How to Monitor Indoor Air Quality During Haze Malaysia

How to Monitor Indoor Air Quality During Haze Malaysia

When haze affects Malaysia, many people immediately check the outdoor air quality.

But there is another important question:

What is happening inside your home, office or classroom?

During haze, people commonly:

Close windows.

Close doors.

Switch on air conditioning.

Operate air purifiers.

Spend more time indoors.

These actions may help reduce exposure to outdoor particulate pollution, but indoor air quality is not determined by PM2.5 alone.

When a room remains closed and occupied for many hours, CO2 can also change.

This is why indoor haze monitoring can benefit from looking at several parameters rather than relying on one air-quality number.

What Should You Monitor During Haze?

For many indoor applications, useful parameters can include:

PM2.5

CO2

Temperature

Humidity

and, depending on the application:

TVOC

Each parameter answers a different question.

PM2.5: The Main Haze-Related Measurement

PM2.5 is one of the most important measurements when investigating particulate pollution.

During haze, outdoor fine particles may enter indoor spaces through:

Open windows.

Open doors.

Building leakage.

Ventilation systems.

People moving between indoor and outdoor areas.

Other air-exchange pathways.

Indoor PM2.5 monitoring helps you understand the actual condition inside the space rather than assuming indoor air is identical to outdoor air.

Outdoor AQI Is Not the Same as Your Indoor PM2.5 Reading

Outdoor air-quality information is valuable.

But it does not directly tell you the exact PM2.5 concentration in your bedroom, office or classroom.

Indoor conditions depend on many factors, including:

Building design.

Windows.

Doors.

Air leakage.

Filtration.

Air purifiers.

Ventilation.

Indoor particle sources.

Therefore, if you want to know what is happening inside a specific room, indoor measurement provides additional information.

Why Closing Windows Can Help with Particles

When outdoor particulate pollution is elevated, reducing uncontrolled outdoor particle entry can influence indoor PM2.5.

This is why many households close windows during haze.

Air purifiers may then be used to reduce particles already inside the room.

But this creates another question:

What happens to CO2 when the room remains closed and occupied?

CO2 During Haze

Imagine four family members inside an air-conditioned living room.

The windows are closed because outdoor air quality is poor.

The doors remain mostly closed.

An air purifier is operating.

PM2.5 gradually decreases.

But everyone remains inside for several hours.

People continue exhaling CO2.

If fresh-air exchange is limited, CO2 may increase.

You can therefore observe:

PM2.5 ↓

while:

CO2 ↑

This is not contradictory.

The two measurements describe different indoor air-quality processes.

Why an Air Purifier Doesn't Tell the Whole Story

An air purifier may be very useful for controlling particulate pollution.

But a typical particulate purifier should not automatically be expected to remove CO2.

The purifier may successfully reduce:

PM2.5.

Dust.

Smoke particles.

Other filterable particles.

Meanwhile, CO2 can still increase because of occupancy.

This is why looking only at the purifier's PM2.5 indicator may not provide a complete picture of the occupied room.

Air Conditioner + Air Purifier + Closed Windows

This is a common Malaysian haze setup.

Air conditioner: keeps the room cool.

Air purifier: helps manage particles.

Closed windows: may reduce outdoor particle entry.

But where is the fresh-air exchange coming from?

The answer depends on the building and ventilation system.

Do not automatically assume the air conditioner is supplying sufficient fresh outdoor air.

Measure the room if CO2 is part of your concern.

Why Temtop M10+ Is Useful During Haze

The Temtop M10+ combines several measurements in one indoor monitor, including:

CO2

PM2.5

TVOC

AQI

Temperature

Humidity

This makes it useful when users want to understand both:

Particulate conditions

and:

Occupied-room conditions

during haze.

Instead of watching only PM2.5, users can see how multiple parameters change together.

Step 1: Establish Your Normal Indoor Condition

Before changing everything, understand the normal room pattern if possible.

Record:

PM2.5.

CO2.

Temperature.

Humidity.

Number of occupants.

Window condition.

Door condition.

Air purifier status.

This provides a useful baseline for comparison.

Step 2: Compare Outdoor and Indoor Conditions Carefully

Outdoor haze information can help provide context.

Indoor monitoring tells you what is happening inside your actual room.

Do not expect the numbers to be identical.

A building may reduce outdoor particle penetration.

Or indoor sources may cause indoor PM2.5 to behave differently.

The useful question is:

How does my indoor environment respond when outdoor conditions change?

Step 3: Monitor PM2.5 Before Switching On the Air Purifier

If practical, observe the room's PM2.5 condition before purifier operation.

Then switch on the purifier.

Continue monitoring.

Observe:

15 minutes later.

30 minutes later.

One hour later.

Longer if required.

This gives you a trend rather than one before-and-after snapshot.

Step 4: Continue Watching CO2

Do not stop at PM2.5.

If people remain inside the closed room, continue watching CO2.

Ask:

Does CO2 remain relatively stable?

Does it gradually increase?

Does occupancy affect the trend?

What happens when someone opens the door?

What happens after people leave?

This gives you a broader understanding of the room during haze conditions.

Step 5: Record Occupancy

Occupancy is important.

A living room with one person can behave differently from the same room with:

Four people.

Six people.

A family gathering.

Likewise, an office meeting room containing ten employees can behave differently from an empty room.

Record the number of people when interpreting CO2 trends.

Haze Monitoring in a Bedroom

Bedrooms deserve special attention because they can remain occupied continuously for many hours.

A typical situation:

Two occupants.

Air conditioner running.

Windows closed.

Door closed.

Air purifier running.

Eight hours of sleep.

During this period, PM2.5 and CO2 can follow very different trends.

A multi-parameter monitor helps you observe both.

Haze Monitoring in an Office

Offices may have central ventilation or different HVAC arrangements, so each building should be evaluated according to its actual system.

Useful areas to monitor can include:

Open offices.

Meeting rooms.

Reception areas.

Training rooms.

Private offices.

Rooms with different ventilation characteristics.

Instead of assuming the whole building behaves identically, compare representative locations.

Meeting Rooms During Haze

Meeting rooms are particularly interesting.

During haze, building operators may want to limit outdoor particle entry.

At the same time, a meeting room may suddenly contain ten or fifteen people.

The facility team therefore has two different concerns:

Particulate pollution

and:

Occupancy-related CO2

Monitoring both parameters helps distinguish the two.

Classroom Monitoring During Haze

Schools can face a similar challenge.

Outdoor particulate pollution may be elevated.

Windows may be kept closed.

Air purifiers may be used.

But classrooms also contain many occupants.

This creates a need to understand:

Indoor PM2.5.

CO2 trend.

Temperature.

Humidity.

Ventilation conditions.

A PM2.5 reading alone cannot answer every classroom air-quality question.

How to Check Whether Your Air Purifier Is Helping

A simple observation can be performed.

Record PM2.5 before purifier operation.

Switch on the purifier.

Keep the monitor in a consistent location.

Observe the trend.

If PM2.5 decreases over time under comparable conditions, this provides useful information about how the room is responding.

However, remember that results depend on factors such as:

Room size.

Purifier capacity.

Filter condition.

Airflow.

Outdoor particle entry.

Indoor particle sources.

Monitor location.

Do not judge the purifier based on one uncontrolled measurement.

Don't Put the Monitor Directly Beside the Purifier Outlet

If you want to understand general room conditions, placing the monitor immediately beside the clean-air outlet may give a local measurement that does not represent the occupied area.

For room monitoring, choose a representative location.

If you specifically want to test the purifier outlet, that is a different measurement objective.

Don't Put the Monitor Beside an Open Window

The same principle applies to windows.

A monitor directly beside an open window may be strongly influenced by outdoor air entering at that location.

That may be useful if you are specifically investigating particle entry.

But it may not represent the average occupied area.

Define the measurement objective before choosing the location.

Kitchen Activities Can Affect PM2.5

Not every high indoor PM2.5 reading during haze comes from outside.

Indoor activities can also generate particles.

Cooking is one example.

If PM2.5 suddenly increases while cooking is taking place, do not automatically attribute the entire increase to haze.

This is why context matters.

Record what is happening inside the home when interpreting the data.

TVOC During Closed-Room Conditions

The M10+ also provides TVOC monitoring.

TVOC trends may be influenced by various indoor materials and activities.

Examples can include:

Cleaning products.

New furniture.

Renovation materials.

Household chemicals.

Other VOC sources.

However, TVOC is not the same as dedicated formaldehyde measurement.

If HCHO is specifically required, choose an appropriate HCHO-capable instrument.

Humidity During Haze

Humidity can also be useful context in Malaysian indoor environments.

Air-conditioning operation, occupancy and outdoor conditions can influence indoor humidity.

Although humidity does not replace PM2.5 or CO2 measurement, it helps provide a broader picture of the indoor environment.

A Simple Haze Monitoring Checklist

During a haze period, record:

Outdoor air-quality context

Indoor PM2.5

Indoor CO2

Temperature

Humidity

Number of occupants

Window condition

Door condition

Air purifier operation

Air-conditioning operation

Then observe how these variables change throughout the day.

Morning vs Evening

Indoor conditions may not remain constant.

Compare:

Morning.

Afternoon.

Evening.

Overnight.

Outdoor haze levels may change.

Occupancy may change.

Doors may open more frequently.

Cooking may occur.

Air purifiers may operate at different speeds.

A full-day trend is therefore more informative than one random measurement.

Should You Use Temtop M10+, S1+ or P600?

The answer depends on what you need to measure.

Temtop M10+

Consider M10+ when you want broader monitoring involving:

CO2 + PM2.5 + TVOC + temperature + humidity

This is useful when closed-room occupancy and particulate pollution both matter.

Temtop S1+

Consider a suitable S1+ configuration when your application is more focused on everyday PM2.5 and home air-quality observation.

Temtop P600

Consider the P600 when your application is more strongly focused on particulate measurements such as:

PM2.5

PM10

This can be useful for haze, dust and particle-focused investigations.

Always confirm the current specification of the exact model before purchasing.

Which One Is Better During Haze?

There is no need to choose based only on which instrument has more functions.

Ask what you want to investigate.

If the question is:

“How much PM2.5 is indoors?”

choose an appropriate PM2.5 monitor.

If the question is:

“What are my PM2.5 and PM10 levels?”

a particulate-focused instrument may be appropriate.

If the question is:

“What happens to PM2.5 and CO2 when we close the room during haze?”

a multi-parameter monitor such as the M10+ becomes particularly useful.

Don't Use Indoor Monitors as a Substitute for Official Outdoor Haze Information

An indoor air-quality monitor tells you about the environment being measured by that device.

For official outdoor air-quality information, public health guidance and haze advisories, refer to the relevant Malaysian authorities.

Indoor monitoring is complementary.

It helps you understand your own indoor space.

How to Monitor Indoor Air Quality During Haze Malaysia

A practical approach is:

Check outdoor conditions.

Measure indoor PM2.5.

Observe the effect of filtration.

Monitor CO2 when the room is closed and occupied.

Record temperature and humidity.

Keep monitor placement consistent.

Compare trends rather than one isolated number.

The key is understanding that cleaner particulate air does not automatically mean every indoor air-quality parameter is ideal.

During haze, PM2.5 may be the immediate concern.

But when people respond by spending many hours in closed indoor spaces, CO2 becomes another useful parameter to monitor.

This is where the Temtop M10+ can provide a broader picture of the indoor environment.

Contact MTM Precision

MTM Precision Sdn. Bhd. (744811-A)

Showroom & Service Centre

No. 29-1 & 29-2, Jalan Bandar 18,

Pusat Bandar Puchong,

47160 Puchong, Selangor, Malaysia

Telephone: +603-8080 7172

WhatsApp: +6016-660 7346

Email: mtmpre@yahoo.com / enquiry@mtmpre.com.my

Website: www.mtmpre.com.my

Contact MTM Precision for Indoor Air Quality Monitor Malaysia, Temtop M10+ quotation and assistance selecting Temtop monitors for haze, PM2.5, CO2 and indoor environmental monitoring applications.