When discussing environmental monitoring in data centres, most conversations focus on just two metrics: temperature and humidity.
These factors matter because excess heat jeopardises equipment stability, and humidity swings—whether too high or too low—create problems such as condensation or electrostatic discharge.
But those numbers reveal only part of the picture. The airflow inside a data centre carries dust and other particulates, and carbon dioxide (CO²) levels give insight into how well spaces ventilate, especially where staff work.
Consequently, an effective monitoring strategy must go beyond merely checking if the room stays cool. It should enable operators to see the broader environment surrounding their critical hardware, helping them detect particulate buildup, adjust ventilation early, and maintain overall system health.
Temperature and Humidity Remain the Starting Point
Temperature and humidity monitoring are essential to any data centre environmental strategy, but a single room level reading often fails to reflect conditions across the whole data hall. Subsequently, different racks generate distinct heat loads, and airflow can vary between aisles and individual cabinets. Because of this, an acceptable average temperature may hide a developing hotspot around a specific piece of equipment.
Humidity presents its own challenges: excess moisture raises the risk of condensation and corrosion, while overly dry air increases the chance of electrostatic discharge. As a result, distributed environmental sensors give operators a much clearer, real time view of what is actually happening around the IT equipment.
Even when temperature and humidity appear normal, other environmental factors—such as particulate levels, or CO² levels can still shift. Therefore, continuous, multi parameter monitoring remains crucial.
What Temperature and Humidity Cannot Tell You
Imagine a data hall where temperature and humidity readings always stay within their expected limits. Does that guarantee a healthy environment? Not necessarily.
Construction elsewhere in the building can stir up extra airborne particles. Likewise, a damaged or overloaded filter may let contaminants slip into the hall. Furthermore, routine maintenance can kick up settled dust, while unboxing equipment in the white space can expel fibres. Even changes in how many people occupy the space or how the ventilation system performs can degrade air quality without causing an obvious temperature shift.
Standard temperature and humidity sensors won’t flag any of these issues. Therefore, this creates a gap in environmental monitoring.
As a result, organisations that want clearer insight should evaluate air quality — particles, gases, and pollutants — in addition to tracking temperature and moisture.
Data Centre Air Quality Monitoring
Why Air Particle Monitoring Matters
Data centres rely on large volumes of flowing cold air to keep equipment cool. However, that same airflow can carry unwanted particles inside. Dust and other particulates slip in through ventilation shafts, during routine maintenance, while construction work proceeds, or simply as people and equipment move around.
As a result, these contaminants settle on filters, fans and electronic parts, restricting airflow, lowering cooling efficiency and raising the risk of equipment failure.
Because many airborne particles are microscopic, visual checks alone cannot reveal the full extent of the buildup. Consequently, adding particle monitoring gives operators an extra, quantitative view of air quality.
For example, the ADS iSensor Particle Sensor measures particulate matter at PM1.0, PM2.5 and PM10 levels. Rather than waiting until contamination becomes visible, operators can monitor particle levels and identify changes as they happen.
What Does This Mean?
Particle monitoring now serves as more than just an alarm system.
Historical data can show, for example, a spike in airborne particles after maintenance tasks, or it can reveal how changes to ventilation affect particle levels. Likewise, a sudden rise may trigger a check of filter efficiency.
As a result, operators shift from asking only, “Is the data centre overheating?” to asking, “What is changing in the environment?” This broader question yields far more actionable insight.
CO² Adds Another Dimension to Environmental Monitoring
Monitoring carbon dioxide offers a unique viewpoint.
IT equipment does not generate large amounts of CO² just by running. However, people do. Consequently, rising or falling CO² levels reveal how many people occupy a room and how effectively the ventilation works.
This matters especially when engineers, contractors, or maintenance crews work inside data halls, communications rooms, or other technical spaces. If CO² levels rise, the data helps identify areas where ventilation fails to match occupancy.
Importantly, CO² levels cannot be used as a direct measurement of airborne infection risk. Instead, CO² serves as an indicator of ventilation conditions and the share of rebreathed air in an occupied space. This distinction matters.
Nevertheless, combining CO² data with other information yields a deeper understanding of the conditions experienced by people in the facility.
From CO² Monitoring to Infection-Risk Assessment
The ADS CO² sensor extends this capability further.
In addition to measuring CO², temperature, and humidity, the solution actively incorporates environmental data into a Wells Riley model to estimate the probability of airborne infection transmission in an occupied space.
The Wells Riley approach evaluates key factors such as ventilation rate, exposure time, and occupancy conditions. Importantly, a CO² sensor does not detect viruses or confirm the presence of an infected individual.
Instead, operators treat CO² levels as one input when assessing the conditions that could influence airborne transmission risk. This distinction adds value because it moves beyond a simple good or bad carbon dioxide reading; operators can analyse the data to decide whether they need to take further action.
For example, if a risk assessment rises during scheduled maintenance, teams can immediately examine ventilation settings, occupancy levels, or work arrangements to mitigate potential spread.
Protecting People as Well as Equipment
Traditionally, operators have focused environmental monitoring on protecting critical IT infrastructure, and that remains essential. However, a data centre is also a workplace; engineers enter the halls to install equipment, perform maintenance, investigate faults, and run scheduled tests, while contractors and other staff may spend long periods inside technical areas.
Consequently, environmental monitoring serves two purposes. Temperature, humidity, and particle sensors reveal conditions that could threaten equipment reliability and cooling performance. Meanwhile, CO² sensors give extra insight into ventilation and the air quality of the occupied space.
As a result, this broader approach moves monitoring beyond simply safeguarding servers. It helps organisations understand the environment that surrounds both equipment and the people who work with it.
Bringing Environmental Data Together
Of course, gathering extra measurements adds value only when operators can interpret the data effectively. When each sensor uses its own interface, the collection itself turns into another monitoring headache—so integrating the devices becomes essential.
The ADS iSensor Controller offers a unified platform that gathers readings from multiple environmental sensors within the data centre. One controller handles up to 24 sensors. Generally, these would be temperature / humidity sensors. However, you can attach optional sensors for carbon dioxide, particulate matter, and volt free contacts (VFC).
Through SNMP, this information can also feed into wider management platforms, including DCIM and BMS solutions.
When integrating the iSensor Controller with Sensorium™ DCIM, environmental data merges into a holistic picture of facility performance. Rather than viewing temperature, humidity, particle counts, and CO² as isolated numbers, operators now see them as interconnected clues about the same surroundings.
This contextual view makes abnormal conditions stand out and simplifies troubleshooting.
From Basic Monitoring to Environmental Intelligence
The goal is not to gather data just because a sensor can record it. Furthermore, each additional monitoring point should answer a specific operational question.
- Temperature: Does the equipment risk overheating?
- Humidity: Is the air becoming damp enough to cause condensation, corrosion, or static discharge?
- Particle levels: Are airborne contaminants increasing, or is filter performance declining?
- CO²: Are ventilation and occupancy affecting indoor air quality?
- Infection risk assessment: Could the current space conditions raise the chance of airborne transmission?
Together, these metrics provide a far richer picture than temperature and humidity alone.
Moreover, continuous monitoring builds a historical record that operators can use to spot trends, compare conditions before and after changes, and investigate what happened around an environmental event.
As a result, environmental monitoring shifts from merely watching isolated numbers to understanding how the data centre environment behaves.
A Wider View of the Data Centre Environment
Temperature and humidity remain core metrics for any data centre environment. Yet they should not be the sole determinants of an environmental monitoring strategy.
Airborne particles can expose contamination that temperature sensors miss, while CO² levels reveal how well spaces are ventilated and occupied. Moreover, environmental data feed models that estimate airborne infection risks for staff on site.
By combining these measurements, operators obtain a fuller view of the conditions inside the facility.
Effective monitoring does more than report whether a room is hot or humid.
It should help you understand what is happening in the environment — and give you the information needed to act when something changes.