A space heater can be less expensive than central heating if it is used to heat one small room or to supplement the heat in a room. Space heaters are not less expensive or as effective central heating when heating most rooms.
As of 2011, electric space heaters, used about 1,500 kilowatts at full power, as tests by Consumer Reports indicate. Electricity rates vary by state, and space heaters should never be used while household members are asleep. Most heaters are likely to be used about 16 hours per day, and the cost can be calculated by multiplying the hourly kilowatt use by the cost per kilowatt from the local utility service.