Why don't we turn on the air conditioner instead of the heater during the winters? During winters  the temperature at my area  drops to around $5° \text C$. I feel comfortable around $25° \text C$. To stay warm, we usually turn on the heater instead of air conditioner even tough I can set the temperature of the air conditioner to the temperature I am comfortable at. So shouldn't the AC keep me warm during winters?
A heater nearly consumes the same amount of power as an AC (around $1.5 \;\text{kW}$) , so I was wondering what is the point of having two different appliances for two different seasons?
 A: You are misunderstanding the way heaters and air conditioners work, as separate appliances.
If your home is at 5 degrees C and you set the air conditioner control to 10 degrees C, the air conditioner will not turn itself on until the temperature in your house exceeds 10 degrees C. This is because the AC unit itself does not contain a heater.
Similarly, if your home is at 10 degrees C and you set the heater control to 5 degrees C, the heater will not turn itself on until the temperature in your house falls below 5 degrees C. This is because the heater itself does not contain an AC unit.
If your home has a combined heating and air conditioning system installed, then you set the control to the temperature you prefer. If the temperature exceeds that setting, then the AC is turned on. If the temperature falls below that setting, then the heater is turned on.
The most modern and efficient combined heat/AC systems today are called heat pumps and they can automatically switch back and forth between heating or cooling your home.
A: Because in colder temperatures a standard air conditioner's compressor will not come on, only the fan will be on so it will not heat your house. Some air conditioners will also act as a heat pump, which acts in reverse of the summer AC mode. It reverses the freon flow so the inside coil becomes the condenser coil instead of the evaporator coil. This causes it to blow warm air inside to heat the house.
