I asked ChatGPT, how can I prevent my electricity bill from shooting up in Delhi's blistering heat

As Delhi swelters with day-time temperatures reaching 43 degrees Celsius and prolonged heat wave conditions, I ask ChatGPT to devise a strategy that prevents my electricity bill from shooting up this summer.

Its response includes choosing the right air conditioner (AC), checking its power ratings, and the optimum temperature that can effectively cool your room without burning a hole in your pocket. It also answers the contended question — fans on or off with AC. Here's what it said:

The ChatGPT Prompt

I am a working professional living in Delhi. It is a household of 2 people. On most days, I work from home. This summer, Delhi's heat has been intense, with the heat wave lasting for two weeks and maximum temperature crossing 43 degrees on most days of the week. In fact, the temperature remains above 40 degrees till 7pm in the evening, and only falls till 36-37 degrees by night. The minimum temperature ranges around 35 degrees celsius in the wee hours. This means, the air conditioner is on non-stop during the day, as well as during the night. Electricity per unit ranges from ₹3 per unit and goes on till ₹8 per unit, depending on usage (as in the table in the attached image).

Devise a strategy so that I can keep my electricity bill from shooting up this season. What kind of air conditioners shall I use — window or split, what kind of power rating shall I check before buying, how can I optimise usage so that room temperature is a comfortable 25 degrees celsius. Shall I use alternatives such as tower ACs or coolers?

ChatGPT's most practical strategy:

First Priority: Buy the Right AC

Best Choice: Inverter Split AC

Avoid:

• Non-inverter ACs
• Old window ACs
• Portable/tower ACs

Choose:

• 5-star inverter split AC
• Copper condenser
• Variable-speed compressor

Why:

In Delhi’s current climate, ACs run almost continuously. Inverter ACs reduce compressor cycling and consume dramatically less electricity during long-duration operation.

A non-inverter AC may consume: 1.6–2.2 units/hour

A modern inverter split AC at stable temperature may average: 0.7–1.1 units/hour after initial cooling.

That difference becomes enormous over 15–18 hours/day.

2. Window vs Split AC: Split AC Wins Clearly

Window AC

Pros:

• cheaper upfront
• easier installation

Cons:

• noisier
• poorer insulation
• higher power draw
• less efficient during continuous operation

Split AC

Pros:

• quieter
• better airflow
• better inverter efficiency
• faster cooling
• lower long-term bill

For your use case (WFH + overnight use): Split inverter AC is the financially smarter option despite higher purchase price.

3. What Capacity Should You Buy?

Bigger AC ≠ better. Oversized ACs cool quickly but cycle inefficiently. For most Delhi bedrooms/living rooms: 1.5 ton inverter AC is ideal.

4. Most Important Spec: ISEER Rating

Do not focus only on “5-star.”

Look for: ISEER (Indian Seasonal Energy Efficiency Ratio) rating above 5

Higher ISEER = lower electricity usage over long Indian summers.

Examples:

• Good: 5.0+
• Excellent: 5.2–5.5

5. The Biggest Mistake People Make: Setting AC at 20–22°C

In Delhi’s 43°C heat, this forces the compressor to work continuously.

Instead, the ideal setting would be: 25–26°C + ceiling fan

This is the sweet spot. Why?

• Fan improves perceived cooling by 3–4°C
• Compressor rests more often
• Huge reduction in units consumed

At 25°C with a fan:

• comfort feels like 22–23°C
• power consumption can drop 20–35%

6. Use Ceiling Fan WITH AC

Very important.

Many people switch off fans while running AC. Wrong strategy.

A fan:

• distributes cool air faster,
• removes hot pockets,
• lets you raise thermostat temperature.

Result:

• less compressor runtime
• lower bill

7. Cool the Room, Not the House

Keep:

• doors shut
• curtains drawn
• sunlight blocked from west-facing windows

Delhi’s afternoon sun can raise indoor temperature massively.

Use:

• blackout curtains
• reflective window film
• bamboo blinds
• thermal curtains

This can reduce cooling load by 10–20%.

8. Tower ACs & Portable ACs: Avoid

Portable/tower ACs are usually terrible for Indian heat.

Problems:

• inefficient
• noisy
• exhaust hot air badly
• consume high power
• poor cooling in 43°C weather

They often consume almost as much electricity as split ACs while cooling far worse.

Not recommended.

9. Air Coolers: When They Work

Coolers work only when humidity is low.

Delhi:

• May/early June: decent for coolers
• Monsoon period: poor performance

A desert cooler can reduce electricity costs substantially: 150–250 watts vs 1200–1800 watts for AC. But:

• they won’t maintain 25°C in extreme heat
• comfort drops sharply at night during humid conditions

Best strategy:

• cooler during mornings/evenings
• AC only during peak afternoon/night

10. Smart Hybrid Strategy (Best for Bills)

Morning (before 11am): fan + ventilation

Afternoon peak heat:

• AC at 25–26°C
• fan on low speed

Evening: cooler/fan if outdoor temp falls

Night

• AC sleep mode
• timer after 3–4am if possible

This alone can reduce monthly units dramatically

11. Sleep Mode Is Extremely Valuable

Use:

• sleep mode
• eco mode
• AI mode

At night your body needs less cooling.

AC gradually raises temperature by 1–2°C:

• saves electricity
• still feels comfortable

12. Clean Filters Matter More Than People Think

Dirty filters can increase consumption by: 5–15%

Clean every: 2–3 weeks in Delhi dust

13. Understand the Tariff Trap

The real danger: once your total monthly units rise sharply, much more of your consumption falls into expensive slabs.

An inefficient AC setup can push a Delhi household from:

350–450 units

to

900–1300 units

That can nearly double the bill.

14. Most Cost-Effective Setup For You

For your exact situation:

Recommended Setup

Bedroom

• 1.5 ton 5-star inverter split AC
• thermostat at 25–26°C
• ceiling fan on low

Work Room

If separate:

• use fan + cooler first
• AC only during afternoon

Home Improvements

• blackout curtains
• door sealing
• reflective window film

15. One Counterintuitive Truth

Keeping the AC at 24–26°C continuously is often cheaper than repeatedly turning it on/off at 20–21°C. This is because: restarting cooling from very high room temperatures is energy-intensive.

Steady-state cooling is more efficient.

Final Recommendation

If buying today:

• Buy a 5-star inverter split AC
• Prefer high ISEER models
• Size correctly (likely 1.5 ton)
• Use at 25–26°C with fan
• Avoid portable ACs
• Use coolers selectively
• Reduce sunlight entry aggressively

That combination usually gives the best balance between:

• comfort,
• survivability in Delhi heat,
• and preventing electricity bills from exploding.

Disclaimer: This story is intended solely for educational and informational purposes and is based on an AI-generated response. The views, opinions, or recommendations expressed do not reflect those of Mint.