Is a 5-tick aircon worth the higher price?

Side-by-side comparison

The National Environment Agency (NEA) rates efficiency on its Energy Label in ticks: 1 Low, 2 Fair, 3 Good, 4 Very Good and 5 Excellent. For aircons, the label covers casement, window, split type (non-inverter), split type (inverter) and portable models. Portable aircons are rated only from 1 to 2 ticks.

Household aircons are also regulated goods under NEA's Minimum Energy Performance Standards (MEPS), which require them to meet a minimum Coefficient of Performance (COP).

How much does a 5-tick aircon save?

NEA does not give a fixed saving for a 5-tick aircon over a 3-tick one. The annual energy cost on each label is worked out under fixed assumptions about electricity price and hours of use, which NEA sets out on its Energy Label page. Your own tariff and hours may differ, so use the label cost to compare models, not to forecast your bill.

To estimate your own saving, first read the annual energy consumption in kWh on each label and find the difference between the two models. Next, multiply that difference by your current tariff, which you can check on the SP Group tariff information page; SP Group says tariffs are revised quarterly to reflect the actual cost of electricity. Finally, scale the result to your own use: if you run the aircon for more hours than the label assumes, the saving grows, and if you run it for fewer, it shrinks.

The aircon running cost calculator can do this sum for each model. Then set the yearly difference against the price gap.

Life cycle cost

NEA's tips on buying energy-efficient appliances suggest looking at life cycle cost, not just purchase price. In words: life cycle cost equals the purchase price plus the annual energy cost multiplied by the lifespan in years. Work it out for each model and compare the totals.

The Energy Label ticks on an aircon tell you about efficiency; life cycle cost turns that into money. A higher purchase price can be offset by lower energy costs over years of use, or it may not be, depending on how many hours you run the unit. No source gives a payback period, so work it out from your own figures.

For the annual energy cost, use your own tariff and hours rather than the label's assumptions. The electricity cost calculator can help you turn kWh into a yearly cost. For lifespan, use the years you expect to keep the unit.

Size and type matter too

NEA's buying tips advise choosing the right cooling capacity. Oversized units cost more to run and may not dehumidify well because they cool too quickly. Undersized units do not cool or dehumidify adequately. A larger aircon may be needed for rooms with double ceiling height, a large window area such as full-height glass, windows facing the sun (east-west) or extra heat sources such as bar fridges.

Each label shows the full load cooling capacity in kW, so check that both models you compare are sized for the room. For a figure in British thermal units (BTU), try the aircon BTU calculator. The label also treats split type (inverter) and split type (non-inverter) as separate types; if you are weighing those too, see inverter vs non-inverter aircon.

Running it efficiently

NEA's energy saving tips for aircon use include these habits:

• Use a fan instead, or run the aircon for a short while and then switch to a fan.
• Set a suitable temperature: the lower the setting, the more energy the aircon uses.
• Close curtains or blinds during the hottest part of the day, or use solar window film.
• Check the filter monthly and clean or replace it when necessary, service the unit regularly and have it inspected annually.

If you are looking for the most energy efficient aircon, NEA does not name one model on its Energy Label page. Look for the highest tick rating among units of the right size for your room. For more on settings that cut energy use, see aircon settings to save electricity.

Which one should you choose?

There is no single winner. If you run the aircon for many hours a day, a higher-tick model is more likely to pay back the price gap through lower energy use. For light use, it may not. Either way, size the unit first, then compare ticks, annual kWh and prices among models of the right capacity. To plan the job, browse aircon companies and read about aircon installation.

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