In short. At home by day set 21–22 °C, at night in the bedroom 18–20 °C. When you go out for the day, do not switch the unit off — turn it down to 17–18 °C. Each degree lower is about 5 % of the heating electricity: if the unit heats the flat for about 1,490 lei a month, two degrees save about 150 lei. And do not set 30 °C “to warm up faster” — it will not be faster.
How many degrees to set
| When | What to set on the remote |
|---|---|
| Daytime, at home | 21–22 °C |
| Night, in the bedroom | 18–20 °C |
| Children’s room | 20–22 °C |
| Out at work for the day | 17–18 °C — do not switch off |
| Away for several days | “+8 °C” mode if it has one, or the minimum of 16–17 °C |
These are the numbers on the remote. How they relate to what you feel is below, in the section about the sensor.
Why not 30 °C
While the room is colder than the set temperature, an inverter unit already runs at full power. The number on the remote is not “heating strength” but the temperature to heat to. Set 30 °C and the unit will not warm the room faster: it simply will not stop at 22 °C, overheats the air and uses extra power. Set the temperature you actually want straight away.
What each degree saves
A home loses heat faster the bigger the difference between the room and outdoors. Over a Chișinău winter it is about zero outside on average, so at 21 °C indoors each degree is roughly 1/21 of the heat, about 5 %.
Example: a flat that needs as much heat as 150 m³ of gas would give in a month. The air conditioner produces it for about 1,490 lei (tariff 3.56 lei per kWh). Setting 20 °C instead of 22 °C saves about 150 lei a month. A detailed calculation is in How much heating with an air conditioner costs per month.
Switch it off or not when you go out
- For a day — do not switch off, turn it down to 17–18 °C. If you switch it off, walls and furniture cool down, and in the evening the unit runs at maximum for a long time to warm them back up.
- For several days — use the “+8 °C” (standby heating) mode if it has one. It keeps the flat from freezing and uses almost no power. ZEUS J-Smart and M-Pro, MDV iERA and Integra Pro, for example, have this mode. If yours does not, set the minimum temperature on the remote, usually 16–17 °C.
Why the remote says 21 °C but it feels cool
The unit measures the air temperature where it is, under the ceiling. Warm air rises, so it is warmer there than near the floor and the sofa — the difference can be 1–2 degrees. What to do:
- set one degree higher on the remote;
- point the louvres down towards the floor: the warm air will rise by itself;
- turn on I Feel or Follow Me if it has it: then the unit uses the sensor in the remote, next to you;
- do not block the indoor unit with curtains or furniture.
What else helps heat for less
- Clean filters. In the heating season rinse them once a month: a clogged filter cuts output and raises the bill.
- Fan speed on “Auto”. The unit picks the speed itself: fast while it is cold, quiet once the room is warm.
- Closed doors. One unit heats its own room; with doors open the heat spreads through the flat and it runs longer.
- Humidity 40–60 %. Any heating dries the air. If your throat and skin feel dry, a humidifier helps — and at normal humidity 21 °C feels warmer.
If the unit sometimes stops blowing warm air for 5–10 minutes in frost, that is the outdoor unit defrosting, and it is normal. Why it happens is in Why an air conditioner does not blow warm air straight away in winter.
Before the season
A unit that cooled all summer is worth cleaning and checking before heating: a dirty heat exchanger heats worse. Winter preparation costs 1 200 lei: cleaning plus a check of heating, defrost and drainage. And if you do not yet have an air conditioner that heats, models that heat in frost down to −25…−35 °C are in Air conditioners with heating.
Approximate calculation: Premier Energy tariff 3.56 lei/kWh (ANRE, from 02.04.2026), seasonal COP 3, average Chișinău winter temperature around 0 °C. Real savings depend on insulation, floor and model.
