How to Improve Indoor Air Quality Without an Expensive Purifier

Major indoor pollution sources in Nepal

Indoor air contains pollution generated inside plus outdoor pollution that enters through windows, doors, vents, and leaks. Important sources can include solid-fuel cooking and heating, tobacco smoke, incense, mosquito coils, candles, frying, poorly vented gas appliances, dust, solvents, cleaning sprays, dampness, and mold.

The strongest intervention is often to remove or reduce the source. Filtering a room while smoke continues inside is less effective than stopping the smoke and then cleaning the remaining air.

Cooking and household combustion

Open fires and inefficient stoves using wood, dung, crop waste, coal, or kerosene can produce harmful particles and gases. Cleaner fuels and technologies, safe installation, a separate kitchen where practical, and effective exhaust reduce exposure. A hood should vent outdoors rather than simply recirculate through a weak grease filter.

Never use charcoal or unvented combustion in an enclosed room. Carbon monoxide can be deadly and cannot be detected by smell. Install an appropriate alarm where available and follow appliance safety instructions.

When opening windows helps

Ventilation can dilute pollutants from cooking, cleaning, moisture, and occupants when outdoor air is cleaner. Cross-ventilation can move more air by using openings on different sides, while an exhaust fan removes pollution near its source.

When outdoor PM2.5 or smoke is high, wide-open windows can make indoor particle levels approach outdoor levels. Use the live outdoor trend, indoor conditions, heat safety, and moisture needs to choose a better ventilation window.

Dust, fabrics and cleaning

Cleaning products can also emit irritants. Follow labels, never mix chemical cleaners, use the least polluting product that works, and ventilate safely during and after use.

• Use damp cloths or wet methods instead of dry sweeping when practical
• Wash bedding and curtains regularly
• Clean under furniture and other dust reservoirs
• Use a vacuum with effective particle filtration if available
• Control moisture and repair leaks that support mold

Portable and DIY particle filtration

A portable air cleaner should be sized for the room. Smoke clean-air delivery rate, or CADR, is more useful than a marketing claim alone. Place the device where air can circulate, run it long enough to matter, and replace filters when dirty or according to instructions.

A carefully constructed box-fan filter can be a temporary lower-cost option when proven commercial products are unavailable. Use a modern safety-certified fan, a high-efficiency filter, a stable design, and adult supervision. Do not block exits or use damaged electrical equipment.

What indoor plants can and cannot do

Plants can improve comfort and wellbeing, but a few household plants do not provide enough air cleaning to replace source control, ventilation, or mechanical particle filtration. Wet soil can also support mold or allergens when overwatered.

Using an indoor air monitor

An indoor PM monitor can reveal peaks from cooking, incense, cleaning, or outdoor infiltration and show whether an intervention lowered them. Place it away from a stove, direct purifier outlet, open window, or humidifier unless testing that exact source. Focus on repeated patterns and clearly label sensor uncertainty.

Now act

Practical recommendations

• Do not smoke or burn waste indoors or near doors and windows.
• Use the cleanest practical cooking and heating technology available and vent combustion safely outdoors.
• Operate a kitchen exhaust hood during cooking when it vents outdoors and is maintained correctly.
• Ventilate when outdoor AQI is lower and indoor heat, moisture, and infection risks are considered.
• Damp-dust and clean bedding, curtains, and high-dust areas without aggressively resuspending particles.
• Choose a portable particle cleaner by room size and smoke CADR, and avoid devices that intentionally generate ozone.
• Use an indoor monitor to compare trends before and after interventions, not as a medical instrument.