A protective membrane vent allows pressure equalization while resisting specified contaminants. Water vapor can pass both ways, so a vent is not a one-way dryer or proof of humidity control. Gore’s FAQ explains this distinction.
Why condensation can remain
Gore describes vapor escaping until the enclosure and surroundings reach equilibrium. That can reduce trapped condensation; it does not establish a target RH or eliminate condensation in every operating condition. Liquid-water resistance is not vapor impermeability.
Give each control method a defined job
A heater changes temperature; an active dehumidifier removes water from air. Assess the cold surface, local dew point and moisture source before selecting either. Our heater, ventilation and dehumidifier comparison explains those choices. A supplier’s claim about venting should be evaluated separately from the moisture-control requirement.
Specify the assembled enclosure
Donaldson’s selection guide treats protection, airflow and attachment together. More water resistance can restrict airflow; unsuitable attachment can compromise an otherwise suitable vent. Request the following evidence for the intended assembly:
| Review item | Evidence to request |
|---|---|
| Protection | Candidate vent documentation and the finished enclosure’s applicable protection evidence |
| Pressure response | Expected pressure changes and the airflow basis used for this enclosure |
| Attachment | Substrate, environmental compatibility and approved assembly method |
A component rating alone does not establish the finished enclosure’s rating. Leave vent size, quantity and installation details to the enclosure designer and supplier.
Keep a review record
Use a short decision record to make the supplier’s answer traceable. The following is a proposed handoff format, not a test standard or a completed project result.
- Identify the enclosure revision and candidate part revision; attach the documents actually reviewed.
- Separate observed conditions from assumptions. Mark missing information rather than filling it with a typical value.
- Record each open question, its owner and the evidence needed to close it.
- Ask the responsible project engineer to define acceptance criteria before testing. Record the tested assembly, procedure revision, observations and decision against those criteria.
- Retain unresolved questions with the decision. Reopen the review when the proposed configuration changes.
This guide addresses normal enclosure pressure equalization. It provides no qualification for emergency pressure relief or battery safety functions.
If the project also needs active moisture removal, share its operating conditions with Yakeclimate for equipment discussion. Keep the vent supplier’s assembly decision and the moisture-removal equipment decision explicit.
