Separate air quality, ventilation performance and thermal comfort.
An onboard indoor-air-quality investigation asks which measured environmental conditions or contaminants relate to an occupied-space question. A ship HVAC and ventilation performance survey asks how outdoor, supply, return, transfer and exhaust air move through the installed system and whether the achieved operation matches the agreed design or commissioning basis. A thermal-comfort survey evaluates the human thermal environment using the selected temperature, radiant, humidity, air-speed, clothing and activity inputs.
| Observed problem | Primary evidence route | Supporting evidence | Do not conclude from one reading |
|---|---|---|---|
| Stuffy cabin, odour, irritation, fumes, dust or suspected source | IAQ investigation and targeted sampling | Occupancy, source history and ventilation state | Cause, exposure or compliance without an applicable basis and valid strategy |
| Weak supply, uneven distribution, poor exhaust or pressure transfer | HVAC airflow and pressure-path diagnosis | System drawings, settings and operating state | Outdoor-air delivery from total recirculated airflow alone |
| Too hot, cold, humid, draughty or affected by radiant heat | Thermal-environment assessment | HVAC state, weather, occupancy and heat loads | Comfort or heat-stress status from dry-bulb temperature alone |
The ship IAQ and thermal-comfort guide explains why coordinated measurement can reveal interactions. Coordination does not make CO₂ a universal fresh-air meter, make grille velocity an air-change result, or turn a comfort index into proof that a contaminant source is absent.
Write the report decision before selecting instruments.
Record whether the attendance supports complaint diagnosis, pre-delivery commissioning, post-refit verification, occupied-space monitoring, source tracing, a maintenance decision or review against a named vessel, contract, flag, class, company or project requirement. Identify the recipient and acceptance owner. A standard can define a planning or calculation method without supplying the applicable limit for every vessel or space.
| Scope ID | Decision / recipient | Space and population | Requirement / edition | Quantity and condition | Witness / reviewer | Open limitation |
|---|---|---|---|---|---|---|
| SCOPE-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| SCOPE-___ | ___ | ___ | ___ | ___ | ___ | ___ |
ISO 16000-1 supports planning indoor-pollution monitoring by clarifying why, when, where, how often and for how long measurements are required. ISO 7547:2022 defines ship accommodation ventilation and air-conditioning design conditions and calculation bases. Neither reference should be relabelled as an automatic field pass criterion without the actual project basis.
Turn general discomfort into traceable observations.
Assign each cabin, office, control room, medical room, galley-adjacent space or other occupied compartment a stable identifier. Capture deck and frame, function, typical and maximum occupancy, complaint wording, onset, duration, time of day, voyage or port context, recent work, cleaning products, stored materials, water ingress, visible dampness, nearby exhausts and whether symptoms or odours change when a door, fan or machinery item changes state.
| Space ID | Use / occupancy | Complaint / observation | Onset / timing | Nearby source or work | Ventilation state | Comparison space |
|---|---|---|---|---|---|---|
| SPACE-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| SPACE-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| SPACE-___ | ___ | ___ | ___ | ___ | ___ | ___ |
Select reference spaces deliberately. A nearby unaffected cabin can help isolate distribution or source differences, while an outdoor or intake reference can support source interpretation. A reference is not automatically a blank sample, background value or exposure limit.
Trace intake, treatment, distribution, transfer and exhaust.
Use drawings and a walk-through to identify outside-air intakes, louvers, dampers, filters, coils, drain pans, humidification or dehumidification components, fans, branch ducts, fire dampers, silencers, terminal devices, returns, transfer grilles and exhaust outlets serving each space. Record potential cross-connections, recirculation, leakage, short-circuiting and proximity to engine, galley, sanitary, cargo, smoking, cleaning or maintenance sources.
| Path ID | Intake / source | AHU / fan / filter | Branch / terminal | Return / transfer / exhaust | Observed defect | Evidence needed |
|---|---|---|---|---|---|---|
| PATH-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| PATH-___ | ___ | ___ | ___ | ___ | ___ | ___ |
Do not infer flow direction from grille type or drawing arrows alone. Confirm actual operation where safe and authorised. Photos, marked drawings and stable equipment identifiers should allow another engineer to understand which air path was assessed and which sections remained inaccessible.
Freeze the vessel state around every valid interval.
Record berth, anchorage, shipyard, dry-dock, harbour-trial, sea-trial or in-service context; weather; heading and wind relation; propulsion and generator state; shore power; cargo or hotel load; HVAC mode; outside-air damper position; fan speed; filter and coil condition; set points; doors and windows; occupancy; cleaning or maintenance; galley and sanitary exhaust; and any temporary ventilation. Mark the requested state and the achieved state separately.
| Run / UTC | Vessel / weather | Generation / load | AHU / fan / damper | Doors / occupancy / activity | Source event | Valid / repeat / qualify |
|---|---|---|---|---|---|---|
| RUN-01 / ___ | ___ | ___ | ___ | ___ | ___ | ___ |
| RUN-02 / ___ | ___ | ___ | ___ | ___ | ___ | ___ |
| RUN-03 / ___ | ___ | ___ | ___ | ___ | ___ | ___ |
A short quiet inspection may not represent an occupied voyage condition. Conversely, a transient maintenance or cleaning event may not represent normal service but can be essential to a complaint investigation. State which condition each result represents instead of averaging unlike periods together.
Select measurements from the question and source hypothesis.
Possible field quantities or samples may include carbon dioxide, carbon monoxide, temperature, relative humidity, particles, selected volatile compounds, formaldehyde, microbial indicators or another project-specific agent. Selection depends on the complaint, source, timing, required decision, analytical method and competent risk review. A broad sensor cannot identify every compound, and a non-detect result is meaningful only with the method, detection capability, duration and condition.
| Question / hypothesis | Quantity or sample | Method / laboratory | Location / height | Duration / timing | Reference / blank / QA | Interpretation boundary |
|---|---|---|---|---|---|---|
| IAQ-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| IAQ-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| IAQ-___ | ___ | ___ | ___ | ___ | ___ | ___ |
An occupied-space spot measurement is not automatically a personal occupational exposure assessment. Where an exposure decision is required, use the applicable agent-specific strategy, duration, averaging basis, laboratory and occupational requirement. Do not infer a medical diagnosis from environmental data.
Define the quantity before putting a meter at a grille.
Record whether the required result is point velocity, area-averaged face velocity, terminal volume flow, duct flow, outdoor-air flow, exhaust flow, transfer flow, air-change estimate or distribution comparison. Select a method that suits the terminal geometry, swirl, turbulence, accessibility and expected range. Document the effective area or hood setup used in any conversion and avoid multiplying one convenient peak velocity by a nominal grille area.
| Point / system | Required quantity | Instrument / method | Area / traverse / hood | Fan / damper state | Result / uncertainty | Drawing / photo |
|---|---|---|---|---|---|---|
| AIR-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| AIR-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| AIR-___ | ___ | ___ | ___ | ___ | ___ | ___ |
ISO 7547:2022 provides design conditions and calculation bases for accommodation and certain other enclosed compartments on seagoing merchant ships. It does not make every field instrument arrangement valid or replace the vessel drawing, approved calculation, commissioning procedure, contract requirement or reviewer instruction.
Follow the flow path through doors and boundaries.
Where odour transfer, exhaust ingress or pressure relationship is the concern, record the spaces on both sides of the boundary, door position, fan and damper states, transfer openings, leakage routes, measured pressure difference, smoke or tracer observation if authorised, and the intended direction. Check whether supply, return and exhaust measurements are reasonably reconcilable within their method limitations.
| Boundary ID | Spaces / door state | Supply / return | Transfer / leakage | Exhaust | Pressure / direction | Finding / limitation |
|---|---|---|---|---|---|---|
| BOUND-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| BOUND-___ | ___ | ___ | ___ | ___ | ___ | ___ |
Pressure direction can reverse with door operation, wind, stack effect, fan staging or adjacent exhaust. A single reading without the boundary and operating state cannot establish persistent containment or transfer. Where safety-critical ventilation is involved, follow the responsible authority and vessel procedure.
Connect every result to the actual measurement system.
Identify direct-reading monitors, temperature and humidity sensors, anemometers, flow hoods, differential-pressure instruments, pumps, media, blanks and any data logger used. Record make, model, serial number, measurement range, resolution where relevant, calibration certificate and validity, field or zero checks, configuration, clock source and environmental limitations. For laboratory samples, add media lot, pump flow checks, sample volume, preservation, custody, transport and analytical method.
| Equipment / sample ID | Make / model / serial | Range / method | Certificate / due date | Pre / post check | Clock / custody | Disposition |
|---|---|---|---|---|---|---|
| INST-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| SAMPLE-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| INST-___ | ___ | ___ | ___ | ___ | ___ | ___ |
A calibration certificate supports traceability but does not validate the selected location, duration, sample handling, cross-sensitivity, effective grille area, traverse, system state or acceptance criterion. Those controls remain separate report evidence.
Align people, sources, system changes and measurements.
Use a common time reference for field instruments, BMS or control-panel data, machinery logs, occupancy observations and sample start/stop times. Record fan changes, damper commands, door openings, cleaning, cooking, smoking where applicable, maintenance products, cargo or engine events, weather changes and complaint observations. Mark invalid intervals rather than smoothing them invisibly into averages.
| UTC / local time | Space / channel | Occupancy / activity | HVAC command / actual state | Source event | Observed response | Keep / reject / qualify |
|---|---|---|---|---|---|---|
| ___ | ___ | ___ | ___ | ___ | ___ | ___ |
| ___ | ___ | ___ | ___ | ___ | ___ | ___ |
| ___ | ___ | ___ | ___ | ___ | ___ | ___ |
Correlation supports a hypothesis but does not automatically prove causation. Use controlled comparisons, repeated patterns, source-specific evidence and the physical air path to decide whether a finding is supported, plausible, unresolved or contradicted.
Change one authorised condition at a time where practical.
A safe, authorised change can distinguish ventilation delivery, source generation and transfer mechanisms. Examples include a fan stage, outdoor-air damper position, filter state, door position, local exhaust, temporary source removal or occupancy state. Record the baseline, exact change, expected response, measurements held constant, actual response, safety approval and restoration. Do not adjust fire dampers, protections, hazardous-area ventilation or essential machinery solely for diagnosis without proper authority and risk control.
| Test ID | Baseline | One authorised change | Expected IAQ / flow response | Channels held constant | Observed result | Restored / approved by |
|---|---|---|---|---|---|---|
| CHANGE-___ | RUN-___ | ___ | ___ | ___ | ___ | ___ |
| CHANGE-___ | RUN-___ | ___ | ___ | ___ | ___ | ___ |
ISO 8861:1998 addresses engine-room ventilation design requirements and calculation bases for diesel-engined ships. It is not an accommodation IAQ criterion and is not a universal field-balancing procedure. Use it only where its scope and the actual machinery-space decision apply.
Keep measurements, engineering judgement and acceptance distinct.
For each finding, identify the supporting space, time, operating run, source-path evidence, instrument or sample, method, comparison basis, uncertainty or limitation and decision owner. Label preliminary observations clearly. Recommendations may involve maintenance, cleaning, intake relocation review, sealing, damper or control investigation, filter or coil work, air balancing, source control, more specific sampling or a matched retest; implementation remains with authorised responsible parties.
| Finding ID | Evidence and condition | Supported / plausible / unresolved | Responsible action | Retest controls | Acceptance owner | Close-out status |
|---|---|---|---|---|---|---|
| FIND-___ | ___ | ___ | ___ | ___ | ___ | ___ |
| FIND-___ | ___ | ___ | ___ | ___ | ___ | ___ |
A matched retest should repeat the affected spaces, instrument methods, locations, durations, occupancy and vessel/HVAC state as closely as practicable. State every unavoidable difference. An improvement in one parameter does not prove that every air-quality, ventilation or comfort question is closed.
Prepare useful first-party evidence without inventing a vessel case.
Decision and complaint
What occupied-space or system question triggered the investigation, and who owned the decision?
Controlled scope
Which spaces, people, sources, ventilation paths, parameters and conditions were included?
Traceable evidence
Which time-aligned measurement, sample, airflow and pressure records support the finding?
Finding boundary
What was supported, what remained plausible, and what was outside the measurement scope?
Action and verification
Which authorised response and matched retest were completed, and which differences limited comparison?
Publication permission
Who approved disclosure, which identifiers and values were removed, and which text or images may be shown?
This is a blank evidence structure, not a completed customer project. Do not add a vessel, owner, yard, operator, class, flag, complaint, illness, contaminant, airflow, failure, pass statement, correction, numerical improvement, testimonial or business result without contemporaneous records and written publication permission.
Use current documents within their actual scope.
- ISO 16000-1:2004 provides general aspects of indoor-air sampling strategy and was confirmed current in 2024.
- ISO 7547:2022 covers ship accommodation air-conditioning and ventilation design conditions and calculation bases.
- ISO 8861:1998 addresses engine-room ventilation design requirements and calculation bases and was confirmed in 2022.
- ISO 16000-40:2019 specifies an indoor-air-quality management system; it is not a universal concentration-limit table or a substitute for agent-specific sampling.
- ISO 16000-40:2019/Amd 1:2024 is the published climate-action amendment to that management-system document.
Confirm the vessel type, applicable regulations, flag, class, approved drawings, contract, company procedures, laboratory requirements and report recipient before testing. Supplier qualification, class recognition, flag authorisation, surveyor witnessing and acceptance of a particular report are separate questions. Vessel Doctor does not claim that these references confer approval, guaranteed attendance, turnaround or acceptance.
Convert the blank record into a focused onboard investigation.
Provide the vessel and space particulars, complaint or commissioning question, affected people and timing, ventilation drawings, operating window, recent work or suspected sources, required measurements or criteria, reporting recipient and any access or safety restrictions. The IAQ, airflow and thermal routes can then be scoped separately and aligned where useful.
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