AC Guide · Buying

Inverter vs non-inverter AC: which one should you buy?

By the Citi Cool engineering team. Updated 2026-10-17. Sources: Daikin India, the Bureau of Energy Efficiency, the Ministry of Power and our own service team.

The short answer

• Your AC has power to spare: An inverter saves. It turns down instead of switching on and off. On their BEE labels the FTKU50 5 Star uses 32% fewer units than the GTQ50 non-inverter.¹⁴
• Your AC can't keep up: Neither saves. Top floor, a big room or a 45°C afternoon: both run flat out. At full power the GTKL50 3 Star even draws more, 7.17 A against the GTQ50's 5.8 A.¹¹⁵
• About 4 hours a day: A non-inverter. It rarely breaks down, and a capacitor costs about ₹1,500. An inverter's PCB repair costs about ₹3,500 after the warranty.¹²
• In Delhi heat: Check the series. The GTKL50 inverter loses cooling above 43°C, the same as the GTQ50 non-inverter. The FTKU50 holds full cooling to 46°C.¹⁰

Will an inverter save anything in your room?

A non-inverter has one speed: it runs at full power and switches off when the room is cool. An inverter turns its compressor down to what the room needs. That saves units only in hours when the AC has power to spare. In a hot top-floor room, or on a 45°C afternoon, a 1.5 ton may not reach the setting at all; then both run flat out and the inverter has nothing to turn down.¹¹¹

The room check on this page takes your city, room, floor, window, setting, day and hours, and plays the day hour by hour: what the room needs, what each 1.5 ton AC gives at that hour's heat, and whether it turns down, switches on and off, or runs flat out. Two rooms, worked out:

Middle-floor bedroom, at night: 12 × 12 ft, Delhi, set to 24°C, 10 pm–6 am

The AC keeps up in all 8 of your hours, so an inverter turns down instead of switching on and off. Against the GTQ50's 2.8 units, the GTKL50 uses 2.4 units (14% less) and the FTKU50 1.8 (34% less).¹¹

Top-floor room, afternoons, hottest day: 12 × 12 ft, Delhi, set to 24°C, 12–6 pm

Flat out for part of your day: the GTQ50 is flat out for 2 of your 6 hours, the GTKL50 for 3 and the FTKU50 for none. Flat out, an inverter has nothing to turn down. At full power the GTKL50 draws more than the GTQ50 (7.17 A against 5.8 A), so it ends up using 8.4 units to the GTQ50's 7.4. The FTKU50, rated to give full cooling up to 46°C, saves 1.5 units (20%). A 1.8 ton AC would hold 24°C through all of them.¹¹

The room's heat each hour comes from Daikin's heat-load method, the one our AC calculator uses, with the sun and the heat stored in walls and roof following the day.¹¹ Outside temperatures run between the city's IMD figures for its hottest month.⁹ What each AC can give: rated cooling up to its series' full-capacity temperature, then 5% less per °C.¹⁰ Full power is 230 V × Daikin's rated operating current: GTQ50 5.8 A, GTKL50 7.17 A, FTKU50 5.51 A.⁵ Turned well down, an inverter's efficiency is taken as its ISEER.²

Most AC hours are milder than you think

The Bureau of Energy Efficiency rates every AC sold in India over a 1,600-hour cooling year, spread across outside temperatures from 24°C to 43°C, using weather data from 54 Indian cities.²³

69% of BEE's 1,600 hours (1,111 hours) are at 30°C or cooler outside. 2% (30 hours) are at 40°C or hotter.³

On those mild hours the room needs only part of the AC's power. An inverter turns itself down to match. A non-inverter can only run at full power and switch off, over and over. That is why BEE tests inverter ACs at both full and half capacity before it gives them a star rating.¹³

Your room is not BEE's average room. A top-floor room, a big room or a Delhi afternoon at 45°C can need more than a 1.5 ton gives. In those hours the AC runs flat out, inverter or not, and there is nothing to turn down. The room check above shows when that happens.¹¹

What each one costs you over 5 years

Worked from BEE label averages, which suit a room the AC keeps up with; a room that runs it flat out narrows the inverter's lead. Three 1.5 ton Daikin ACs we sell: today's price plus 5 years of electricity from each AC's own BEE star label, at ₹8 a unit for 8 months a year. The tool on this page lets you change the hours, your electricity rate and the months.

At 4 hours a day, the GTKL50 is ₹1,037 cheaper over 5 years on price and power, but it saves only ₹587 a year in electricity. One PCB repair after the warranty (₹3,500) takes about 6 years of that saving. That is why we suggest the GTQ50 non-inverter for light use.⁴¹²

At 8 hours a day, the FTKU50 (5 Star inverter) costs the least to own: ₹78,988 over 5 years, price and power together.

After the warranty runs out

Non-inverter: very sturdy, few breakdowns. The usual repair is a capacitor, about ₹1,500 to replace.¹² Inverter: the PCB that drives the compressor is the costly part.¹⁴ Repairing it costs about ₹3,500, and a new PCB costs much more.¹² At 4 hours a day the GTKL50 saves you ₹587 a year in electricity over the GTQ50. One PCB repair uses up about 6 years of that saving. Daikin covers the inverter PCB for 5 years, but that cover does not include handling and fixing charges.⁶

How we worked this out

• Units a year = the AC's BEE label figure × your hours ÷ 1,600. BEE rates every AC for 1,600 hours a year.²
• Label figures for 1,600 hours: GTQ50 1,002 units, GTKL50 880 units, FTKU50 679 units.⁴
• A month counts as 30 days. Prices are citicool.in's prices today, GST included.¹³
• Not in the 5-year sum: installation, piping, gas top-ups and repairs.

Will it still cool on a Delhi afternoon?

Every AC gives less cooling once it gets hot enough outside. Delhi's average hottest afternoon is 45.3°C.⁹ Full cooling holds up to each series' temperature as Daikin specifies; above that we take off 5% for every °C, the same rule our AC calculator uses.¹⁰

At 45.3°C the GTQ50 (non-inverter) and GTKL50 (3 Star inverter) both drop to 89%. Only the FTKU50 still gives full cooling. In Delhi heat, the series matters as much as the type.

Size your room for the hottest day

Side by side

How each kind works inside, with a live explainer: the difference between inverter and non-inverter ACs.

Things people get wrong

Myth: An inverter always saves electricity.

Fact: Only in hours the AC has power to spare. If it can't hold your setting, an inverter runs flat out like a non-inverter, and at full power the GTKL50 3 Star draws more current than the GTQ50 (7.17 A against 5.8 A).¹¹⁵

Myth: An inverter AC runs on my home inverter.

Fact: The name has nothing to do with power backup. "Inverter" is the part that changes the compressor's speed by changing the frequency of its power supply.¹

Myth: Inverter ACs cool slowly.

Fact: Daikin's inverters start at maximum capacity to cool the room fast, then slow down once it is cool.¹⁵

Myth: A 5 Star AC is 5 Star forever.

Fact: BEE star bands are valid for a set period, printed on the label. Comparing ACs from different years? Compare the ISEER number instead.³

Myth: The lower the setting, the better.

Fact: BEE recommends 24 to 26°C, and 24°C is the default on every star-labelled AC since 2020. Moving from 20°C to 24°C saves about 24% of the AC's electricity, says the Ministry of Power. A low setting also makes it likelier the AC never reaches it and runs flat out.⁸⁷

From our service team

Sales and service under one roof. Cooling Delhi since 1990. Authorized Daikin dealer since 2003.

• Our own team installs and services every AC we sell, so we see what goes wrong years later.
• Non-inverter ACs are very sturdy and rarely break down. The usual repair, a capacitor, costs about ₹1,500.
• An inverter has a PCB that drives the compressor. Repairing it after the warranty costs about ₹3,500, and a new one costs much more.
• At about 4 hours a day an inverter saves only a few hundred rupees a year in electricity, so one PCB repair can wipe out years of saving. That is why our AC calculator suggests a non-inverter for light use.

Visit our showroom at South Extension Part-2, New Delhi, to see both kinds running side by side.

Questions people ask

How much electricity does a 1.5 ton inverter AC use?

On the BEE label, the Daikin GTKL50 3 Star uses 880 units over a 1,600-hour year, about 0.55 units an hour on average; the Daikin FTKU50 5 Star uses 679 units over a 1,600-hour year, about 0.42 units an hour on average. The GTQ50 non-inverter uses 1,002, about 0.63 an hour. Hot afternoons use more than the average and mild evenings less.⁴²

Is an inverter worth it if I use the AC 4 hours a day?

Usually not. At 4 hours a day, the GTKL50 3 Star inverter saves about ₹587 a year in electricity over the GTQ50 non-inverter, at ₹8 a unit over 8 months. One PCB repair after the warranty costs about ₹3,500, about 6 years of that saving. The non-inverter rarely breaks down, and its usual repair, a capacitor, costs about ₹1,500.⁴¹²

Does an inverter save on a top floor in Delhi?

Not always. In a 12 × 12 ft top-floor bedroom in Delhi, used 12 to 6 pm on the hottest day of an average year, our room check has the GTQ50 flat out for 2 of the 6 hours and the GTKL50 for 3. Flat out, an inverter cannot turn down, so the GTKL50 uses 8.4 units to the GTQ50's 7.4. The FTKU50, which keeps full cooling to 46°C, uses 5.9. In a middle-floor bedroom at night, every AC keeps up and the inverters save 14 to 34%.¹¹⁵¹⁰

Why can a 3 Star inverter use more than a non-inverter?

At full power, Daikin rates the GTKL50's operating current at 7.17 A and the GTQ50's at 5.8 A; the FTKU50 5 Star is rated at 5.51 A. BEE's ISEER weighs the milder hours most, and an inverter scores well there by turning down. In hours it runs flat out, that advantage is gone.⁵³

Which is better for Delhi summers?

For long hours in a room the AC can keep up with, an inverter. In peak heat the floor, the room and the series matter as much as the type: the GTQ50 non-inverter and the GTKL50 inverter both give full cooling only up to 43°C, while the FTKU50 holds it up to 46°C. Delhi's average hottest afternoon is 45.3°C.¹⁰⁹

Does an inverter AC cool a room faster?

It starts at maximum capacity, and Daikin's 1.5 ton inverter can briefly run up to 1.7 ton, above its rated size. Once the room is cool it slows down rather than switching off.¹⁵¹

What is the warranty difference?

Daikin gives a non-inverter split AC 12 months on the unit plus 4 more years on the compressor. An inverter split gets 12 months on the unit, 4 more years on the PCB and 9 more on the compressor. The extra PCB cover does not include handling and fixing charges.⁶

What does ISEER mean on the label?

Indian Seasonal Energy Efficiency Ratio: the cooling an AC delivers over a year divided by the electricity it uses in that year. Higher is better. BEE works it out over 1,600 hours at outside temperatures from 24°C to 43°C.²³

Do I need a stabiliser with a Daikin inverter AC?

Daikin says you won't need to buy a separate stabiliser with its inverter ACs.¹⁴

Sources

1. Inverter Technology (Daikin India)
2. Indian Seasonal Energy Efficiency Ratio (Vikaspedia, Government of India)
3. Star labelling schedule: the ISEER method, the national bin-hour table and label validity (Bureau of Energy Efficiency)
4. BEE star label figures from the Daikin RA Master Catalogue 2026, shown on each product page (Daikin)
5. Each model's page: rated operating current and cooling range (GTQ50 5.8 A; GTKL50 and GTKC50 7.17 A, 1.4 to 5.3 kW; FTKU50 5.51 A, 1.58 to 5.9 kW) (Daikin India)
6. Product Warranty (Daikin India)
7. BEE notifies new energy performance standards for air conditioners (24°C default), 6 January 2020 (PIB, Ministry of Power)
8. Lok Sabha Unstarred Question 2613 on energy efficiency, 27 December 2018 (Ministry of Power)
9. Climate normals for Palam, New Delhi, as used in our AC calculator (India Meteorological Department)
10. Daikin's full-cooling temperature for each series, and our 5%-per-°C rule above it, as used in our AC calculator (Daikin · Citi Cool engineering)
11. Our AC calculator: Daikin's heat-load method for your room, floor and city (Citi Cool engineering)
12. Repair costs and breakdowns seen by our own service team, October 2026 (Citi Cool)
13. Daikin 1.5 ton AC prices and stock today (citicool.in)
14. Top 10 Reasons to Buy Daikin 5 Star Inverter AC (Daikin India)
15. Daikin Inverter Technology (Daikin India)

More AC questions, answered

• Which ton AC does my room need?: Sized for your city's hottest day, with the right AC from stock.
• How many units does a 1.5 ton AC use?: Your room hour by hour, the label averages by size, and what an AC adds to a Delhi bill.
• What is the difference between an inverter and a non-inverter AC?: Watch both compressors cool a room, see what "inverter" means, and what is different inside, from Daikin's own specs.
• Coming next: 3 Star or 5 Star: is 5 Star worth it?
• Coming next: What temperature should I set my AC to?
• Coming next: VRV or split ACs for a whole home?
• Coming next: How often should an AC be serviced?

Still not sure which one fits your room? Call sales on 77039 00307, or book a ₹99 video call with an engineer, adjusted against your order.