How to Improve Indoor Air Quality in Schools During Winter Pollution

How to Improve Indoor Air Quality in Schools During Winter Pollution

Winter air pollution can make it difficult for schools to maintain healthy indoor environments, particularly in cities such as Delhi NCR, where outdoor pollution levels can rise significantly. Classrooms, laboratories, libraries, canteens and other shared spaces may experience poor indoor air quality when ventilation is inadequate or polluted outdoor air enters the building.

Quick Answer:

Schools can improve indoor air quality by monitoring outdoor AQI, controlling pollution sources, using suitable air filtration, installing fresh air systems, maintaining ventilation systems and establishing a regular indoor air quality management plan. The right approach depends on classroom occupancy, building design, outdoor pollution levels and existing ventilation arrangements.

Why Indoor Air Quality Matters in Schools During Winter

Students and teachers spend several hours inside classrooms every day. When indoor air quality is poor, dust, particulate matter, carbon dioxide, moisture and other airborne pollutants can accumulate, especially in crowded or poorly ventilated spaces.

Winter conditions can make the problem more challenging. Schools may keep windows closed to avoid cold air, while outdoor pollution can make uncontrolled ventilation less suitable during certain periods.

Improving indoor air quality can help schools:

• Reduce the entry and accumulation of airborne particles through appropriate filtration and pollution-control measures.
• Manage indoor carbon dioxide levels by providing adequate ventilation.
• Control odours and pollutants from cleaning products, laboratories and other indoor sources.
• Improve ventilation in crowded classrooms and shared spaces.
• Establish a more consistent indoor environmental management routine.

Good indoor air quality requires a combination of source control, appropriate filtration, adequate ventilation and regular maintenance.

Source: Get an indoor air quality monitor for school

Common Causes of Poor Indoor Air Quality in Schools

Several factors can affect indoor air quality during winter:

• Outdoor air pollution: Fine particulate matter, including PM2.5, may enter through open windows, doors and building air intakes.
• Poor ventilation: Closed windows and insufficient outdoor-air supply can allow carbon dioxide and indoor-generated pollutants to accumulate.
• High classroom occupancy: Students and teachers generate carbon dioxide during normal occupancy.
• Dust accumulation: Dust on floors, furniture, curtains and other surfaces can become airborne during classroom activities.
• Indoor chemical emissions: Cleaning products, paints, art materials and laboratory activities may release gases or particles.
• Inadequate exhaust ventilation: Canteens, toilets, laboratories and other pollutant-generating spaces may need dedicated exhaust systems.
• Poor system maintenance: Dirty filters, blocked air intakes and neglected ventilation equipment can reduce system performance.

Identifying the main pollution sources helps schools select practical and effective control measures.

10 Ways to Improve Indoor Air Quality in Schools During Winter Pollution

1. Monitor Outdoor Air Quality Regularly

Check the local Air Quality Index (AQI), particularly before school hours and during periods of severe pollution. Use reliable local monitoring sources to guide decisions about outdoor activities and natural ventilation.

When outdoor pollution is high, schools should follow applicable public-health and education-authority guidance and avoid bringing in unfiltered outdoor air unnecessarily.

2. Reduce the Entry of Polluted Outdoor Air

Inspect doors, windows, wall openings and outdoor-air intakes for gaps or poorly controlled air entry. Keep doors and windows closed when outdoor pollution is severe, where appropriate, while ensuring that the building continues to receive adequate ventilation through a suitable system.

Avoid sealing classrooms in a way that causes carbon dioxide and other indoor-generated pollutants to build up.

3. Balance Ventilation with Outdoor Pollution Conditions

Opening windows can provide fresh air, but it may also introduce polluted outdoor air during winter pollution episodes. Schools should consider outdoor AQI, indoor carbon dioxide, classroom occupancy and the available ventilation system when deciding how to ventilate occupied spaces.

Where natural ventilation is unsuitable, a properly designed mechanical ventilation system with suitable filtration may offer more controlled outdoor-air delivery.

4. Consider a Fresh-Air Ventilation System with Suitable Filtration

A fresh-air ventilation system can supply outdoor air to classrooms and other occupied spaces. When configured with suitable filtration, it can help reduce the amount of airborne particulate matter entering with the incoming air.

When evaluating a system, schools should consider:

• Outdoor-air delivery capacity for the room’s size and occupancy.
• Filter efficiency and suitability for the expected pollutants.
• Air distribution throughout the occupied space.
• Operating noise and energy consumption.
• Filter replacement access and maintenance requirements.

INTELLIFAN Fresh Air Ventilation Systems are worth considering for schools evaluating controlled fresh-air supply. The appropriate configuration should be selected according to the building layout, ventilation requirements and filtration needs.

Explore the INTELLIFAN Fresh Air Ventilation Systems range or contact the technical team to discuss your project requirements.

5. Use Air Purifiers Where Appropriate

Portable air purifiers equipped with appropriately sized, high-efficiency particle filters can help reduce airborne particles in classrooms. Select a unit based on the room’s floor area, ceiling height, occupancy and clean air delivery rate (CADR).

For effective operation:

• Choose a unit with sufficient clean-air delivery for the room.
• Follow the manufacturer’s guidance on filter replacement.
• Place the purifier where airflow will not be obstructed.
• Operate it at a suitable setting during occupied periods.
• Check noise levels to avoid disrupting lessons.

Air purifiers generally recirculate and filter existing indoor air. They do not replace the need for adequate outdoor-air ventilation or carbon dioxide management.

6. Reduce Dust Inside Classrooms

Dust-control measures can reduce the amount of particulate matter that becomes airborne during daily school activities.

Schools should:

• Clean floors and frequently touched surfaces regularly.
• Use damp cleaning methods or suitable vacuum equipment rather than dry sweeping that disperses dust.
• Maintain curtains, carpets and upholstered furniture.
• Keep storage areas organised to minimise dust accumulation.
• Avoid unnecessary clutter around ventilation outlets and air intakes.

Cleaning schedules should minimise classroom disruption and follow appropriate safety guidance.

7. Control Pollution from Laboratories, Art Rooms and Cleaning Products

Some indoor activities can introduce pollutants even when outdoor air quality is acceptable. Laboratories, art rooms, workshops and cleaning operations may release particles, vapours or other contaminants.

Schools should store chemicals correctly, follow product safety instructions, use lower-emission materials where practical and provide suitable local exhaust ventilation for activities that generate pollutants. Laboratory fume cupboards and other specialised extraction equipment should be used where required.

8. Maintain Exhaust Ventilation in Canteens and Toilets

Canteens, kitchens, toilets and selected utility areas can generate odours, moisture, heat and other pollutants. Suitable exhaust ventilation helps remove these contaminants at or near their source.

Schools should inspect exhaust fans, clean accessible grilles and check that discharged air does not re-enter the building through nearby outdoor-air intakes or windows. Exhaust systems must also have an appropriate replacement-air path to work effectively.

9. Control Dampness and Excess Moisture

Leaks, condensation and persistent dampness can contribute to mold growth and other indoor environmental problems.

Schools should repair plumbing and roof leaks promptly, dry wet materials, inspect areas with recurring condensation and maintain suitable indoor humidity. Any visible mould or persistent moisture problem should be addressed at its source rather than simply covered or cleaned superficially.

10. Create a Regular Ventilation and Filter Maintenance Plan

Even a well-selected ventilation or filtration system needs routine maintenance. Poorly maintained equipment may deliver less airflow than intended or fail to provide the expected level of filtration.

A maintenance plan should include:

• Inspecting filters and replacing them according to manufacturer guidance and actual operating conditions.
• Checking outdoor-air intakes and exhaust outlets for obstructions.
• Cleaning accessible grilles and ventilation components.
• Checking fan operation, airflow and unusual noise.
• Reviewing indoor carbon dioxide trends in occupied classrooms.
• Recording inspections, filter changes and repairs.

Schools should arrange professional inspection when ventilation performance is uncertain or when system faults cannot be resolved through routine maintenance.

Is an Air Purifier Enough for a School Classroom?

An air purifier can help reduce airborne particles, but an air purifier alone may not address every indoor air quality problem. Most portable units filter recirculated room air rather than supplying outdoor air.

A complete classroom strategy should consider:

• Particle filtration: Use a purifier or central filtration system sized for the space and its occupancy.
• Fresh-air ventilation: Provide adequate ventilation while managing the risks associated with polluted outdoor air.
• Carbon dioxide: Monitor levels as an indicator that ventilation may need review.
• Pollution source control: Reduce dust, chemical emissions and pollutants generated by school activities.
• Maintenance: Keep filters and ventilation equipment in suitable working condition.

The most appropriate combination depends on the school’s building, pollution conditions and operational requirements.

How to Choose the Right Ventilation Solution for a School

Before selecting a ventilation system, schools should assess the following factors:

• Classroom size and occupancy: Estimate the outdoor-air requirement based on room volume, the number of occupants and applicable ventilation guidance.
• Outdoor pollution levels: Identify the pollutants of concern and select filtration suitable for the application.
• Airflow distribution: Check whether air can reach occupied areas without creating uncomfortable draughts or significant dead zones.
• Noise and energy use: Consider classroom acoustics and the expected operating schedule.
• Maintenance requirements: Confirm that filters, fans and other components can be inspected and serviced.
• Building constraints: Review duct routes, available installation space, existing HVAC equipment and electrical requirements.

For schools considering a fresh-air ventilation upgrade, INTELLIFAN’s Fresh Air Ventilation Systems can be reviewed as one option. System selection should be based on the project’s actual ventilation and filtration requirements rather than product type alone.

Indoor Air Quality Checklist for Schools

Use this checklist as part of a routine facility-management plan.

• Check outdoor AQI and relevant pollution advisories.
• Review indoor air quality concerns in classrooms and shared spaces.
• Monitor carbon dioxide in representative occupied rooms where possible.
• Check air purifiers and ventilation systems for correct operation.
• Inspect filters and replace them when required.
• Clean classrooms using suitable dust-control methods.
• Inspect laboratory, kitchen and toilet exhaust systems.
• Address leaks, dampness and visible mould promptly.
• Keep outdoor-air intakes and exhaust outlets unobstructed.
• Record maintenance activities and arrange professional assessments when necessary.

Conclusion: Improve School Indoor Air Quality with a Planned Ventilation Strategy

Improving indoor air quality during winter pollution requires more than keeping windows closed or installing an air purifier. Schools need a practical strategy that combines outdoor AQI monitoring, source control, suitable filtration, adequate ventilation and regular equipment maintenance.

For schools evaluating controlled outdoor-air supply, INTELLIFAN Fresh Air Ventilation Systems are an option to consider based on the building’s ventilation and filtration requirements.

Planning a ventilation upgrade for your school?

 Explore the INTELLIFAN Fresh Air Ventilation Systems range or contact the INTELLIFAN technical team to discuss your project requirements