If you studied science in high school, you'd have learnt of the Carnot cycle. This "law" governs the efficiency of our airconditioners. Unfortunately, airconditioner capacity is still measured using archane units - tonnage or British Thermal Units - making it hard for ordinary folk to understand how large or efficient their AC is.
A 1.5 ton AC delivers 5.2kW of cooling. The efficiency of ACs sold in India is pasted on top of the AC by the BEE. An 5 star rated AC has an ISEER of 4.5, which means it consumes 5.2kW÷4.5 = 1.16kW of electricity when cooling your room at the rate of 5.2kW. That's just 1.16 units of electricity per hour.
Now compare this to heating. When you run a 1kW heater, it consumes 1kW of electricity (1 unit of electricity consumed per hour) and gives you 1kW of heat. If, instead, you had purchased an AC that both heats and cools (what is then called a heat pump, not an airconditioner), then the same 1kW of electricity would get you 4.5kW of heat†. So what you are now doing is - instead of using the joule heating properties of the metal coil in your heater, you are using the gas laws and the Carnot cycle to tremendously improve the efficienty of your heater.
Countries like Australia and the US are doubling down on replacing inductive or natural gas based space and water heaters with heat pumps. And countries like Taiwan are doubling down on manufacturing this kind of equipment: https://www.taiwantrade.com/product/hp-100-1766979.html
But honestly, making something like this is not hard. It is, after all, an airconditioner running backwards.
† Of course, nobody can handle that much heat blowing into a room, which is why you also need variable speed ACs - where the compressor doesn't just turn on and off at full speed, but instead reduces its speed to provide the optimal level of cooling. Vendors often call such products inverter ACs.
A 1.5 ton AC delivers 5.2kW of cooling. The efficiency of ACs sold in India is pasted on top of the AC by the BEE. An 5 star rated AC has an ISEER of 4.5, which means it consumes 5.2kW÷4.5 = 1.16kW of electricity when cooling your room at the rate of 5.2kW. That's just 1.16 units of electricity per hour.
Now compare this to heating. When you run a 1kW heater, it consumes 1kW of electricity (1 unit of electricity consumed per hour) and gives you 1kW of heat. If, instead, you had purchased an AC that both heats and cools (what is then called a heat pump, not an airconditioner), then the same 1kW of electricity would get you 4.5kW of heat†. So what you are now doing is - instead of using the joule heating properties of the metal coil in your heater, you are using the gas laws and the Carnot cycle to tremendously improve the efficienty of your heater.
Countries like Australia and the US are doubling down on replacing inductive or natural gas based space and water heaters with heat pumps. And countries like Taiwan are doubling down on manufacturing this kind of equipment: https://www.taiwantrade.com/product/hp-100-1766979.html
But honestly, making something like this is not hard. It is, after all, an airconditioner running backwards.
† Of course, nobody can handle that much heat blowing into a room, which is why you also need variable speed ACs - where the compressor doesn't just turn on and off at full speed, but instead reduces its speed to provide the optimal level of cooling. Vendors often call such products inverter ACs.