Try this simple test to see if your air conditioner is harboring an asthma trigger like mould:

- Switch off your air conditioner for half a day.

- After, that switch it on again and smell the air blown from it.

- If you detect a distinct musty or stale smell in the blow air, there could be mould inside the appliance.

Reducing Asthma triggers in your home:

Dust, dirt and moisture encourage the growth or accumulation of asthma triggers like mould, mildew, dust mites and insects parts. Some steps to reduce them are:

- Clean and dry all surfaces in your home regularly.

- Do not allow water to stagnate in any area.

- Dry your laundry in a well ventilated area.

- Clean your air conditioner filter and cooling coil regularly.

- Spray your air conditioner coil and fan blades with a mould inhibitor.

- Wash mattresses, pillows and other beddings regularly.

- Avoid keeping stuffed animals in beds.

- Clean carpets and furnishings regularly.

- Use an air purifier to remove airborne mould spores.

- Use a dehumidifier in damp places.

Creating an 'Allergy Asthma - Friendly Home'

1. Encase all bedding with allergen-proof encasings. Wash these encasings every 2-3 months in 60C hot water to remove dust mites which accumulate on the outer surface. Otherwise, treat them with an anti-mite solution to provide a protective coating lasting up to 3 months, and only wash the encasings in 4-6 months.

2. Most anti-mite mattresses use a chemical coating to reduce mite growth. This coating wears out ni approximately 6 months. Then, these anti-mite mattresses need to be encased with allergen-proof covers to keep them mite-proof in the long run.

3. Wash normal mattress covers, pillow cases and blankets in hot water 60C every two weeks. If no hot-water washing machine is available, use anti-dust mite laundry solutions for normal cold wash.

4. Remove carpeting and fabric rugs. Alternatively, wash carpets and rugs at every 2 weeks or treat with anti-mite solutions to prevent mite growth for up to 3 months.

5. Use a powerful HEPA air purifier to remove airborne allergens including bacteria, dust mites, mould from air conditioner systems, cockroach droppings, grass pollen etc.

6. Use Venetian blinds or window shades. Otherwise, machine-wash them at 60C. Wash every 2 weeks or treat with an anti-mite solution to prevent mites for up to 3 months.

7. Air-condition or dehumidify the room to 50% humidity or less, to discourage mite and mould growth. Fit special filters to air conditioners, to capture the micro particles (mould and bacteria). Wash regular aircon filters weekly. Apply anti-mould treatments to the blower and coolant coil of the aircon to reduce mould and bacteria build-up.

8. Wet mopping minimizes dust uplift when cleaning, and should be done every 2-3 days. Do not sweep as it stirs up a lot of dust particles. Instead, use a HEPA allergy-friendly vacuum cleaner for capturing the dust between wet mopping cycles.

9. Keep books and decorative items in closed cupboards to reduce 'pockets of dust'.

10. Minimize soft furnishings. Wood, leather, plastic or vinyl furniture is best to reduce mite growth.

11. Wipe open surfaces every other day with special dust grabber cloth or a wet cloth, to minimize dust uplift.

12. Wash soft toys every 2 weeks at 60C. Otherwise, put them in plastic bags and place in freezer overnight to kill the dust mite. Then vacuum them out the following day.

13. Ideally keep your pet out of the house, but definitely out of the bedroom.

14. Limit household plants to reduce mould build-up, avoid plants in bedrooms.