Cost of the same heat: 2 kW of heat for one hour, at the electricity price you chose in the calculator.
Oil radiators, convectors, fan heaters and space heaters turn electricity into heat the same way, so the same heat costs the same with all of them. They differ in how quickly and evenly they warm the room. An air conditioner is a heat pump: from 1 kWh of electricity it gives about 3 to 4 kWh of heat, which is why it's cheaper.
posokaiei.gr