How to Monitor PM2.5 in Classrooms and Schools During Haze Malaysia

How to Monitor PM2.5 in Classrooms and Schools During Haze Malaysia

Haze is an important environmental concern for schools, kindergartens, tuition centres and educational institutions throughout Malaysia.

During periods of elevated outdoor air pollution, school administrators, teachers and parents may become concerned about the air quality inside classrooms.

An important question is:

Is the air inside a classroom cleaner than the air outside during haze?

The answer depends on several factors, including outdoor pollution, classroom ventilation, building air leakage, indoor particle sources and air filtration.

Closing classroom windows may reduce the entry of outdoor haze particles, but it does not automatically guarantee low indoor PM2.5 concentrations.

A portable PM2.5 air quality monitor, such as the Temtop S1 Up, can help schools observe changes in indoor particulate concentrations and identify situations that may require further investigation.

This guide explains how to monitor classroom PM2.5 during haze, where to position an air quality monitor, how to interpret readings and how to evaluate air purifier operation.

MTM Precision Sdn Bhd supplies portable air quality monitoring instruments in Malaysia for schools, offices, homes and general indoor environmental applications.

1. Why Is Classroom Air Quality Important During Haze?

Students and teachers may spend several hours each day inside classrooms.

During haze episodes, outdoor fine particulate pollution can enter school buildings through windows, doors, ventilation systems and other openings.

Children are among the populations for whom reducing exposure to air pollution is particularly important.

Fine particulate pollution is associated with adverse respiratory and cardiovascular health effects.

Schools may need to consider air quality in:

Primary school classrooms

Secondary school classrooms

Kindergarten rooms

Preschool activity areas

Tuition centres

School libraries

Computer laboratories

Indoor assembly halls

Staff offices

School administrative areas

Monitoring classroom PM2.5 can support environmental awareness and help schools investigate particulate pollution, but it does not replace official health or school safety guidance.

2. What Is PM2.5?

PM2.5 refers to airborne particles with an aerodynamic diameter of 2.5 micrometres or smaller.

These particles may originate from:

Forest fires and open burning

Vehicle exhaust

Industrial combustion

Outdoor haze

Cigarette smoke

Cooking activities

Other combustion sources

PM2.5 concentrations are generally expressed in micrograms per cubic metre (µg/m³).

Because these particles are extremely small, they cannot reliably be identified through visual observation alone.

A classroom may appear clean while still containing elevated concentrations of airborne fine particles.

A PM2.5 monitor provides information about fine particulate concentrations rather than the complete chemical composition of classroom air.

3. How Can Haze Enter a Classroom?

Outdoor haze particles may enter classrooms through several pathways.

Open Windows

Naturally ventilated classrooms may receive outdoor air directly through open windows.

Open Doors

Students and teachers entering or leaving the room can allow air exchange with corridors or outdoor areas.

Mechanical Ventilation

Ventilation systems may introduce outdoor air, depending on their filtration arrangements.

Building Air Leakage

Particles may enter through gaps around windows, doors and other building openings.

Connected Indoor Spaces

Particles can move between classrooms, corridors and shared spaces.

The amount of outdoor PM2.5 entering a classroom depends on building design, ventilation, filtration and environmental conditions.

Indoor PM2.5 should not automatically be assumed to match the outdoor pollution level.

4. Introducing Temtop S1 Up for Classroom PM2.5 Monitoring

The Temtop S1 Up Air Quality Monitor is a compact portable instrument suitable for general indoor particulate observations.

Its PM2.5 monitoring capability allows users to observe changes in fine particle concentrations.

Potential educational applications include:

Classroom PM2.5 monitoring

Kindergarten indoor particulate observation

School library air quality checks

Tuition centre monitoring

Haze-related indoor air quality observation

Air purifier performance comparison

Preliminary investigation of outdoor particle infiltration

The instrument may be moved between different rooms for spot checks.

However, measurements taken at different times may be affected by changing conditions.

For exact measurement range, accuracy, power supply and additional functions, refer to the latest Temtop S1 Up manufacturer specifications.

The instrument should not be assumed to measure CO2, ozone or other gases unless those capabilities are specifically documented.

5. How to Monitor PM2.5 in a Classroom During Haze

A consistent monitoring procedure can help schools obtain useful particulate observations.

Step 1 - Select the Classroom

Identify the classroom or indoor area to be monitored.

Record basic information such as:

Classroom dimensions

Number of occupants

Window positions

Door positions

Air-conditioning operation

Ventilation arrangement

Air purifier operation

Nearby outdoor pollution sources

Step 2 - Position the PM2.5 Monitor

Place the Temtop S1 Up in a representative occupied area.

Avoid direct air-conditioning outlets, air purifier discharges and obvious local particle sources.

Ensure the instrument is placed securely where students cannot accidentally knock it over or interfere with its operation.

Step 3 - Allow Readings to Stabilise

Operate the instrument according to the manufacturer's instructions.

Allow sufficient time for readings to stabilise.

Step 4 - Record the Initial PM2.5

Document the concentration in µg/m³.

Step 5 - Record Environmental Conditions

Note whether windows and doors are open, whether air purifiers are operating and whether outdoor haze is present.

Step 6 - Repeat Measurements

Record readings at consistent intervals.

Step 7 - Investigate Changes

If PM2.5 increases, consider possible outdoor particle infiltration or indoor pollution sources.

Repeated measurements under documented conditions are more useful than a single isolated reading.

6. Where Should You Place a PM2.5 Monitor in a Classroom?

Monitor placement affects how representative the reading may be.

Monitoring locationPurposeCentral classroom areaObserve general indoor particulate conditionsStudent seating areaObserve PM2.5 near occupied locationsTeacher workstationObserve conditions near teaching activitiesNear classroom entranceInvestigate particle entry from corridorsNear windowsInvestigate outdoor haze infiltrationAway from purifier outletObserve room air rather than only freshly filtered air

For general classroom monitoring, select a representative occupied location and follow the manufacturer's placement instructions.

Avoid blocking sensor openings.

Do not position the instrument where water, condensation or accidental impact may affect operation.

Use consistent monitoring locations when comparing measurements over time.

7. Example of Classroom PM2.5 Monitoring During Haze

The following readings are hypothetical examples provided only to demonstrate a monitoring record.

They are not actual Temtop S1 Up measurements.

TimeExample PM2.5Observation8:00 AM38 µg/m³Before class begins9:00 AM44 µg/m³Classroom occupied10:00 AM51 µg/m³Windows opened11:00 AM36 µg/m³Windows closed, purifier operating12:00 PM25 µg/m³Continued purifier operation

These figures illustrate how particulate concentrations might change during normal classroom activities.

Actual measurements depend on:

Outdoor PM2.5

Ventilation

Classroom occupancy

Air purifier capacity

Window and door openings

Indoor particle sources

Sensor characteristics

A change in PM2.5 does not prove that one specific activity caused the entire increase or decrease.

8. Should Schools Close Classroom Windows During Haze?

During periods of elevated outdoor particulate pollution, reducing unnecessary entry of polluted outdoor air may help limit indoor PM2.5.

However, ventilation remains important.

Closing windows without adequate alternative ventilation can allow certain indoor-generated pollutants to accumulate.

For example, carbon dioxide concentrations may rise in heavily occupied classrooms with insufficient fresh-air exchange.

A PM2.5 monitor does not measure ventilation adequacy.

Schools should consider:

Official outdoor air quality information

Building ventilation design

Availability of filtered fresh air

Classroom occupancy

Indoor pollution sources

Air purifier capacity

Applicable education and health authority guidance

Schools should not completely disable essential ventilation simply to reduce PM2.5 readings.

A properly designed and maintained filtered ventilation system may help balance particulate control with fresh-air requirements.

9. Can Air Purifiers Reduce Classroom PM2.5?

A suitable air purifier equipped with effective particulate filtration can help reduce airborne PM2.5.

However, performance depends on:

Verified particle Clean Air Delivery Rate (CADR)

Classroom volume

Airflow distribution

Filter condition

Fan speed

Outdoor pollution infiltration

Ongoing indoor particle sources

A small desktop purifier may not provide sufficient clean-air delivery for a large classroom.

Schools should select air purifiers based on room dimensions and verified performance specifications.

Air purifier selection should consider room volume and clean-air delivery rather than relying only on product marketing claims.

10. How to Check Classroom Air Purifier Performance Using Temtop S1 Up

A portable PM2.5 monitor can help schools observe particulate concentration changes while an air purifier operates.

Step 1 - Record the Initial PM2.5

Place the monitor in a representative occupied location.

Allow readings to stabilise.

Step 2 - Operate the Air Purifier

Switch on the purifier according to the manufacturer's instructions.

Use a consistent operating setting.

Step 3 - Maintain Comparable Conditions

Avoid unnecessary changes in windows, doors and other conditions during the observation.

Do not deliberately introduce smoke or harmful particles for testing.

Step 4 - Record PM2.5 Over Time

For example:

Monitoring timeExample PM2.5Before purifier operation55 µg/m³After 15 minutes43 µg/m³After 30 minutes34 µg/m³After 45 minutes27 µg/m³After 60 minutes21 µg/m³

These are hypothetical figures, not actual product performance results.

Step 5 - Interpret the Trend

A decreasing PM2.5 concentration may indicate improving particulate conditions at the monitoring location.

However, changes may also result from ventilation, particle deposition and variations in pollution sources.

A portable PM2.5 monitor cannot independently certify HEPA filter efficiency or CADR.

11. How Many Air Purifiers Does a Classroom Need?

The required number of air purifiers depends on several factors.

These include:

Classroom floor area

Ceiling height

Room volume

Air purifier CADR

Ventilation arrangement

Outdoor pollution infiltration

Airflow distribution

Indoor particle sources

For example, consider a hypothetical classroom measuring:

Length: 8 metres

Width: 7 metres

Ceiling height: 3 metres

The room volume is:

8 × 7 × 3 = 168 m³

If one purifier has a verified particle CADR of 300 m³/h, its nominal clean-air delivery relative to room volume is:

300 ÷ 168 = approximately 1.8 equivalent air changes per hour

This is a simplified calculation.

It does not guarantee actual classroom air quality or establish whether the purifier arrangement is sufficient.

Other ventilation and filtration systems may contribute additional clean-air delivery.

For classroom purifier selection, schools should evaluate total clean-air delivery and airflow distribution using appropriate technical guidance.

12. PM2.5 vs CO2 Monitoring in Classrooms

PM2.5 and CO2 measure different aspects of indoor air quality.

PM2.5 Monitoring

Provides information about fine airborne particulate concentrations.

It is particularly relevant to haze, smoke particles and general particulate pollution.

CO2 Monitoring

Provides information about carbon dioxide concentration.

CO2 monitoring can support ventilation assessment in occupied classrooms when interpreted appropriately.

A classroom may have low PM2.5 but elevated CO2 if ventilation is inadequate.

Similarly, a classroom may have acceptable CO2 levels but elevated PM2.5 because polluted outdoor air is entering.

ParameterMain monitoring purposePM2.5Fine particulate pollutionCO2Ventilation-related assessmentTemperatureThermal conditionsRelative humidityMoisture conditionsOzoneSpecialised gaseous pollutant monitoring

A PM2.5 monitor should not be treated as a substitute for a dedicated CO2 monitor.

13. Understanding Malaysia API During Haze

Malaysia's official Air Pollutant Index (API) is used to report outdoor air quality.

The API provides information that can support public health and environmental decisions.

However, API is not the same as indoor PM2.5 concentration.

PM2.5 concentration is generally expressed in µg/m³.

API is a calculated index based on the official methodology.

Schools should refer to official Department of Environment information and relevant Ministry of Education or health authority instructions when making decisions about school activities during haze.

A portable indoor PM2.5 monitor does not replace official API reporting.

School closure decisions, outdoor activity restrictions and other official measures should follow applicable Malaysian authority guidance, not an unofficial indoor sensor threshold.

14. Understanding PM2.5 Readings in Classrooms

The World Health Organization's 2021 PM2.5 air quality guideline values include:

Averaging periodWHO guidelineAnnual average5 µg/m³24-hour average15 µg/m³

These are health-based guidelines for the specified averaging periods.

They are not instantaneous classroom safety thresholds.

For example, a single reading of 25 µg/m³ cannot establish the classroom's 24-hour average.

Similarly, a low PM2.5 reading does not confirm that ventilation is adequate or that all other pollutants are absent.

Schools should interpret PM2.5 readings according to the instrument's limitations and the relevant averaging period.

15. Practical Classroom Haze Monitoring Schedule

A school may adopt a simple particulate monitoring routine.

Monitoring periodSuggested activityBefore school beginsRecord initial classroom PM2.5Morning sessionObserve occupied classroom conditionsAfter recessCheck for changes after door and window useAfternoon sessionRecord particulate trendsAfter purifier adjustmentObserve subsequent PM2.5 changesEnd of school dayReview and document measurements

The appropriate frequency depends on the monitoring objective and available equipment.

A portable monitor without confirmed data logging capability may require manual recording.

Do not assume that every Temtop S1 Up version provides automatic data logging or remote monitoring without checking the manufacturer's specifications.

16. Common Mistakes in School PM2.5 Monitoring

Mistake 1 - Using Outdoor API as an Indoor PM2.5 Reading

Outdoor API and indoor PM2.5 are different indicators.

Solution: Record each measurement using the correct units and source.

Mistake 2 - Positioning the Monitor Beside an Air Purifier Outlet

This may not represent particulate conditions throughout the classroom.

Solution: Use a representative occupied location.

Mistake 3 - Closing All Windows Without Considering Ventilation

Insufficient fresh-air exchange may allow other pollutants to accumulate.

Solution: Maintain appropriate ventilation and follow building guidance.

Mistake 4 - Assuming One Reading Represents the Entire School

PM2.5 may vary between classrooms and buildings.

Solution: Consider multiple monitoring locations.

Mistake 5 - Assuming Low PM2.5 Means All Pollutants Are Absent

PM2.5 sensors do not measure every gas or chemical.

Solution: Use additional instruments when other pollutants require assessment.

Mistake 6 - Using Consumer Monitors for Formal Compliance Certification

General-purpose portable monitors may not meet reference measurement requirements.

Solution: Use appropriate professional methods for formal assessments.

Mistake 7 - Making School Closure Decisions From a Single Indoor Reading

A single indoor measurement is not an official basis for school closure.

Solution: Follow current instructions from Malaysian education, environmental and health authorities.

17. Classroom PM2.5 Monitoring Checklist

CheckpointRecommended actionOutdoor hazeReview official API informationClassroom PM2.5Record concentration in µg/m³Monitor positionUse a representative occupied locationWindows and doorsDocument opening conditionsVentilationMaintain appropriate fresh-air provisionAir purifierCheck capacity, placement and filter conditionOccupancyRecord relevant classroom conditionsMonitoring intervalsUse consistent timesUnexpected PM2.5 increasesInvestigate possible particle sourcesInstrument maintenanceFollow manufacturer instructionsOfficial school measuresFollow relevant authority guidance

This checklist supports general environmental observations rather than formal school safety certification.

18. Frequently Asked Questions

Can haze enter a classroom when windows are closed?

Yes. Fine particles may enter through ventilation systems, door openings and building leakage.

Can Temtop S1 Up monitor classroom PM2.5?

Yes. It can be used for general indoor particulate observations according to its supported measurement functions.

Is one Temtop S1 Up enough for an entire school?

One instrument may be useful for preliminary spot checks, but it cannot monitor multiple classrooms simultaneously.

Should schools close classroom windows during haze?

Reducing unnecessary entry of polluted outdoor air may help, but appropriate ventilation must be maintained. Schools should follow relevant official guidance.

Can air purifiers reduce classroom PM2.5?

Suitable air purifiers with effective particulate filtration can help reduce airborne particles. Results depend on capacity, placement and operating conditions.

Can Temtop S1 Up measure CO2?

Customers should verify the exact manufacturer's specifications. PM2.5 monitoring does not imply CO2 measurement capability.

Can Temtop S1 Up measure ozone?

A PM2.5 sensor cannot measure ozone. Dedicated ozone measurement capability is required.

Can a PM2.5 monitor determine whether a school should close?

No. School closure and activity decisions should follow applicable Malaysian authority instructions.

Is low PM2.5 enough to confirm classroom air is safe?

No. PM2.5 is only one aspect of indoor air quality. Ventilation and other pollutants may also require attention.

Where can schools buy a PM2.5 monitor in Malaysia?

Educational institutions can contact MTM Precision Sdn Bhd in Puchong, Selangor, for pricing and stock availability.

19. Buy Temtop S1 Up PM2.5 Monitor for Schools Malaysia

MTM Precision Sdn Bhd supplies portable air quality monitoring instruments for educational institutions, homes, offices and commercial applications throughout Malaysia.

The Temtop S1 Up Air Quality Monitor is an option for schools seeking a convenient instrument for general classroom PM2.5 monitoring.

Potential applications include:

Primary school classroom monitoring

Secondary school classroom monitoring

Kindergarten indoor air quality observation

Tuition centre PM2.5 checks

School library particulate monitoring

Haze-related indoor air quality monitoring

Classroom air purifier performance observation

Customers may contact MTM Precision for:

Temtop S1 Up pricing

Current stock availability

Product specifications

School and classroom monitoring applications

Portable air quality monitor comparisons

General product selection assistance

MTM Precision serves customers throughout Selangor, Kuala Lumpur, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kelantan, Terengganu, Kedah, Perlis, Sabah and Sarawak.

Contact MTM Precision Sdn Bhd

Showroom & Service Centre

No. 29-1 & 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

Looking for a Classroom PM2.5 Monitor in Malaysia?

Contact MTM Precision for Temtop S1 Up pricing, stock availability and assistance selecting a suitable portable air quality monitoring instrument.

Schools and tuition centres may send us their classroom dimensions, ventilation arrangement or monitoring requirements through WhatsApp for an initial product recommendation.

Conclusion

During haze episodes in Malaysia, outdoor fine particles may enter classrooms through windows, doors, ventilation systems and building leakage.

Monitoring indoor PM2.5 can help schools observe particulate conditions and identify situations requiring further investigation.

The Temtop S1 Up Air Quality Monitor provides a convenient option for general classroom PM2.5 observations.

However, portable PM2.5 monitoring does not replace official outdoor API information, adequate ventilation, professional indoor air quality assessment or applicable school safety instructions.

A practical classroom haze management approach combines official air quality guidance, appropriate ventilation, effective particulate filtration, pollution source control and consistent indoor PM2.5 monitoring.

For Temtop S1 Up Malaysia and classroom PM2.5 monitoring enquiries, contact MTM Precision Sdn Bhd in Puchong, Selangor.