How to verify ventilation capacity in a TB-ML 3000 meeting booth

How to verify ventilation capacity in a TB-ML 3000 meeting booth

Does the TB-ML 3000 Multiple Person Meeting Booth deliver sufficient fresh air at its intended occupancy? Verifying ventilation capacity requires more than checking a fan’s rated airflow. It means confirming installed airflow, identifying the source of replacement air, and assessing performance with the door closed under realistic operating conditions. Airflow measurements and occupied CO₂ trends provide different pieces of evidence; neither should be interpreted without understanding the booth’s connection to the surrounding office.

No model-specific ventilation test report or airflow specification for the TB-ML 3000 is established here. Its capacity therefore needs to be verified from the supplier’s documentation and project measurements, not inferred from the model name or specifications for another booth.

Define the acceptance condition before testing

Start with intended occupancy, meeting duration, and the ventilation setting people will actually use. Maximum fan speed may produce an acceptable reading, but that result is of limited value if users lower the speed to hear remote participants. Record whether the project requires acceptable performance at normal speed, maximum speed, or an automatically controlled setting.

The applicable ventilation requirement should come from the project’s mechanical design and local requirements. ASHRAE Standard 62.1 or the EN 16798 series may be relevant references, depending on jurisdiction and specification. Confirm the adopted edition, occupancy classification, and calculation method with the responsible engineer. A generic air-change target is not a substitute for this review.

For plug-and-play acoustic enclosures—from single-person call hubs to multi-person boardrooms—the furniture installation and building ventilation design must be considered together. Similar modular construction may also serve airport changing lounges, private banking suites, or purification cabins, but those applications do not establish ventilation suitability for an office meeting booth. Each needs its own performance criteria.

Find out what the airflow number actually describes

Ask for an airflow-path drawing and the basis of the published capacity. A fan’s free-air rating excludes the resistance imposed by grilles, acoustic baffles, filters, and internal passages. Those components help a booth function as an acoustic enclosure, but they can reduce delivered airflow.

• Is the stated capacity a fan rating or a measurement of the assembled booth?
• Does “total airflow” mean supply, exhaust, internal recirculation, or a sum of several values?
• Were the door closed and all acoustic components installed during testing?
• Which speed, filter condition, and measurement method produced the result?
• Does replacement air come directly from outdoors or from the surrounding office?

The last distinction is critical. A booth drawing air from an open-plan office receives transfer air, not necessarily dedicated outdoor air. Its performance depends partly on the office HVAC system, surrounding occupancy, and local mixing. Moving more office air through the booth cannot compensate indefinitely for inadequate outdoor-air delivery to the host space.

A useful comparison is the TB-W Office Pod 1-2 Person, whose listed maximum total airflow is 180 m³/h and internal dimensions are 1.35 × 1.20 × 2.00 m. Those figures imply a nominal volume-to-flow time of approximately 65 seconds, whereas its separate exchange-time claim is 35 seconds. The definitions and test conditions need clarification. Neither figure establishes TB-ML 3000 performance, and a nominal exchange time does not mean every pocket of air has been replaced.

Measure the installed booth, not an exposed fan

Test after installation, with final furniture, seals, filters, and ventilation covers in place. Leave the surrounding HVAC operating normally. Check that walls, storage units, or ceiling features do not obstruct external openings, and keep the door closed during readings.

A calibrated flow hood can be useful where the opening geometry permits reliable capture. However, the hood itself may add enough resistance to alter a small fan’s output. Use an appropriate low-resistance arrangement or a validated correction method. Where a hood is unsuitable, a competent technician may use an anemometer traverse and a defensible effective-area calculation.

Do not multiply one high velocity reading at the centre of a grille by its gross dimensions. Louvres reduce free area, and discharge velocity may be uneven. Document the instrument, measurement locations, area assumptions, and uncertainty.

Measure each relevant inlet or outlet and calculate the total for that side of the airflow path. Do not add supply and exhaust together as though they were separate ventilation deliveries: they may represent the same air passing through the enclosure. A substantial imbalance warrants investigation of leakage paths, missed openings, or measurement error.

Convert airflow into useful evaluation figures

Two calculations help put measured airflow into context:

• Air changes per hour: measured airflow in m³/h divided by internal volume in m³.
• Flow per occupant: measured airflow in m³/h divided by 3.6, then divided by the number of occupants, giving L/s per person.

Label both figures accurately. If the measurement represents transfer air from the office, neither calculation turns it into an outdoor-air rate. A compact booth can show a high air-change rate while still having inadequate ventilation for its occupant load. Conversely, a satisfactory volumetric flow does not prove good distribution if air travels directly from inlet to outlet without adequately reaching seated occupants.

Use an occupied CO₂ test to check the operating picture

An occupied test helps reveal problems that an empty-booth airflow measurement may miss. Use calibrated CO₂ instruments to log conditions inside the booth and in the surrounding office simultaneously. If the assessment requires an outdoor reference, measure that separately rather than assuming a fixed background concentration.

Position the internal sensor near seated breathing height, away from direct exhalation and ventilation jets. Record occupancy, fan mode, door openings, HVAC operation, and temperature. Run the test for the intended meeting duration, without forcing occupants to remain in uncomfortable conditions simply to obtain a longer trace.

Interpret the pattern, not just the peak. A sustained rise inside while surrounding-office CO₂ remains relatively stable suggests inadequate effective exchange for that occupancy. If both rise together, investigate the host space as well. A short meeting may end before equilibrium; back-to-back meetings may begin before the booth has cleared.

CO₂ is supporting evidence of occupancy-related ventilation, not a complete indoor-air-quality certificate or a universal pass/fail threshold. Temperature also matters: adequate airflow may still leave occupants uncomfortable if replacement air is warm or internal heat loads are high.

Make the handover decision traceable

The acceptance record should identify the tested configuration, occupancy, measured airflow by operating mode, replacement-air source, instrument uncertainty, and occupied-test conditions. Include any dependence on building HVAC operating hours and any maintenance needed to preserve airflow.

If the TB-ML 3000 Multiple Person Meeting Booth only satisfies the agreed criteria at maximum speed, state that limitation explicitly. If outdoor-air provision remains unverified, keep that item open for the mechanical engineer. A defensible handover is a documented operating condition—not a fan rating presented as proof of fresh-air capacity.