Summer in Taiwan is both hot and humid, and the air conditioner is the largest single item in household electricity use. According to Energy Administration, Ministry of Economic Affairs (經濟部能源署) statistics over the years, air conditioning accounts for roughly 40 to 50% of residential electricity use in summer. AC maintenance therefore affects more than how cold the air feels: it also determines your electricity bill and the life of the machine. This article separates what homeowners can do themselves from what must be left to professional technicians, and explains a few of the most common myths.
Filters and housing: what owners can do every 2 to 3 weeks
- Nylon filters: Remove them and rinse with clean water, using a soft brush gently if needed. Dry them in a cool, shaded place. Do not leave them in strong sunlight, because the plastic frame becomes brittle and warps. For heavily used units, homes with pets, or homes facing a main road, cleaning every 2 weeks is recommended.
- Air outlet and louvers: Wipe with a dry or slightly damp cloth. Do not spray water directly into the unit.
- Around the outdoor unit: Keep the area within 50 cm free of clutter, flower pots and drying racks that block heat dissipation. Poor heat dissipation makes the compressor run under high load for long periods.
- Run fan mode before switching off: On older models, switching to fan mode for 10 to 20 minutes before turning off dries the moisture on the evaporator and reduces mold growth. Most newer models have an automatic drying function; just turn it on as the manual describes.
Full-unit cleaning: why homes in Taipei and New Taipei should do it every 1 to 2 years
Filters only catch the larger dust. Fine dust, cooking oil fumes and moisture pass through the filter and build up on the evaporator's aluminum fins, the blower wheel and the drain pan. The Taipei basin is humid in summer, so black mold and jelly-like biofilm grow easily on these parts. Typical signs include:
- A sour or musty smell from the air outlet when the unit starts.
- Noticeably weaker airflow even though the filter is clean.
- Slower dripping from the drain outlet, or even water dripping from the indoor unit. This is usually the drain pan or drain pipe blocked by biofilm.
A full-unit cleaning (commonly called "washing the AC", 洗冷氣) removes the panel and blower wheel, cleans the aluminum fins and blower wheel with a high-pressure water jet and a dedicated cleaning agent, and clears the drain pipe. Because it involves taking the unit apart and keeping water off the circuit board, it is best done by a technician who holds a refrigeration and air-conditioning installation and repair technician certificate (冷凍空調裝修技術士證照). Once every 1 to 2 years is enough for an ordinary home; restaurants and units near kitchens need it more often.
Why "just top up the refrigerant" often treats the symptom, not the cause
Refrigerant circulates in a sealed loop and is not "used up" under normal conditions. If a technician measures low refrigerant pressure, that means there is already a leak somewhere in the copper pipes, joints or valves. Topping up refrigerant without finding the leak means the unit stops cooling again a few months later, and low refrigerant raises the compressor's discharge temperature and shortens its life. The correct approach is to run a pressure-hold test first to find the leak and re-braze it, then recharge to the charge amount marked for that model.
Another common situation is "the AC does not cool but the refrigerant is normal". The cause is then usually a dirty filter and evaporator, poor heat dissipation at the outdoor unit, or a unit whose capacity (tonnage) was never enough for a west-facing or high-ceilinged space. You can first use the AC tonnage calculator to check whether the unit size is reasonable.
Efficiency labels and electricity bills: how to read CSPF
Since 2017, Taiwan has used CSPF (Cooling Seasonal Performance Factor) as the efficiency indicator for split-type air conditioners. A higher number means less electricity for the same cooling effect. The Energy Administration's energy efficiency grade label sorts units into grades 1 to 5. Rules of thumb:
- Replacing an old fixed-speed unit with a Grade 1 inverter unit can cut cooling electricity use by 30% or more.
- Each 1°C increase in the set temperature saves roughly 6% of AC electricity. With a fan moving the cool air around the room, most people still feel comfortable at 26 to 28°C.
- A well-maintained unit keeps efficiency close to what it had when new; dirty aluminum fins can make actual power consumption 10 to 20% higher.
The actual CSPF of each model can be found on the Energy Administration's energy efficiency grade label lookup platform.
Jobs homeowners should not do themselves
| Item | Why it should go to a professional |
|---|
| Refrigerant pressure testing, leak detection and re-brazing | Needs pressure gauges, a vacuum pump and welding equipment; incorrect handling risks frostbite and bursting. |
| High-pressure chemical washing of the blower wheel and aluminum fins | The unit must be taken apart and the circuit board properly protected; improper washing can cause short circuits or bent fins. |
| Re-setting the slope of concealed drain pipes in the ceiling | Insufficient slope causes long-term dripping and mold growth, and the work requires opening the ceiling. |
| Dedicated 220V circuit and earth-leakage circuit breaker (ELCB, 漏電斷路器) | An air conditioner should use a single dedicated circuit, and the wiring and breaker specifications must comply with the Regulations for Installation of Customer Electrical Equipment (用戶用電設備裝置規則). |
For a detailed explanation of electrical circuits, see the old-house electrical safety guide.
Frequently asked questions
The breaker trips as soon as the AC starts. Is the machine broken?
First check whether the AC shares a circuit with other high-power appliances. Older apartments often connect the AC to an ordinary outlet circuit, and the large current when the compressor starts can easily trip the no-fuse breaker (NFB, 無熔絲開關). If it still trips on a separate circuit, the compressor or capacitor may be faulty and a technician needs to measure it.
Is a dripping indoor unit always a blocked drain pipe?
The most common cause is a drain pipe or drain pan blocked by biofilm. Next is a drain pipe with insufficient slope or one that has been flattened. In a few cases it is frost on the evaporator melting and dripping (usually linked to low refrigerant or low airflow).
When should I replace an AC with a new one?
The compressor's design life is generally about 10 to 15 years. If the unit is more than 10 years old, the repair cost exceeds 1/3 of the price of a new unit, or it is still a fixed-speed model, replacing it with a Grade 1 inverter unit can usually pay for itself through the electricity bill difference within 3 to 5 years.
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