Overview
EN ISO 8861:1998 - "Shipbuilding - Engine-room ventilation in diesel-engined ships - Design requirements and basis of calculations" (ISO 8861:1998) defines design requirements and calculation methods for engine-room ventilation on diesel‑engined ships under normal service conditions. The standard establishes mandatory calculation bases (airflow for combustion and for heat evacuation), design assumptions (e.g. ambient temperature +35 °C, permitted temperature rise 12.5 K) and informative guidance (Annex A) on good practice for distribution, exhaust and safety features.
Key topics and technical requirements
- Design conditions
- Ambient air temperature assumed: +35 °C
- Maximum temperature rise through engine room: 12.5 K
- Total airflow (Q)
- Q = qc + qh (sum of combustion airflow and heat‑evacuation airflow) or Q ≥ 1.5 × qc (combustion air + 50%), whichever is larger.
- Airflow for combustion (qc)
- Separate calculations for main propulsion engines (qdp), diesel generators (qdg) and boilers (qb) using service standard power, specific air requirement (mad), and air density (r = 1.13 kg/m3).
- Airflow for heat evacuation (qh)
- Based on summed heat emissions from engines, generators, boilers, piping, electrical installations, exhausts and other equipment, using specific heat capacity c = 1.01 kJ/(kg·K) and ΔT = 12.5 K. A factor (0.4) reflects typical arrangements; may be adjusted for special layouts.
- Heat emission calculations
- Methods and example default values for heat loss percentages, boiler/thermal heater emissions, exhaust pipe losses, hot‑tank surface emissions (tabled values), and electrical heat loads.
- Design guidance (Annex A)
- Air distribution (≈50% to level of engine turbocharger), maintain slight positive pressure (normally ≤ 50 Pa), separate exhaust for purifier/fuel‑oil rooms, and fire dampers per SOLAS requirements.
Practical applications
- Use for HVAC and ventilation design of engine rooms on cargo ships, tankers, naval vessels and passenger ships with diesel propulsion.
- Inputs for naval architects, marine HVAC engineers, shipyards, system integrators and classification societies to:
- Size ventilation fans and ducts
- Determine combustion‑air intake and distribution
- Verify cooling/heat‑removal capacity to protect heat‑sensitive equipment
- Ensure regulatory and safety alignment with SOLAS and load‑line requirements
Who should use this standard
- Ship designers and naval architects
- Marine HVAC/mechanical engineers and consultants
- Shipbuilders and shipyard design teams
- Classification societies and regulatory authorities
- Marine equipment manufacturers (engines, fans, exhaust systems)
Related standards and references
- ISO 3046‑1 (engine performance and service power)
- ISO 31 parts 1, 3, 4 (quantities and units)
- ISO 3258 (air distribution vocabulary)
- SOLAS II‑2 and International Load Line Convention - referenced for fire dampers and closing appliances
Keywords: EN ISO 8861:1998, engine-room ventilation, diesel-engined ships, ventilation airflow, heat emission, marine ventilation, shipbuilding standards, ventilation design calculations.