How Facilities Teams Can Record Haze and Indoor PM2.5 Data Malaysia
How Facilities Teams Can Record Haze and Indoor PM2.5 Data Malaysia
During haze periods in Malaysia, checking a PM2.5 monitor once may show the current condition, but it does not explain how indoor air quality changes throughout the day.
A simple monitoring record helps facilities teams identify:
When indoor PM2.5 increases.
Which rooms are affected.
Whether outdoor haze is entering the building.
Whether an air purifier is reducing particle levels.
Whether doors, loading bays, or ventilation activities affect the readings.
Whether the same problem occurs on several days.
The record does not need to be complicated. The most important requirement is to use a consistent measurement method.
Why PM2.5 Records Are More Useful Than One Reading
Indoor PM2.5 can change because of:
Outdoor haze conditions.
Doors and windows opening.
Loading bay activities.
Vehicle movement.
Air conditioner operation.
Air purifier operation.
Filter condition.
Cleaning activities.
Smoking or combustion sources.
Changes in room occupancy and ventilation.
A high reading without any supporting information can be difficult to interpret. Recording the time, location, equipment status, and nearby activities gives the reading useful context.
What Information Should Be Recorded?
A practical indoor air quality record can include:
Record ItemInformation to EnterDateDate of measurementTimeTime the reading was takenLocationOffice, meeting room, guardhouse, classroom, warehouse, or cleaner roomPM2.5Reading shown by the monitorCO2Record if the selected monitor measures CO2TemperatureIndoor temperatureHumidityIndoor relative humidityDoor and window statusOpen, closed, or frequently openedAir conditionerOn or offAir purifierOn, off, or selected operating modeOutdoor conditionClear, moderate haze, heavy haze, or rainNearby activityTraffic, loading, cleaning, smoking, or cookingAction takenClosed door, started purifier, or changed locationFollow-up readingReading after the action
The measurement parameters available will depend on the selected air quality monitor.
Select Representative Monitoring Locations
Facilities teams should avoid taking every reading from one convenient desk.
Useful monitoring locations may include:
Main office.
Meeting room.
Reception area.
Guardhouse.
Warehouse office.
Production office.
Classroom or training room.
Loading bay entrance.
Cleaner indoor room.
Room with an air purifier.
Start with locations where people spend significant time or where outdoor air frequently enters the building.
For a factory in Selangor, for example, the facilities team may compare the main office, guardhouse, warehouse entrance, and a cleaner indoor room. This helps show whether the problem affects the whole building or only certain zones.
Keep the Monitor Position Consistent
Readings from different positions may not be directly comparable.
For routine recording, place the monitor:
At approximately breathing height.
Away from direct sunlight.
Away from rain and moisture.
Away from direct air conditioner airflow.
Away from the immediate outlet of an air purifier.
Away from walls or corners where air movement is limited.
On a stable surface.
In the normal occupied area.
If the monitor must be moved between locations, allow it time to respond to the new environment before recording the reading.
Use the same position whenever possible. For example, do not measure on a desk one day and directly beside an open window the next day if you want to compare trends.
Choose a Practical Monitoring Schedule
The correct checking frequency depends on the building and haze conditions.
A basic schedule may include:
Before Work Starts
Take a reference reading before most employees arrive and before doors begin opening frequently.
During the Morning
Check after staff arrival, delivery activity, or ventilation changes.
Around Midday
Record conditions after several hours of occupancy and air conditioner operation.
During the Afternoon
Check whether indoor PM2.5 has increased as outdoor haze or traffic conditions change.
Before Closing
Record the final condition and note whether the air purifier or ventilation system operated throughout the day.
Additional readings may be useful after a visible haze increase, heavy vehicle movement, cleaning activity, or a sudden monitor alarm.
Record Before and After Taking Action
Before and after measurements help facilities teams evaluate whether an action is working.
For example:
Record the indoor PM2.5 level.
Note that the door is frequently open.
Close the door when access is not required.
Operate the air purifier.
Keep other conditions as consistent as possible.
Record another reading later.
Compare the result.
Avoid judging performance from only a few minutes of operation. PM2.5 reduction depends on room size, air movement, particle entry, purifier capacity, filter condition, and other factors.
Compare Indoor and Outdoor Conditions Carefully
Outdoor air quality information can provide useful background, but a nearby official station may not represent the exact condition at the building.
Indoor PM2.5 may also differ from outdoor readings because of:
Building filtration.
Closed doors and windows.
Air leakage.
Local traffic.
Nearby smoke.
Loading activity.
Indoor particle sources.
Air purifier operation.
Facilities teams should record the available outdoor haze condition while relying on indoor measurements to understand the actual room environment.
PM2.5 and CO2 Should Be Interpreted Separately
If the selected Temtop air quality monitor measures both PM2.5 and CO2, the two readings should not be treated as the same problem.
PM2.5 helps indicate fine particle pollution.
CO2 can help facilities teams understand the effect of occupancy and ventilation, but it does not represent all indoor pollutants.
During haze, closing doors and windows may help reduce the entry of particles. However, CO2 may rise in a crowded room with insufficient ventilation.
Recording both readings helps the facilities team understand this trade-off and review ventilation and filtration separately.
Look for Patterns Instead of Isolated Numbers
After several days of monitoring, review the records for repeated patterns.
Ask:
Does PM2.5 increase during morning traffic?
Is the guardhouse consistently higher than the office?
Does the loading bay affect nearby rooms?
Does PM2.5 fall when the air purifier operates?
Does the reading increase when the door is left open?
Is one floor or room consistently worse?
Does CO2 rise in crowded meeting rooms?
Does indoor PM2.5 remain high after outdoor haze improves?
Repeated patterns are more useful for planning improvements than one unusual reading.
Common Recording Mistakes
Avoid these common mistakes:
Recording only the PM2.5 number without the time and location.
Changing the monitor position for every reading.
Placing the monitor directly beside a purifier outlet.
Comparing readings from different instruments without checking their consistency.
Ignoring open doors, cleaning, smoke, or vehicle activity.
Assuming that a stable display always means the room is safe.
Treating a PM2.5 monitor as a detector for every gas.
Using an indoor air quality monitor in rain or unsuitable industrial conditions.
Making major decisions from only one short measurement.
A monitor provides measurement information. It does not replace a complete workplace risk assessment or a gas detector designed for a specific hazard.
Portable Monitor or Continuous Data Logging?
A portable air quality monitor is suitable when facilities personnel need to compare several rooms using one instrument.
A monitor with data logging may be more suitable when the team needs to observe:
Overnight changes.
Full-day trends.
Air purifier performance.
Repeated pollution entry.
Conditions before employees arrive.
Changes during different work shifts.
The best choice depends on the number of monitoring points, required parameters, recording period, and how the data will be used.
Selecting a Temtop Monitor for Facilities Work
Before choosing a Temtop air quality monitor, consider:
Required measurements such as PM2.5, CO2, temperature, or humidity.
Portable checking or continuous monitoring.
Display and alarm requirements.
Data logging requirements.
Number of rooms.
Monitoring duration.
Indoor operating environment.
Staff experience and reporting needs.
Product functions vary by model. The selected monitor should match the intended application rather than simply having the largest number of displayed parameters.
Build a Repeatable Indoor Air Quality Routine
A clear recording method turns individual PM2.5 readings into practical facilities information.
With consistent locations, measurement times, and activity notes, teams can better evaluate haze entry, air purifier operation, room differences, and recurring building problems.
For assistance selecting a Temtop PM2.5 or indoor air quality monitor for offices, factories, warehouses, classrooms, clinics, or commercial buildings in Malaysia, contact MTM Precision.
MTM Precision Sdn Bhd
Showroom and Service Centre: No. 29-1 and 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my
07 Oct 2026
