Air quality sensors: what they can and can't tell you

Commonly particulates, carbon dioxide, humidity, temperature, and sometimes gases like VOCs. Sensors measure particular aspects of air quality: particulates (fine particles - PM2.5 and PM10 - from cooking and other sources); carbon dioxide (CO2, which builds up from people breathing and indicates how well a space is ventilated with fresh air - high CO2 means stuffy, under-ventilated air); humidity and temperature; and sometimes volatile organic compounds (VOCs) or specific gases. They report these as readings, often continuously, and can alert you or log the data when a reading is poor or crosses a threshold. This is genuinely useful because air quality is largely invisible (you cannot see CO2 or fine particulates), so a sensor makes it visible and measurable - telling you when the air is poor, when it worsens (for example during busy cooking), and how conditions change over time. So sensors measure aspects of the air and flag when it is poor, giving information and early warning. So they can measure particulates, CO2, humidity, temperature and some gases. This is general commentary.

Why the air is poor, or how to fix it - and they don't improve the air themselves. A sensor tells you the air is poor (a reading), but not the specific cause: high CO2 tells you the space is under-ventilated with fresh air, but not exactly why or what to change; high particulates tell you there are particles, but not their precise source or solution. So the sensor identifies that there is a problem and roughly what kind, but diagnosing the cause needs judgement and investigation beyond the sensor. More fundamentally, a sensor does not improve the air - it monitors, it does not ventilate or clean. The air does not get better because it is measured; a sensor showing poor air, with nothing done, leaves the air just as poor. So a sensor is not a solution - it is an instrument telling you there is a problem to solve. Relying on it alone does nothing to improve the air; the improvement comes from acting on what it shows. So sensors can't tell you why the air is poor or how to fix it, and don't fix it themselves. This is general commentary.

Act on the ventilation and extraction - because that is what actually clears and refreshes the air, not the sensor. A commercial kitchen generates poor-air contributors (particulates and fumes from cooking, heat, humidity, cooking gases, CO2 from people), and the way to clear them is ventilation and extraction: the extraction removes the cooking-generated pollutants, heat and humidity at source, and the ventilation brings in fresh air to replace what is extracted and dilute the CO2. So if a sensor shows poor kitchen air, the fix lies in ensuring the extraction is effectively removing the cooking pollutants, heat and humidity, and that there is adequate fresh-air supply. A common underlying cause of poor kitchen air is a grease-loaded, underperforming extraction - so checking and cleaning the extraction (restoring its performance) is often a direct fix. The sensor tells you there is a problem; the ventilation and extraction (kept clean and working) are what solve it. So act on the ventilation and extraction, including cleaning the extraction, rather than relying on the sensor. This is general commentary.

Yes - the extraction is central to kitchen air quality, because it removes the cooking-generated pollutants, heat and humidity at source. A commercial kitchen's air quality depends heavily on the extraction: it draws off the particulates, fumes, grease-laden vapour, heat and humidity from the cooking, keeping them out of the air people breathe. So how well the extraction works directly determines the air quality - an effective extraction clears the cooking pollutants and keeps the air good, while a poor or underperforming one leaves them in the air (which a sensor would show as poor readings). Crucially, the extraction's performance depends on it being kept clean: a grease-loaded, neglected extraction (clogged filters, grease-laden ductwork, a straining fan) extracts less effectively, clearing the air less well, while a clean, well-maintained one extracts effectively. So the extraction strongly affects kitchen air quality, and keeping it clean and working is key to good air. This is why a clean, working extraction is the real fix for the poor air a sensor measures. So yes - the extraction is central to kitchen air quality. This is general commentary.

Yes - as a useful monitoring and early-warning tool, provided they are seen as an instrument, not a solution. Sensors are worth having for what they do: making largely-invisible air quality visible and measurable, giving early warning when the air is poor, monitoring conditions over time, providing data (for managing ventilation or demonstrating conditions), and confirming improvements after a fix. That is genuinely valuable - you cannot manage what you cannot see, and sensors let you see the air. But they should be kept in perspective: a sensor tells you the air is poor, not why or how to fix it, and it does not improve the air itself. So a sensor is a useful part of managing air quality, but not the whole of it - the improvement comes from acting on what it shows (the ventilation and extraction). Used well (to flag problems and verify fixes, with action taken on the ventilation and extraction), sensors are worthwhile; relied on alone (installed and watched, with nothing done), they achieve nothing for the air. So yes - sensors are worth having as a monitoring tool, alongside acting on the ventilation and extraction. This is general commentary.

By restoring the extraction's ability to clear the cooking pollutants, heat and humidity - genuinely improving the air the sensor reads. The extraction's ability to remove the cooking-generated pollutants, heat and humidity depends on it working properly, which depends heavily on it being kept clean. A grease-loaded, neglected extraction (clogged filters, grease-laden ductwork, a straining fan) extracts less effectively, so it clears the cooking pollutants, heat and humidity less well, leaving the air poorer - which a sensor shows as worse readings. Cleaning the extraction (removing the built-up grease from the filters, ductwork and fan) restores its extraction performance, so it clears the air effectively again - genuinely improving the air quality (which the sensor would then show as improved readings). So if a sensor is flagging poor air, a grease-loaded, underperforming extraction is a common underlying cause, and cleaning it is a direct way to improve the air. This is the real fix the sensor points toward: not the sensor itself, but the clean, working extraction that actually clears the air. So cleaning the extraction improves the air by restoring its clearing performance. This is general commentary.