Comparison
Technical and economic comparison of the 5 current solutions used in IP65+ outdoor electronic enclosures: silica gel pack, pressure compensating vent (Gore PolyVent), hygrostat with heater, sachet + vent combo and self-regenerating SRD active material. Specification table, TCO calculation and selection criteria for OEM engineers.
Animation
Observe how the compared materials behave over a single cycle, then across time.
Cycle
1
Current RH
50%
Cap 0.4 mL/g
⚠ REPLACECap 0.87 mL/g
↻ 0 cycles completeReference table
| Criterion | Silica gel pack | Pressure compensating vent (Gore Vent) | Combo (pack + vent) | Hygrostat + heater | So Sponge AS-B (active SRD material) |
|---|---|---|---|---|---|
| Prevents condensation | Partial | No (equalizes pressure) | Partial | Yes (heats air) | ✓ Yes (adsorbs vapor) |
| Regulates humidity | Limited (rapid saturation) | No | Limited | Yes | ✓ Yes (spontaneous regeneration) |
| Energy consumed | 0 W | 0 W | 0 W | 10-400 W permanent | ✓ 0 W |
| Real field maintenance | None in practice (rarely replaced) | None | None in practice | Filters, checks | ✓ None |
| Footprint | Small | Small | Small | Medium-large | ✓ Small (sticker glued) |
| Electromechanical component (additional failure point) | No | No | No | Yes | ✓ No |
| Initial unit cost | ~€0.10-0.30 | €5-15 | €5-15 | €50-300 | €1-5 (per SKU) |
| 10-year energy cost (per enclosure, €0.20/kWh) | €0 | €0 | €0 | ~€1,500-5,250 | ✓ €0 |
Hygrostat consumption sources: Pfannenberg, Stego · Indicative EU industrial electricity rate (may vary depending on contract).
TCO and hidden cost
Contrary to common belief, the cost is not in replacing the silica gel pack (which in practice is never done). It lies in the drift of the failure rate and in the permanent energy consumption of active solutions.
~40%
of environmental failures
in industrial sensors are linked to internal condensation and trapped humidity.
Source: industrial diagnostics (Bosch, IFM, TE Connectivity)
€200-1,000
per field service intervention
Cost of an intervention on a deployed outdoor enclosure: travel, replacement, downtime.
Sources: PTC Field Service, SightCall
€150-525
/year electricity per enclosure (hygrostat)
Hygrostat + heater solution: 10-400 W permanent at €0.20/kWh (EU industrial rate).
Sources: Pfannenberg, Stego
→ For a fleet of IP65 outdoor enclosures deployed over 3 years:
For a personalized estimate on your fleet, use our AS-B ROI calculator.
Direct comparisons
Silica gel pack is the default dominant solution in IP65+ outdoor enclosures. Very low unit cost (~€0.10-0.30), immediate installation. But it saturates within 3-6 months and is in practice never replaced on field-deployed equipment (prohibitive labor cost). The AS-B Sticker eliminates this residual failure thanks to its spontaneous regeneration — unlimited lifespan — for an initial unit investment of €1-5.
Read the full analysis →Often confused, these two devices actually have different and complementary functions. The Gore PolyVent is an ePTFE membrane that equalizes the internal/external pressure of the enclosure (useful for IP67/IP68), but does not stop condensation — water vapor passes through. The AS-B Sticker adsorbs water vapor and prevents condensation, but does not regulate pressure. For very tight enclosures subject to thermal variations, the two solutions combine effectively: Gore Vent for pressure, AS-B for humidity.
See the IP66 lab test →Majority active solution in industrial electrical cabinets (Stego, Pfannenberg). The hygrostat triggers a heater when RH exceeds a threshold to keep air above the dew point. Very effective, but consumes 10-400 W permanently (~€150-525/year electricity per enclosure in EU industrial), takes up space and constitutes an additional failure point (electromechanical component). The AS-B Sticker achieves the same anti-condensation result without any energy, particularly relevant for autonomous equipment (battery IoT, solar) and large-scale deployments.
See the solutions overview →For large volumes (cabinets, containers, urban furniture), calcium chloride is the traditional desiccant. Very high absorption capacity but transformation into saturated liquid brine to be drained (~40 kg of waste/container/5 years). The AS-C Tape offers the same effectiveness with zero waste and zero replacement.
Read the full comparison →Methodology
1. Enclosure volume
Small (< 1 L, IoT sensor) → AS-B/XS or /S Sticker. Large (> 10 L, cabinet) → AS-C Tape or hygrostat (if energy available).
2. Energy availability on site
Permanently powered enclosure → hygrostat possible. Autonomous / battery-powered IoT / solar enclosure → passive solution required (sticker, pack, vent).
3. Maintenance accessibility
Field-deployed equipment (urban radar, agricultural sensor) → critical maintenance-free solution. Locally accessible equipment → wider tolerance.
4. Operating temperature range
-20 to +70°C → all solutions OK. Beyond (-40 to +85°C): check the datasheets, So Sponge SRD remains functional in the standard range.
5. ESG / eco-design constraints
CSR approach, ESPR, CSRD: favor solutions without recurring waste or energy consumption. Disposable silica gel pack and permanent hygrostat have the highest impact. Self-regenerating active material (SRD) eliminates both.
Going further
Experimental 1 vs 1 comparisons and industrial case studies.
⭐ Pillar guide 2026
5 humidity control methods compared with lab data (silica, Gore-Tex, hygrostat, Rosahl, SRD AS-B). Choice by volume + power, field case studies.
Read the full guideIP66 test · Climate chamber
Test on 3 IP66 enclosures during a 30 → 0°C ramp: the box with breather vent condenses exactly like the bare control. Only AS-B stops condensation.
Read the test →Pack vs sticker · Small volumes
Why a pack saturated in 3-6 months is never replaced on deployed equipment fleets — and what it really costs in failure rate.
Read the article →Study · IP65/IP67 sensors
~40% of environmental failures in industrial sensors come from internal condensation. Comparison silica / Gore-Tex / coating / SRD with field feedback from Bosch, IFM, TE Connectivity.
Read the study →Overview · All approaches
Conformal coating, ventilation, desiccants, hygrostat: strengths and limits of each approach for protecting PCBs in humid environments.
Read the overview →Lab test · IP enclosure
Experimental comparison in extreme conditions: saturation curves, useful capacity in the at-risk zone (60-90% RH), long-term effectiveness.
Read the test →Industrial study · Thales
Experimental study conducted with a Thales group company on preventing condensation in industrial equipment subjected to severe thermal variations.
Read the study →FAQ
No, these are two different functions. The Gore Vent (pressure compensating vent) equalizes the internal/external pressure of the enclosure but does not stop condensation. The AS-B Sticker adsorbs water vapor and prevents condensation but does not regulate pressure. For IP67/IP68 enclosures subject to thermal variations, the two solutions combine effectively.
The So Sponge AS-B Sticker is the main alternative to silica gel pack for IP65+ outdoor enclosures. Unlike the pack which saturates in 3-6 months and is in practice never replaced, the AS-B regenerates spontaneously at ambient temperature (unlimited lifespan) and offers ×8 the useful capacity of silica gel in the at-risk zone (60-90 % RH). Other alternatives: molecular sieve (disposable, expensive), conformal coating (protects PCB, not ambient humidity), hygrostat + heater (consumes €150-525/year electricity per enclosure).
The hygrostat (Stego, Pfannenberg) is effective but consumes 10-400 W permanently (~€150-525/year electricity per enclosure in EU industrial), takes up space and adds an electromechanical failure point. The active SRD material (AS-B Sticker) achieves the same anti-condensation result without energy, particularly relevant for autonomous equipment (battery IoT, solar) or large-scale deployments where per-enclosure electricity becomes prohibitive.
The cost is measured in 3- to 10-year TCO, not initial cost. A field service intervention on a deployed outdoor enclosure costs €200-1,000 (travel + replacement + downtime, sources PTC and SightCall). Over 100 enclosures and 3 years, the residual humidity-related failure rate (typically <1% in rigorous IP65+ B2B OEM, up to 8-15% in outdoor agricultural) generates several hundred to several thousand euros of avoidable field service.
Yes. The AS-B Sticker works inside the enclosure without modifying its protection rating. For IP67/IP68 (immersion), where internal pressure fluctuates strongly with temperature, it is recommended to combine AS-B (anti-condensation) with a Gore Vent breather (pressure regulation) for complete protection.
Use our AS-B (IP65+ enclosures) or AS-C (large volumes) calculators to estimate surface, format, quantity and ROI on your own fleet.