If you have been asking this question, How to use AC as heater in winter, it is a common question. Many of us already own an inverter or split ACs, and we don’t want to pay extra for room heaters. The good thing is that if your AC has a HEAT mode or ☀️ sun symbol on the remote, it can heat your room just like a heater – in some cases, even more effectively.
I used this method last winter at my home, and honestly, it worked really well for small rooms. However, there are a few things that you need to know before you turn on the heating mode.
Can Every AC Heat the Room?
Not really. Only certain types can:
| AC Type | Works for Heating? |
|---|---|
| Split/Inverter AC with Heat Mode | ✅ Yes |
| HVAC / Heat Pump Systems | ✅ Yes |
| Window AC (Cooling Only) | ❌ No |
| AC Remote Shows “HEAT” or ☀️ | ✅ Most likely |
| Only Cool, Fan, Dry Options | ❌ No Heating Feature |
If your AC remote doesn’t show HEAT mode or a sun icon, that means your AC is designed only for cooling.
Also Read: Do Air Conditioners Purify Air?
How to use AC as heater in winter (Simple Guide)
Using the Remote
- Switch on the AC using the Power button.
- Press the Mode button repeatedly until you see HEAT or ☀️ symbol on the display.
- Set the temperature between 24°C to 26°C. This feels cozy without making the room too stuffy.
- Wait for 1–3 minutes. At first, the air might feel cold – don’t worry, the Air Conditioner is reversing its cycle.
- Turn on Swing mode to evenly spread warm air across the room.
How Does It Actually Heat the Room?
An AC with a heating mode acts like a heat pump. This means that instead of consuming electricity to generate heat (as coil heaters do), it draws heat from the outside air and moves it indoors. Even in winter, there is some heat energy in the air—your AC just moves it.
This is the reason why split and inverter ACs tend to consume less electricity than regular electric heaters, especially in small, closed rooms. In my case, the increase in my bill was not as significant as it would be with a rod or blower heater.
Also Read: Air Cooler vs Air Conditioner
Best Temperature Settings for Indian Homes
| Weather Condition | Ideal Temperature Setting |
|---|---|
| Mild Winter Days | 23–24°C |
| Cold Nights (North India) | 24–26°C |
| Very Cold (Shimla, Kashmir) | 26–27°C + Blanket |
Keeping it above 27°C usually doesn’t warm faster – it just increases electricity use.
Tips to Make Heating Faster and Save Power
- Shut all doors and windows tightly.
- Cover small gaps using cloth or tape to prevent warm air from escaping.
- Use thick curtains or door draft stoppers if possible.
- Clean AC filters every 2–3 weeks for better airflow.
- Turn on the ceiling fan at a low speed to gently circulate the warm air downward, as warm air naturally rises.
- Choose a smaller room if you stay in a large house or joint family — it heats faster and uses less power.
Also Read: Can Low Voltage Damage Air Conditioner?
Pros and Cons of Using AC for Heating
| ✅ Benefits | ⚠️ Things to Keep in Mind |
|---|---|
| No need to buy a separate heater | Doesn’t work on older or window ACs |
| Warm air spreads evenly in the room | The outdoor unit may frost in extreme cold |
| Safer – no burning coils or suffocation | Works best in well-sealed rooms |
| Can be energy-efficient compared to electric heaters | Very low outside temperatures may reduce performance |
Realistic Expectations (Important)
- Works great for small to medium-sized rooms.
- In extremely cold places (below 5°C), the outdoor unit may develop frost, and heating can slow down.
- Some ACs automatically activate defrost mode – a “df” symbol may appear, and warm air stops temporarily. It’s normal.
FAQ
How do I turn my AC into a heater?
If your AC has a heat mode or sun symbol on the remote, then you can turn it into a heater. Hit the Mode button until you see HEAT or ☀️ icon, then set the temperature to about 24–26°C. After that, wait for 1–3 minutes—warm air will start blowing once the compressor reverses its cycle.
How to set AC temperature for heating in winter?
For Indian winters, the perfect temperature for AC heating is 24–26°C. This range provides comfort while it doesn’t overloading the compressor or increasing electricity bills. It’s a good idea to avoid setting the temperature higher than 27°C—your AC will draw more power but will not heat up quicker.
What is the 3-minute rule for AC?
The 3-minute rule suggests that you should not turn your AC on straight after turning it off. The compressor will take a minimum of 3 minutes to equalize its internal pressure. Turning it back on too early could lead to compressor damage, a decrease in its life span, and increased energy use.
Which mode of AC is best in winter?
If your air conditioner is equipped with the Heat Mode (☀️ icon) feature, then you can use it in the winter. During heat mode, the AC acts like a heat pump—taking the heat from the outside air and putting it into the room. Do not use the cool, dry, or fan modes in the extreme cold since these modes do not provide any heating at practically.
Can I run my AC on dry mode all day?
The intention of dry mode is only to take out the excess moisture in the air, not to warm the room. An all-day run in winter would make the air too dry and harsh for skin and throat. Instead of dry mode, it is better to use heat mode for warming up and use dry mode for very short periods only when the humidity is high.
Final Thoughts – How to Use AC as Heater in Winter
If your AC is equipped with heat mode, you actually do not have to purchase a room heater to heat your room. Just ensure that the room is tightly closed, set the temperature to about 24–26°C, and let it run for a few minutes.
I have been following this method for 2 winters now, and it has really worked well for bedrooms and small living areas.
