Overview
SIST EN ISO 15138:2018 (ISO 15138:2018) is the international standard for heating, ventilation, air‑conditioning (HVAC) and pressurization systems on offshore production installations in the petroleum and natural gas industries. It specifies requirements and guidance for the design, testing, installation and commissioning of HVAC systems for new and existing installations, whether normally occupied or not, and for fixed or floating units registered as offshore production installations.
This standard is intended to be used as the overall facility HVAC reference; where installations are subject to Class or IMO/MODU Codes & Resolutions, users should compare requirements - and apply ISO 15138 when fixed‑installation requirements are more stringent.
Key technical topics and requirements
- Design basis and system architecture: development of HVAC design basis, orientation, layout and ventilation philosophy (natural and mechanical ventilation).
- Hazard and environmental considerations: hazardous area classification, environmental loads and operational temperature ranges.
- Area‑specific requirements: process and utility areas, living quarters, temporary refuge, drilling areas, gas turbines, battery/charger rooms, laboratories, engine rooms, watertight compartments, air locks, stairs and escape routes.
- System performance & modelling: requirements for design margins, wind‑tunnel testing and computational fluid dynamics (CFD) modelling to verify ventilation and dispersion.
- Equipment selection and safety features: selection of HVAC equipment, filtration standards, fail‑safe criteria for fire dampers in safety‑critical areas, duct earthing requirements, purge air systems, and systems for rooms protected by gaseous extinguishing agents.
- Refrigerants and environmental policy: guidance on phase‑down/phase‑out of high and medium global warming potential (GWP) refrigerants.
- Commissioning, operation & maintenance: installation and commissioning procedures, black‑start requirements, and operation/maintenance guidance (normative and informative annexes provide datasheets and checklists).
Practical applications
- Establishing the HVAC design basis for offshore platforms and floating production units.
- Preparing technical specifications and datasheets for HVAC procurement and tendering.
- Conducting ventilation risk assessments, CFD and smoke/dispersion modelling.
- Implementing commissioning tests and acceptance criteria for HVAC systems.
- Ensuring HVAC systems meet safety, fire‑protection and environmental requirements (e.g., refrigerant selection, filtration).
Who uses this standard
- Offshore HVAC and mechanical engineers
- Platform designers and EPC contractors
- Offshore operators and asset owners
- Classification societies, certifiers and regulatory authorities
- HVAC equipment manufacturers and suppliers
- Commissioning and maintenance teams
Related standards and references
- IMO/MODU Codes & Resolutions and relevant Class rules (use in conjunction when applicable)
- Referenced ISO standards on acoustics, thermal insulation and related HVAC laboratory and test methods (normative references listed in the standard)
Using ISO 15138 helps ensure safe, compliant and environmentally responsible HVAC systems for offshore production installations, improving personnel safety, system reliability and regulatory alignment.
