Most people choose an air conditioner for heating by the wrong number. They look at the energy class on the label and the capacity in BTU — but those mostly describe cooling. Heating efficiency is hidden in another figure that almost nobody checks: SCOP.
At Svit Komfortu we install air conditioners in Varna, and we see the result of this oversight every winter. So here we’ve ranked the models in our catalog not by price or brand, but by how much electricity they actually use to heat.
Contents
- The three numbers that decide everything
- Ranking: the best air conditioners for heating 2026
- Which model for which situation
- How much electricity heating with an air conditioner uses
- What capacity you need for heating
- 4 mistakes when choosing an air conditioner for heating
- When an air conditioner is no longer enough
- Frequently asked questions
The three numbers that decide everything
Two air conditioners with the same 9,000 BTU and the same price can differ by 30% on your power bill in winter. The difference shows up in three parameters from the technical specifications — and they’re published for every model.
1. SCOP — heating efficiency
SCOP (Seasonal Coefficient of Performance) shows how many kilowatt-hours of heat the unit delivers for every kilowatt-hour of electricity used over the entire heating season. A SCOP of 4.0 means you get 4 kWh of heat from 1 kWh of electricity.
A common mistake is to look at SEER — but that’s the seasonal coefficient for cooling. A model with SEER 8.5 can have a SCOP of 4.0 and not be good for winter.
2. The second letter of the energy class
An air conditioner’s energy class is always double, for example „A+++ / A++“. The first letter is for cooling, the second for heating. That’s the one that matters if you’re buying the unit for winter.
3. Heating operating range
Every air conditioner has a lower outdoor temperature limit down to which the manufacturer guarantees heating. On standard models it’s −15 °C; on cold-climate series (NORDIC, HEAT+, Hyper Heating) it goes down to −25 °C or −30 °C.
For Varna and the Black Sea coast, −15 °C is practically enough. For inland Bulgaria and mountain areas, look for at least −20 °C. Something else matters too: the closer the outdoor temperature gets to the lower limit, the more the heat output drops — a unit rated „down to −15 °C“ is already running well below its nominal output at −12 °C.
Ranking: the best air conditioners for heating 2026
The ranking is by SCOP — the real measure of heating efficiency. All prices and specifications are from our current catalog as of August 2026.
| Model | BTU | SCOP | Class (cool./heat.) | Works down to | Price |
|---|---|---|---|---|---|
| Mitsubishi Heavy SRK25ZSX-WFB | 9 000 | 5,2 | A+++ / A+++ | −20 °C | 1 712 € |
| Daikin Perfera FVXM25B (floor-standing unit) | 9 000 | 4,7 | A+++ / A++ | −20 °C | 1 688 € |
| Nippon NPC 12 T-PRO NORDIC | 12 000 | 4,7 | A+++ / A++ | −25 °C | 499 € |
| Nippon NPC 09 T-PRO NORDIC | 9 000 | 4,6 | A+++ / A++ | −25 °C | 451 € |
| KAISAI NORDIC KNP12 | 12 000 | 4,6 | A+++ / A++ | −30 °C | 1 175 € |
| Daikin Sensira FTXC25E | 9 000 | 4,4 | A++ / A+ | −15 °C | 690 € |
| KAISAI BLACK PRO HEAT+ KRB-09 | 9 000 | 4,0 | A++ / A+ | −15 °C | 700 € |
| TechPoint NPT 09 X-PRO NORDIC | 9 000 | 4,0 | A++ / A+ | −20 °C | 325 € |
The first thing you notice in this table is that price and heating efficiency don’t go hand in hand. The Nippon NPC 09 at €451 has a higher SCOP and a wider operating range than the KAISAI BLACK PRO HEAT+ at €700. That’s a €249 difference in favor of the cheaper unit — with better winter performance.
The full selection is in the category inverter air conditioners, and if you need help choosing, see also our general guide air conditioners for heating.
Which model for which situation
🏆 Best value for efficiency — Nippon NPC 09 T-PRO NORDIC
SCOP 4.6, energy class A+++ / A++, heating down to −25 °C, built-in Wi-Fi, 36-month warranty — for 451 €. This is the model we recommend most often for a bedroom or room up to 21 m² when the air conditioner will also be used in winter. The larger version NPC 12 T-PRO NORDIC covers up to 25 m² with a SCOP of 4.7 at €499.
⚡ Highest efficiency — Mitsubishi Heavy SRK25ZSX
SCOP 5,2 and class A+++ on both counts — this is the top of our catalog. It delivers up to 6 kW of heat at a nominal 9,000 BTU and works down to −20 °C. The price of 1 712 € pays off with heavy use throughout the season and in rooms where the air conditioner is the main heating.
❄️ For the coldest regions — KAISAI NORDIC KNP12
Guaranteed heating down to −30 °C — the widest range in the ranking. If the property is in a mountain area or inland, where temperatures drop below −20 °C, this model is the right choice, with a SCOP of 4.6 at €1,175.
🔥 For the best heating comfort — Daikin Perfera floor-standing unit
Warm air rises. A wall-mounted air conditioner blows it out from a height of 2.3 m and it collects under the ceiling, while your feet stay cold. The FVXM25B floor-standing unit is installed low and spreads heat across the floor — just like a radiator. With a SCOP of 4.7 and class A+++/A++, it’s the most comfortable heating solution, though at a price of €1,688.
💰 Lowest budget — TechPoint NPT 09 X-PRO NORDIC
For 325 € you get a SCOP of 4.0 and operation down to −20 °C. It’s no efficiency champion, but it’s an honest unit for year-round use and still four times more economical than an electric convector heater. See the model or the more powerful NPT 12 X-PRO NORDIC for €345.
How much electricity heating with an air conditioner uses
Here’s why SCOP isn’t an abstract number. Take a room of about 25 m² that needs roughly 2,500 kWh of heat over one heating season. With electricity at about 0,15 €/kWh the bill looks like this:
| Heating method | Efficiency | Electricity per season | Cost |
|---|---|---|---|
| Electric convector / radiator | COP 1,0 | 2 500 kWh | ≈ 375 € |
| Air conditioner SCOP 4.0 (TechPoint, KAISAI HEAT+) | SCOP 4,0 | 625 kWh | ≈ 94 € |
| Air conditioner SCOP 4.6 (Nippon NORDIC, KAISAI NORDIC) | SCOP 4,6 | 543 kWh | ≈ 82 € |
| Air conditioner SCOP 5.2 (Mitsubishi Heavy) | SCOP 5,2 | 481 kWh | ≈ 72 € |
This calculation is approximate: actual consumption depends on insulation, the desired temperature, how often you air the room and how many hours a day the unit runs. For a more detailed calculation, see air conditioner power consumption.
What capacity you need for heating
There’s a catch here that costs money. Standard BTU tables are calculated for cooling. When heating, the unit works in less favorable conditions — the colder it is outside, the less heat it delivers.
- Bedroom up to 20 m² → 9 000 BTU
- Living room 20–35 m² → 12 000 BTU
- Large room 35–60 m² → 18 000 BTU
If the air conditioner will be the main heating, rather than a supplement to central heating or a stove, get a model one step more powerful than the one recommended for cooling. A room for which 9,000 BTU is enough in summer will be served more comfortably in winter by 12,000 BTU.
For an exact calculation for your room, use how many BTU you need. And if you have several rooms, also take a look at multi-split systems — one outdoor unit serves up to five indoor units.
4 mistakes when choosing an air conditioner for heating
- Looking only at the first letter of the energy class. The „A+++“ on the label is usually for cooling. For winter, the second letter is what counts.
- Confusing SEER with SCOP. A high SEER doesn’t guarantee efficient heating — they’re two independent figures.
- Ignoring the lower temperature limit. A unit rated „down to −15 °C“ doesn’t stop at −16 °C, but its heat output drops significantly well before that.
- Capacity calculated from summer tables. If the air conditioner is the main heating, go one step up.
If you’re not sure where your case fits — our installation team will do a site visit and calculate on the spot. We work with customers in Varna and the region.
When an air conditioner is no longer enough
An air conditioner heats one zone — the room where it’s installed. That makes it an excellent solution for an apartment, a single room or as a supplement to existing heating. There are cases, however, when it’s the wrong tool:
- A multi-story house that needs an even temperature throughout.
- A property with an existing radiator or underfloor hydronic heating system.
- A need for domestic hot water, not just heating.
In these cases the solution is an air-to-water heat pump. It works on the same physical principle as an air conditioner — it takes heat from the outdoor air — but delivers it to a water-based system: radiators, underfloor heating and a hot water tank. It serves the whole home from one system.
And if you bought your air conditioner mainly for summer and wonder how to use it in winter too — read air conditioners for cooling and types of air conditioners.
Not sure which model will heat your room economically?
Contact Svit Komfortu for a free consultation — we’ll calculate the capacity you need based on floor area and insulation, pick a model with the right SCOP and give you a clear final price including installation.
Frequently asked questions
What is the best air conditioner for heating?
For efficiency, the leader is the Mitsubishi Heavy SRK25ZSX with a SCOP of 5.2 and class A+++/A+++. For value, the best is the Nippon NPC 09 T-PRO NORDIC — SCOP 4.6, class A+++/A++, heating down to −25 °C, for about €451.
What is SCOP and why does it matter for heating?
SCOP shows how many kWh of heat an air conditioner delivers for every kWh of electricity used over the entire heating season. A SCOP of 4.6 means 4.6 kWh of heat from 1 kWh of electricity. The higher the SCOP, the lower your winter bill. SEER describes cooling and shouldn’t be confused with SCOP.
Down to what temperature does an air conditioner heat?
Standard inverter models heat down to −15 °C, while cold-climate series — NORDIC and HEAT+ — go down to −25 °C or −30 °C. For Varna and the Black Sea coast, −15 °C is practically enough; for inland Bulgaria, look for at least −20 °C.
How much does heating with an air conditioner cost per month?
For a room of about 25 m² with a SCOP 4.6 air conditioner, seasonal consumption is roughly 543 kWh, or about €82 at an electricity price of €0.15/kWh. The same room with an electric convector heater would cost about €375 for the season.
Is a cheaper air conditioner worse for heating?
Not necessarily. The Nippon NPC 09 T-PRO NORDIC at €451 has a SCOP of 4.6 and works down to −25 °C, while a €700 model from another series has a SCOP of 4.0 and works down to −15 °C. SCOP and the temperature range are what count, not the price tag.
Which air conditioner should I choose if it’s the main heating in my home?
Choose a model with a SCOP above 4.5, an operating range down to at least −20 °C and capacity one step above what’s recommended for cooling the same area. For rooms with large windows, consider a floor-standing unit — it spreads heat across the floor instead of under the ceiling.
When is a heat pump better than an air conditioner?
An air-to-water heat pump is better suited to a whole house, a property with radiators or underfloor hydronic heating, and when domestic hot water is also needed. An air conditioner heats one zone and is optimal for an apartment or a single room.
For a whole house rather than individual rooms, the solution is an air-to-water heat pump. Real prices by floor area are in Heat pump for a house — prices.
