Inverter or non-inverter aircon: which suits your home?

How each type works

Both types cool your room with a compressor in the outdoor unit. The difference is how that compressor behaves once the room reaches the temperature you set.

Non-inverter

A non-inverter compressor runs at a single speed. It switches fully on until the room is cool enough, then switches off. When the room warms up again, it restarts at full power. Over a long evening, this cycle repeats many times.

Inverter

An inverter compressor speeds up and slows down instead of stopping and starting. It works harder at first to cool the room, then slows down to hold the temperature. Because it keeps running at a lower speed, the room tends to stay steadier.

Compressor type is a separate choice from system layout. For single split, multi-split and other set-ups, see which type of aircon suits your home.

Inverter and non-inverter aircons side by side

The table covers how each type behaves, not what any model costs, since price depends on the brand, capacity and job.

Running costs and the energy label

Every household aircon sold in Singapore must carry NEA's Energy Label, and you should only buy NEA-registered models. The label rates efficiency in ticks: 1 tick is Low, 2 Fair, 3 Good, 4 Very Good and 5 Excellent. It also shows an estimated annual energy cost and consumption, based on stated usage assumptions. For aircons, that means 8 hours of use a day, and NEA notes that actual consumption and cost may vary. See NEA's page on the Energy Label.

The label's type field also separates split type (non-inverter) from split type (inverter). When you shop for an inverter aircon, Singapore's energy label makes the comparison simple: put the labels of the models you are considering side by side, then compare the ticks and the estimated annual cost.

NEA also sets Minimum Energy Performance Standards for regulated household appliances, including air-conditioners. Models below the standard cannot be sold in Singapore.

Running cost also depends on the electricity tariff. SP Group publishes the household tariff and revises it every quarter, so check the current figure on SP Group's tariff page rather than an older number.

Which suits your home

Start with how many hours a day each room is cooled. If you are asking "is inverter aircon worth it?", usage is usually the deciding factor.

Bedrooms and living rooms used for long hours

A bedroom aircon running through the night is a long, steady job. So is a living room aircon in a home where someone is in most of the day or works from home. This is where an inverter tends to make the most sense: once the room is cool, the compressor slows down instead of cycling, with fewer noticeable restarts while you sleep.

Rooms used in short bursts

A study used for an hour or a guest room cooled now and then may not run long enough for an inverter's strengths to matter much. Here a non-inverter aircon with a good tick rating can be a reasonable choice, especially if upfront cost matters to you.

Several rooms on one system

If your home uses a multi-split system, where one outdoor unit serves several indoor units, the number of rooms you connect matters too.

Repairs and lifespan

Inverter aircons rely on more electronics, including the inverter board that controls compressor speed. If that board fails, the repair can cost more than fixing the simpler controls in a non-inverter unit. What you pay depends on the job and the parts needed, so compare aircon companies and their published prices.

Both types need regular servicing. Clean filters help either kind run as it should, and a technician can spot small problems early. How long a unit lasts depends on how often it runs and how well it is looked after.

If an older unit keeps breaking down, see whether to repair or replace an old aircon.

Questions to ask before you buy

• How many ticks does it have? Compare the tick rating of each model you shortlist.
• What is the model number on the label? For split and multi-split aircons, the NEA energy label is fixed to the outdoor unit and shows its model number. Check it matches your quote.
• Is the BTU rating right for the room? Ask the seller to confirm the cooling capacity suits each room.
• What do the warranty terms say? Read the warranty as stated in writing: what it covers and for how long.
• What does the installation include? Ask about piping, trunking, brackets and removal of the old unit. See aircon installation for what the job involves.

Questions