds ~60%, the mesoporous material captures water vapor through capillary condensation.
Internal humidity is maintained below the condensation threshold. Components remain protected.
When the air dries out, the material naturally releases the adsorbed water. The cycle repeats indefinitely.
Technical data
×8
vs silica gel — risk zone (60-90% RH)
60%
RH threshold
IP65+
compatibility
0 W
power consumption
∞
lifespan
REACH
| Material | Mesoporous alumina (SRD) |
| Principle | Capillary condensation — adsorption/desorption |
| Adsorption capacity | 8x useful capacity vs standard silica gel (60-90% RH) |
| Activation threshold | ~60% relative humidity |
| Regeneration | Spontaneous at room temperature |
| Energy required | None (0 W) |
| Maintenance | None |
| Lifespan | Unlimited |
| Format | Self-adhesive tape |
| Mounting | Sticks directly onto internal wall |
| Patent | Filed May 2021 |
| Thickness | ± 1 mm |
| Operating temperature | -20°C to +70°C |
| Compliance | REACH — certificate available on request |
See all detailed comparisons by scenario →
Formats
Electrical cabinets, street furniture.
Large volumes: telecom shelters, toll booths, technical rooms.
⚠️ Physical limit reached: ramp clamped to 0.5 °C/min. Beyond this the model is outside its validity range.
Default: 0.043 °C/min (typical diurnal outdoor cycle for large-volume enclosures). Physical limit: 0.5 °C/min max (thunderstorm thermal shock). The faster the ramp, the more SRD strips you need.
Enter your parameters and click Calculate.
Comparison
5 approaches exist to fight condensation in sealed enclosures. The AS-C Sticker is the only passive, self-regenerating and maintenance-free solution.
| Criterion | Silica gel | AS-C Sticker (So Sponge) | Desiccant sticker (DesiMax, etc.) | Breather vent (GORE, AGM) | Heating element |
|---|---|---|---|---|---|
| Absorbs moisture | ✓ | ✓ ×8 risk zone | ✓ | ✗ | evaporates |
| Self-regenerating | ✗ | ✓ | ✗ | n/a | n/a |
| Zero energy | ✓ | ✓ | ✓ | ✓ | ✗ |
| Zero maintenance | ✗ replacement | ✓ | ✗ single-use | ✓ | ✗ monitoring |
| Lifespan | ~6 months | Unlimited | ~6 months | 3-5 years | 5-10 years |
| Integration | Loose sachet | Adhesive sticker | Adhesive sticker | Enclosure drilling | Wiring |
| Total cost (TCO) | High recurring | Low one-time installation | High recurring | Moderate | Very high energy + install |
Eco-design
Over 5 years, the AS-C Ribbon replaces a recurring consumable (calcium chloride) with a permanent passive solution — a direct lever for your eco-design and ESG objectives. Figures based on a storage container equivalent (~33 m³).
Across 100 installations equipped, ~4 tonnes of chloride avoided over 5 years, with no quarterly intervention or brine handling.
Assumptions: ~33 m³ installation, 2 kg tub replaced every 3 months, AS-C ribbon 4 m² (~800 g alumina) over 5 years. Learn more about our sustainability approach →
Use cases
The AS-C tape is designed for large volume enclosed spaces (> 1 m³). For small volume enclosures (sensors, IoT), see the AS-B format.
Electrical cabinets
Storage containers
EV charging stations
Street furniture
Automatic barriers
Telecom shelters
Outdoor payment terminals
Your application?
Contact usSimple
Choose the number of strips suited to the volume of your enclosed space.
Stick the pre-adhesive strips onto the internal surfaces of the enclosed space.
The AS-C Sticker operates autonomously. Zero maintenance.
Installation time: < 1 minute · Tools required: none
Evidence
← Swipe to see all tests →
So Sponge Team · Last updated March 23, 2026
The AS-C tape is an anti-condensation product from the AirSponge Enclosures range, designed for larger volume enclosed spaces. Based on the same mesoporous SRD (Self-Regenerating Desiccant) material patented by So Sponge, it adsorbs water vapor through capillary condensation when relative humidity exceeds approximately 60%, then spontaneously regenerates at room temperature. It operates without energy, without consumables and without maintenance.
The AS-B and AS-C use the same patented mesoporous SRD material. The AS-B comes as stickers for small volume enclosures (up to 100 L). The AS-C comes as pre-adhesive strips of 2 m × 8 cm, sized for large volume enclosed spaces (> 1 m³) such as electrical cabinets, containers and street furniture.
Installing the AS-C tape is simple and requires no tools. Choose the number of strips suited to the volume of your enclosed space, stick the pre-adhesive strips onto the internal surfaces, and the tape operates autonomously without any maintenance.
No. Thanks to the spontaneous regeneration of the SRD material, the AS-C tape never saturates and maintains its effectiveness indefinitely. Its lifespan is unlimited, it produces no waste and requires no maintenance.
During a test conducted in partnership with NEXTENEO in electric vehicle charging stations in an outdoor environment, the AS-C tape maintained indoor humidity below 80% continuously for nearly a year, preventing internal condensation. No performance degradation was observed throughout the entire test duration.
AirSponge is not yet UL Recognized at this stage. However, we can provide material data sheets, test results, and consider a UL submission if volume justifies it.
The AS-C tape is a zero-consumable, zero-collection-logistics and zero-replacement solution. Unlike calcium chloride tubs, which generate dozens of kilograms of waste (salt + corrosive brine) per installation over their lifetime, the AS-C stays in place for the full lifetime of the installation. A direct lever for your eco-design and ESG objectives. Learn more about our sustainability approach →
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