Keep IAQ, ventilation and comfort on separate evidence tracks.
An onboard indoor-air-quality investigation selects measurements or samples according to the complaint, suspected contaminant and source pathway. A ship HVAC and ventilation survey measures system delivery, distribution and pressure behaviour against an agreed requirement. Thermal comfort can depend on the same system, but temperature, radiant conditions, humidity, air speed, clothing and activity require their own decision route.
State the affected space or group, decision question, metric and units, governing contract or reference, authorised owner and excluded conclusion. Carbon dioxide can help interpret occupancy and ventilation but does not identify every contaminant. A supply-flow result does not by itself establish air quality, health effect or comfort. Do not combine unlike results into one pass score.
| Finding | Evidence track | Decision question | Metric / units | Basis / edition | Decision owner | Excluded conclusion |
|---|---|---|---|---|---|---|
| DEC-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| DEC-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| DEC-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Freeze the evidence that justified corrective action.
Retain the report revision, space and deck reference, measurement or sample identifier, method, instrument and calibration chain, field checks, laboratory and custody records, detection or reporting limits, uncertainty where relevant, occupancy, HVAC mode, outdoor condition, vessel activity, time line, accepted deviations and raw-file location. Link this record to the earlier IAQ and HVAC investigation field record.
Classify the finding as a measured exceedance against the stated basis, an agreed performance shortfall, an intermittent source-path observation, an unresolved complaint, a commissioning deficiency or an information gap. If the baseline did not represent the complaint period or required system condition, correct the measurement strategy before authorising a costly modification. Preserve superseded results with a traceable reason.
| Finding | Report / revision | Baseline result | Represented condition | Uncertainty / limitation | Raw evidence | Reason for action |
|---|---|---|---|---|---|---|
| BASE-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| BASE-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| BASE-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Test the mechanism before choosing the remedy.
List plausible indoor sources, outdoor intakes, exhaust re-entry, transfer paths, moisture reservoirs, filtration faults, fouled coils or drains, blocked terminals, damper or control errors, fan condition, duct leakage, pressure imbalance, capacity limits and measurement artefacts. For each hypothesis, state the expected spatial or time signature and a safe discriminating observation.
Useful evidence can include time-aligned direct readings, targeted laboratory samples, indoor-to-outdoor comparison, smoke-free pressure-path checks, grille and damper inspection, filter and coil records, flow traverses, repeated equipment states and system drawings. A correlation with one operational event does not automatically prove cause. Record alternatives, evidence strength and what would falsify the hypothesis.
| Hypothesis | Expected signature | Controlled check | Observed evidence | Alternative cause | Confidence | Next decision |
|---|---|---|---|---|---|---|
| CAUSE-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| CAUSE-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| CAUSE-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Match the control to the identified source or pathway.
Potential actions may include removing or isolating a source, repairing exhaust separation, changing work timing or material use, cleaning a verified reservoir, correcting moisture ingress, repairing drainage, replacing a suitable filter, improving outdoor-air delivery or stopping transfer from a contaminated zone. The selected control depends on the actual evidence, safe vessel operation and the authorised design or management route.
For each action, record the targeted contaminant or indicator, source or path, predicted effect, affected spaces, unintended risk, temporary or permanent status and verification measurement. A generic cleaning activity or filter change is not proof of source removal. Microbial, chemical and particulate questions may require different methods, competent laboratories and interpretation boundaries.
| Action | Finding / source | Proposed control | Predicted effect | Unintended risk | Authority / instruction | Verification metric |
|---|---|---|---|---|---|---|
| IAQ-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| IAQ-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| IAQ-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Define the design intent and system consequence before adjustment.
Actions may include fan or belt maintenance, damper and control correction, terminal balancing, duct or seal repair, filter review, intake or exhaust modification, sensor verification, setpoint correction, condensate repair or a design change. Record the system, branch, terminal, fan state, design or commissioning target, predicted air-path effect and every neighbouring space that could be affected.
Do not chase one weak terminal by moving several dampers without retaining the initial setting and system balance. A higher measured flow can create noise, drafts, pressure reversal, energy use, condensation or reduced delivery elsewhere. Safety-critical ventilation, hazardous zones, machinery spaces and fire arrangements require the applicable competent and authorised review before work.
| Action | System / location | Baseline duty | Proposed change | Predicted effect | System risk | Commissioning target |
|---|---|---|---|---|---|---|
| HVAC-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| HVAC-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| HVAC-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Record what changed before testing again.
Retain the approved work instruction or drawing, component identity, filter specification where relevant, damper or control setting, terminal position, seal or duct repair, cleaning method, responsible person, completion date, photographs where permitted, quality checks and deviations from the proposal. For operational controls, retain the issued procedure, effective date, responsible watch and evidence of implementation.
A recommendation and an installed condition are different states. If executed work differs from the proposed action, reassess the predicted effect and verification plan. Multiple simultaneous changes weaken causal attribution; report that limitation instead of crediting the full measured difference to one item. Keep the baseline data immutable and version any reprocessing.
| Action | Approved reference | Installed state | Setting / component | Deviation | Completion evidence | Configuration owner |
|---|---|---|---|---|---|---|
| IMP-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| IMP-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| IMP-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Verify function before repeating the IAQ decision.
Commissioning should confirm the changed system or component operates as intended and has not displaced the problem. Record fan and control mode, stable operating period, relevant supply, outdoor, return and exhaust quantities, representative terminal flows, pressure relationships, damper and filter state, alarms, drainage, noise or draft observations and adjacent-space consequences. Use the approved measurement method and correction factors.
Design standards such as ISO 7547:2022 and ISO 8861:1998 provide calculation context within their scopes; they are not universal field acceptance limits for every vessel or space. Compare the measured state with the actual approved design, specification, commissioning procedure or agreed diagnostic basis. Mark inaccessible or unverified branches rather than inferring their performance.
| System / branch | Target / basis | Measured state | Instrument / method | Correction / uncertainty | Adjacent effect | Commissioning status |
|---|---|---|---|---|---|---|
| COM-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| COM-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| COM-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Quantify comparability before interpreting improvement.
Match or document space, point and height, occupancy and activity, HVAC mode and setpoints, door and hatch state, fan and damper configuration, outdoor reference, wind and nearby exhaust conditions, cleaning, coating, cargo or maintenance activity, stabilisation time, sampling duration, instrument settings, laboratory method and custody. Align events in time so intermittent sources are not hidden by averaging.
Repeat the metric that supported the finding, not merely the easiest spot reading. If a system adjustment is the action, verify both the affected airflow or pressure path and the decision-relevant IAQ response where required. A lower carbon-dioxide value under reduced occupancy, a lower particle value after temporary cleaning or a higher flow with different fan duty may not verify the permanent change.
| Item | Baseline state | Verification state | Condition difference | Measured change | Uncertainty / limitation | Decision impact |
|---|---|---|---|---|---|---|
| RET-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| RET-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| RET-03 | ___ | ___ | ___ | ___ | ___ | ___ |
State what is verified, conditional or still unresolved.
The close-out report should connect baseline, cause evidence, authorisation, installed configuration, commissioning result and matched verification. Include methods, instruments, calibration, laboratory and custody information, detection limits, operating and occupancy conditions, raw-file references, uncertainty or repeatability, deviations and limitations. Separate measured facts, engineering interpretation and acceptance decisions.
Classify every item as verified for the tested state, verified with limitation, partially verified, not verified, not tested, superseded or awaiting acceptance. Record residual risks, maintenance or monitoring needs and the follow-up owner. Vessel Doctor can document technical evidence but does not claim a health outcome or acceptance by class, flag, owner, yard or another party without a traceable decision.
| Finding / action | Verification state | Evidence reference | Residual limitation | Follow-up owner | Acceptance owner | Release revision |
|---|---|---|---|---|---|---|
| CLOSE-01 | ___ | ___ | ___ | ___ | ___ | ___ |
| CLOSE-02 | ___ | ___ | ___ | ___ | ___ | ___ |
| CLOSE-03 | ___ | ___ | ___ | ___ | ___ | ___ |
Confirm the governing edition and vessel basis.
- ISO 16000-1:2004, confirmed in 2024, supports purpose-led indoor-air sampling strategy.
- ISO 7547:2022 covers design conditions and calculation methods for ship accommodation air-conditioning and ventilation within its stated scope.
- ISO 8861:1998, confirmed in 2022 and currently under review, addresses design requirements and calculations for engine-room ventilation in diesel-engined ships.
- ISO 16000-40:2019 provides an indoor-air-quality management-system framework.
These sources do not create one universal pollutant limit, airflow criterion or approval route. Confirm the current contract, approved design, class and flag requirements, occupational basis, laboratory method and vessel-specific acceptance owner.
Send the released finding and executed change.
Provide the complaint and event timeline, baseline report, deck and ventilation drawings, applicable basis, approved instruction, installed configuration and required acceptance route so commissioning and matched verification can be scoped.
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