Estimate the running cost of a space heater per hour and month.
Every electric space heater is exactly as efficient as every other: all the electricity becomes heat, so a 1,500 W fan heater, oil-filled radiator and infrared panel all deliver 1.5 kWh of heat per hour of running and cost identically. Claims that one type is cheaper to run refer only to how much the thermostat lets it run — an oil-filled radiator holds heat and cycles less, and a radiant panel warms people directly so the air can be cooler. That cycling is the whole story: at seventy percent duty a 1,500 W heater for six hours a day costs about 6.3 kWh, not 9. The comparison that matters is against central heating, where a heat pump delivers three units of heat per unit of electricity, making a resistance heater roughly three times dearer per unit of warmth.
Space heater running cost
kW = watts / 1000; energy per day = kW x hours x duty / 100; cost per month = energy per day x rate x 30.437; cost per hour running = kW x rate
Portable heaters are a leading cause of home fires. Keep at least one metre of clearance from furniture, bedding and curtains, plug directly into a wall socket rather than an extension lead or power strip, never leave one running unattended or while asleep, and follow the manufacturer's instructions.
Not per kilowatt-hour — all resistance heaters are 100% efficient. It can cost less overall because its thermal mass smooths the cycling and it often runs at a lower duty, but the electricity price per unit of heat is identical.
Only for heating one room while the rest of the house stays cold. Per unit of heat it is the most expensive option available, roughly three times a heat pump and often more than gas, so it wins on zoning, never on efficiency.
Because it is the difference between the nameplate cost and the real one. A well-insulated room may hold temperature at forty percent duty, cutting the bill by well over half against continuous running.