Short answer: what do you actually pay?
For a typical Varna apartment with a 12000 BTU A++ inverter AC, the electricity cost for a summer month is 50-110 BGN(~25-55 EUR). If you run it 6-8 hours a day at correct settings (25-26°C), the bill is at the lower end. If you hold 22°C around the clock — at the top, and beyond.
This article gives concrete numbers for every unit type: 9 000, 12 000, 18 000, 24 000 BTU. We show the real formula, Varna tariffs, and 8 ways to cut up to 40% off the bill without sacrificing comfort.
The calculation formula
Consumption is computed by a simple formula:
Cost (BGN) = Power (kW) × Hours × Price (BGN/kWh) ÷ SEER
Where:
- Power in kW — for a 12000 BTU unit cooling capacity is ~3.5 kW, but actual electrical consumption is significantly less due to SEER.
- SEER (Seasonal Energy Efficiency Ratio) — how much "cooling" you get per kW of electricity consumed. A modern A++ inverter has SEER 6.5-8.5. That means for 3.5 kW of cooling you actually spend 0.4-0.55 kW of electricity.
- Electricity price — in Varna for household clients ~0.22-0.30 BGN/kWh day rate, ~0.13-0.18 BGN/kWh night rate (free market since 2025 — actual prices depend on your supplier).
Table: cost in BGN by unit type
Real monthly cost at ~0.27 BGN/kWh day rate, normal usage, A++ inverter. Numbers are pure "AC electricity", not the whole bill.
| BTU | For area | 4h/day | 8h/day | 12h/day |
|---|---|---|---|---|
| 9 000 | up to 20 m² | ~25 BGN | ~50 BGN | ~75 BGN |
| 12 000 | 20-30 m² | ~35 BGN | ~70 BGN | ~105 BGN |
| 18 000 | 30-45 m² | ~55 BGN | ~110 BGN | ~165 BGN |
| 24 000 | 45-60 m² | ~75 BGN | ~150 BGN | ~225 BGN |
Note: running Sleep mode at night on a night-rate meter brings real numbers down by 30-40%. Numbers above assume day rate.
Why SEER matters more than BTU for the bill
Two ACs with the same 12000 BTU rating can have a 2x difference in consumption. Why? Because SEER measures efficiency.
| Energy class | SEER | Cost at 8h/day (12k BTU) | Per season (3 months) |
|---|---|---|---|
| A (old) | 3.2 | ~130 BGN | ~390 BGN |
| A+ | 5.6 | ~85 BGN | ~255 BGN |
| A++ | 7.0 | ~70 BGN | ~210 BGN |
| A+++ | 8.5+ | ~55 BGN | ~165 BGN |
Difference A vs A+++ is 225 BGN per season for a single unit. If you run summer Cool 3 months + winter Heat for 4 more months, the difference is 400-600 BGN per year. So the price premium (200-400 BGN) pays off in 1-2 years.
Real example: apartment in Chayka, 70 m²
Two-room apartment on the 5th floor in Chayka, south-facing. One Daikin 12000 BTU A++ AC in the living room. Family of 3, summer use:
- Morning 07:00-09:00 (2h) before work: Cool 25°C
- Evening 18:00-22:00 (4h): Cool 25°C + Sleep last hour
- Night 22:00-07:00 (Sleep mode at 26°C): ~9h in economy mode
Total ~12h real runtime daily, 9 of them in Sleep (~50% power). Effective "full" hours: ~7.5.
Result: ~65-80 BGN/month pure AC consumption. For a 3- month June-August season — about 200-240 BGN. Without AC in a hot Chayka concrete block in August — not an option.
Summer vs Winter — which costs more
Surprisingly, most Varna ACs cost more in summer, not winter. Reason:
- Summer: heat is 30-36°C, gap with target (25°C) = 5-11°C. Long runtime.
- Winter: rarely below 0°C, usually 5-10°C. Gap with target (21°C) = 11-16°C. Bigger gap, but Heat mode on a heat pump is more efficient (COP 3.5-4.5). With Varna's mild winters, at similar hours winter actually ends up cheaper.
Real rule: in mild months (May, September, October) AC is dramatically cheaper — runs briefly and in Dry mode. Cost drops to 15-30 BGN/month.
Electricity tariffs in Varna (2026)
Varna falls under "Elektrorazpredelenie Sever" (formerly EnergoPro). Since July 2025 household clients can choose the free market. Indicative prices:
- Day rate (06:00-22:00 for two-rate meters): ~0.22-0.30 BGN/kWh.
- Night rate (22:00-06:00): ~0.13-0.18 BGN/kWh.
- Single rate (standard meter): ~0.22-0.26 BGN/kWh.
Real prices vary by supplier and plan. We recommend checking your invoice — the actual kWh price is on the back. If you have a two-rate meter and use AC mostly at night (Sleep mode), real cost is ~30% lower than the tables.
8 ways to cut the bill by up to 40%
- Set temperature to 25-26°C instead of 22°C. This alone saves 30-40%.
- Activate Sleep mode for the night. The unit optimizes itself.
- Annual maintenance. Clogged filter = -25% efficiency = -25% of your money.
- Use Dry mode in mild days instead of Cool. 50% lower consumption.
- Close blinds and curtains on south-facing windows during the day. Reduces thermal load.
- Use night rate — night cooldown to 22°C, then Sleep, then morning off.
- Don't run AC in an empty room "just in case". AC doesn't "hold" temperature — it responds to need.
- Replace old A-class units with A++ inverter. Pays off in 1-2 seasons.
Inverter vs non-inverter — real annual difference
A non-inverter AC works on "on/off" principle — once it reaches target temperature, it cuts the compressor. Then temperature rises, it restarts. Every start consumes a large surge of electricity (motor inrush current).
An inverter modulates the compressor frequency — runs at lower power continuously. Savings: 30-40% per year.
For a typical Varna apartment, year-round inverter vs non-inverter difference:
- Non-inverter A: ~650-800 BGN/year per unit
- Inverter A++: ~380-480 BGN/year
- Savings: ~270-320 BGN/year
Over 7-10 years of unit life — 2000-3000 BGN saved. That's more than the cost of the AC itself.
What to do now
First: lower the temperature from current to 25-26°Cand enable Sleep mode at night. That's free 30-40% savings this month.
Second: if your AC is A-class (bought before 2018) — calculate if it makes sense to replace it. Often the difference pays off in 2-3 seasons. You can ask our AI consultant on the site for a specific recommendation for your situation.
Third: if you haven't done maintenance this year — book it. 25% of nothing can't be fixed by any setting. Request via the form on the site or call us.