Living in Taipei and New Taipei, one of the most troublesome home problems is definitely "mold on the walls". Every year, the continuous drizzle in winter and spring, or the sultry humidity in summer afternoons, always leave patches of black-green mildew spots uninvited on corners, ceilings, and even behind furniture. These molds are not only an eyesore, but also a potential health killer. Today, we’ll take a closer look at this problem and learn how to combat it.
### Why is my home so prone to mold? Understand the three main culprits of mold growth
Mold spores are actually everywhere, but they need the right environment to take root. The average relative humidity in the Taipei Basin is as high as 70%-80% year-round, which provides a perfect breeding ground for mold. But in addition to the general environment, the "micro-environment" in your home is even more critical:
1.
: This is the first condition. Improper drying of the bathroom, moisture from cooking in the kitchen, drying clothes indoors, or leaks in wall pipes can cause local humidity to soar. According to the Taiwan Indoor Environmental Quality Management Association, humidity exceeding 60% for a long time is enough for mold to start growing.
2.
: Mold is most active between 20 degrees Celsius and 35 degrees Celsius, which is exactly the indoor temperature in Taiwan in most seasons.
3.
: This is often overlooked. Mold does not eat cement or paint, but dust, dander, soap residue attached to the wall, or organic components in the wall paint. The unclean the surface, the more food there is for mold.
It is important to note that many mold problems are actually caused by condensation. When warm, moist air comes into contact with a cold wall (such as the inside of an exterior wall or an uninsulated concrete wall), the moisture condenses into small water droplets invisible to the naked eye and infiltrates the wall. This is very common when heating is used in autumn and winter, or in the corners of the exterior walls of air-conditioned rooms in summer.
### Health should not be ignored: don’t treat mold as a simple stain
Many people think mold is unsightly but underestimate its health effects. Mold hyphae release tiny spores and volatile organic compounds (MVOCs), which can cause or exacerbate a variety of health problems:
-
: This is a common reaction that can cause sneezing, runny nose, itchy eyes, and even trigger an asthma attack.
-
: For the elderly and children with weak immunity, it may cause respiratory infections or fungal sinusitis.
-
: A few molds (such as the famous "black mold" Stachybotrys chartarum) produce mycotoxins, and long-term exposure may cause more serious neurological or immune system problems.
Therefore, dealing with mold is not only for the aesthetics of your home, but also for the health of your family.
### Four steps of DIY mold removal and repair (safety first!)
When faced with mold in a small area (an area less than 1 square meter), you can try to deal with it yourself. Please be sure to take precautions: wear an N95 mask, rubber gloves and goggles.
1. Use plastic sheeting to isolate the work area to prevent the spread of spores.
2. Never dry brush directly, as this will cause spores to fly everywhere. The wall should be lightly sprayed with diluted soapy water or commercial mildew removal spray to prevent the spores from spreading easily.
3. For non-porous surfaces (such as ceramic tiles, glass, and painted surfaces), use a hard-bristled brush with detergent to remove them. For porous surfaces (such as cement walls, calcium silicate boards, wallpaper), the cleaner may only treat the surface and the mold roots have penetrated deeply.
After cleaning, sterilization must be carried out to prevent recurrence. Common and relatively safe DIY fungicides include:
-
: Effective on non-porous surfaces, but highly irritating, requires ventilation and may discolor some materials. Note: Never mix it with ammonia or other cleaning agents, as it will produce deadly poisonous gas!
-
: It is milder than bleach and has good sterilization and color removal effect.
-
: A natural choice, but its bactericidal power is weaker than the previous two, suitable for minor cases.
Spray the fungicide on the wall, let it sit for 15-20 minutes, and then wipe it with a clean damp cloth.
This is the key of keys! The treated area must be allowed
to. You can use a dehumidifier or electric fan to blow against the corner of the wall, and open windows to promote ventilation (if the outdoor humidity is lower than indoors). Check whether there are any sources of water seepage, such as leaking window frames, leaking water pipes, etc., which must be resolved together.
For damaged calcium silicate boards or paint layers, it may be necessary to scrape off the loose parts, fill them up with anti-mildew soil, and finally apply
and
. There are many paints on the market that claim to be anti-mildew. It is recommended to choose a reputable brand and make sure the bottom surface is completely dry and clean before painting.
### When should you call a professional team?
If the following situations occur, it is strongly recommended to seek the assistance of a professional waterproofing and mildew-proof engineering company:
- The moldy area exceeds 1 square meter (approximately 3.3 square meters).
- If mold reappears after cleaning, it means there may be a persistent moisture problem inside the wall.
- The walls show signs of structural damage such as peeling paint, bulging wallpaper, softening of drywall.
- Suspected water seepage and mold caused by cracks in building exterior walls, leaking roofs or broken pipes.
The professional team will use thermal imaging cameras, hygrometers and other tools to detect leakage points, and carry out waterproofing projects and repair structures from the root cause. This is a long-term solution. In Taipei and New Taipei, this type of service is very common.
### Long-term prevention: Create an environment where mold can’t survive
To eradicate mold, prevention is better than cure. You can start with the following points:
1.
: Purchase a reliable dehumidifier to control indoor humidity between 50% and 60% during the humid season. This is the most cost-effective investment.
2.
: Make it a habit to open windows every day to allow for convection (avoiding rainy or hazy days). Ventilation fans must be installed in bathrooms and kitchens and run continuously for at least 20 minutes after bathing or cooking.
3.
: The dehumidification mode of the air conditioner is very useful in summer. Be careful not to set the air conditioner temperature too low, which may cause a large temperature difference with the outdoor temperature and aggravate condensation.
4.
: Do not place large furniture (such as wardrobes and bookcases) close to the exterior wall. Leave a gap of at least 5 centimeters to allow air to circulate and prevent the back from becoming a breeding ground for mold.
5.
: Always pay attention to corners that are prone to moisture such as window frames, air-conditioning drain pipes, under kitchen sinks, and bathroom baseboards to detect and deal with them early.
When faced with humid climates, instead of complaining, take the initiative to manage your indoor environment. From today on, through correct knowledge and habits, you can say goodbye to annoying wall mold spots and protect a dry, comfortable and healthy home for your family.
New knowledge on air conditioning power consumption and Taiwan climate maintenance regulations in recent years (2025-2026 current situation)
With the high temperatures in summer breaking historical records and the adjustment of electricity price structure in recent years, the latest statistics from the Energy Administration of the Ministry of Economic Affairs show that air-conditioning equipment accounts for more than 47% of residential electricity consumption in summer. Many people mistakenly believe that if the air conditioner is not cold, they only need to "replenish the refrigerant." However, in fact, refrigerant is not naturally consumed during normal operation in a closed circuit. If the refrigerant is insufficient, it means that there are micro leaks in the copper pipes or joints. Simply replenishing the air conditioner will only treat the symptoms but not the root cause. Refrigerant leakage will aggravate the high temperature overload of the compressor and shorten its service life.
According to Taiwan's standard operating specifications for air-conditioning projects, it is recommended that professional technicians with a refrigeration and air-conditioning decoration technician license perform "full machine high-pressure water washing and evaporator deep sterilization" every 1 to 2 years for detached air-conditioning indoor units. Especially in the humid summer in the Shuangbei Basin, the air drum and water collection tray are easy to breed black mold and jelly-like biofilm. This is also the main reason for the sour smell in the air-conditioning outlet and the backflow of the drainage pipe. Regular maintenance can maintain CSPF (Air Conditioning Seasonal Performance Factor) level one energy efficiency level, which can save an average household 15% to 20% of air conditioning electricity bills every year.
Autonomous simple maintenance vs professional maintenance safety red line
- Homeowners can do by themselves: Remove and clean the nylon filter regularly every 2 to 3 weeks (rinse with clean water and dry in a cool place, do not expose it to the sun to avoid deformation and embrittlement); clean the air outlet blades of the indoor unit with a dry cloth; check whether there is any accumulation of debris within 50 cm around the outdoor unit that hinders heat dissipation.
- Professional technicians must be entrusted according to regulations: Refrigerant pressure testing and leakage repair welding, high-pressure cleaning of indoor unit air drums and aluminum fins with liquid chemicals, reset of the drainage slope of hidden cold water pipes in the ceiling, and 220V dedicated power circuit configuration and leakage circuit breaker replacement.
