How much cheaper is a fan than an aircon?

Side-by-side comparison

The Energy Label from the National Environment Agency (NEA) rates efficiency in ticks, from 1 (Low) to 5 (Excellent). It covers air-conditioners, refrigerators, clothes dryers, televisions, water heaters and lamps, but not fans (NEA: The Energy Label). Portable aircons are rated only from 1 to 2 ticks. For split and multi-split aircons, the label is affixed to the outdoor unit. It shows the aircon's annual energy consumption in kWh and its size as full load cooling capacity in kW.

NEA says appliances with more ticks on the Energy Label are generally more energy efficient (NEA: Tips on buying energy-efficient appliances). To turn an aircon's label kWh into your own estimate, use the aircon running cost calculator. For a fan, start from the wattage on its label instead.

Aircon vs fan electricity: what NEA estimates

NEA's energy saving tips give two estimates that answer the question directly. Using a fan instead of an aircon saves about 26% of utility costs. Running the aircon for a short while (1 hour) and then switching to a fan saves about 23%. Both estimates assume a 4-tick single-split aircon of 2.6kW cooling capacity and/or a 50W fan.

Treat these as NEA's estimates under its assumptions, not your bill (NEA: Energy saving tips). Your aircon may have a different cooling capacity or tick rating, your fan a different wattage, and your hours will be your own. So your own fan vs aircon cost gap may differ from NEA's figures.

The difference comes from what each machine does: an aircon cools and dehumidifies the room, while a fan only moves air.

Working out your own running cost

Your bill also depends on the tariff, which changes. SP Group's tariff page says the regulated electricity tariff is revised every quarter to reflect the actual cost of electricity. It has four components: energy costs, network costs, the market support services fee and the market administration and power system operation fee. Check the current tariff there.

Next, find each appliance's consumption. For a fan, use the wattage printed on its label. The same applies to ceiling fan electricity: a ceiling fan's wattage is on its label, so compare models by that figure. For an aircon, use the annual kWh on its Energy Label. Put the wattage or kWh and your usual hours into the electricity cost calculator to see your own estimate.

Using both together

Cooling a room does not have to be aircon or fan. NEA's tips combine them: run the aircon for a short while (1 hour), then switch to a fan, which NEA estimates saves about 23%. While the aircon is on, NEA suggests setting it at 25 degrees C, noting that each degree raised saves about 3%, and setting the timer to switch it off half an hour earlier, which saves about 2% (NEA: Energy saving tips). These are NEA's estimates under its assumptions of a 4-tick single-split aircon of 2.6kW cooling capacity and/or a 50W fan. NEA does not give a figure for running the aircon and a fan at the same time. For the settings in detail, see aircon settings that save electricity.

Which one should you choose?

Use these as a quick guide by situation:

• Mild day or evening: use a fan alone when it keeps you comfortable. It only moves air, so it is the lower-cost way to stay cool.
• Hot night: run the aircon for a short while, then switch to a fan, as NEA suggests.
• Hot or humid room: use the aircon, and check its filter once a month, cleaning or replacing it when necessary, so it runs efficiently (NEA: Energy saving tips).
• Buying a fan: the Climate Friendly Households Programme lists direct current (DC) fans, with a DC motor and excluding those with non-LED lights, among its eligible products.
• Buying an aircon: choose the right cooling capacity. NEA says oversized units cost more to run and may not dehumidify well, while undersized units do not cool or dehumidify adequately (NEA: Tips on buying energy-efficient appliances). Compare aircon types before you decide.

If you want a fan on the ceiling, see ceiling fan installation. If you keep the aircon, servicing costs depend on the job, so compare the published rates on the aircon servicing prices page.

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