Action Line: Space heaters aren't for whole-house heating
BY PHIL MULKINS World Action Line Editor
Tuesday, January 01, 2013
1/01/13 at 2:36 AM
Electric space heaters are for "spot heating" and are not practical for whole-house heating. They're for that one family member who always needs a personal heat source so the rest of the family can be comfortable at a 65-degree furnace thermostat setting in the winter.
American Electric Power-Public Service Company of Oklahoma's current kilowatt-hour fee is $0.08588, said company spokesman Ed Bettinger. A radiant electric heater running at 1,500 watts per hour for 24 hours uses 36,000 watts. A "kilowatt-hour" is the use of 1,000 watts in one hour. Dividing 1,000 watts into 36,000 watts is 36 kilowatt-hours. At 8.588 cents per kwh the heater would cost $3.09168 per day to operate - times 30 days in a month is $92.75 (a hefty bill for a little space heater).
John Staires, electrical inspections supervisor for the city of Tulsa, said most Tulsa household electrical circuits now are capable of carrying 20 amps of power. Even though they are capable of 20-amp service, by code, any one cord-connected appliance cannot exceed a maximum of 80 percent of the circuit rating - 16 amps - to avoid pushing the circuit to its maximum capacity and tripping its breaker. The maximum number of watts that can be supplied by a receptacle is determined by multiplying line voltage (120 volts in Tulsa) by the amps (16 amps) for a total of 1,920 watts. Modern-day electrical heaters run at 1,500 watts - meaning only 420 watts remain available on that circuit, once the heater is running.
However, most circuits have multiple wall receptacles, over their lengths through the house, some powering 4 wall receptacles and two ceiling lights, etc. If the ceiling light fixtures each power one 60-watt bulb (120 watts) and three of the receptacles each power a 100-watt appliance (300 watts) that would take 420 watts - meaning the circuit is right at its 80 percent usage maximum with the heater included. This underscores the need for running the electric heater as the only electrical device on that circuit.
"Ideally, the heater should be on a 20 amp circuit (one with no other power requirements) and be served by a 20 amp receptacle," Staires said. "There are still some 15 amp circuits in older Tulsa homes and these should not be used for electrical heaters, as the 80 percent permitted maximum on 15 amps is 1,440 watts - 60 watts shy of being adequate. Buy only heaters with listing marks from nationally recognized testing labs: UL, ETL or CSA - to ensure the heater was tested to conform to a safety standard."
A house fire Dec. 20 in the Carter County town of Wilson killed a mother, her 7-year-old daughter and 4-year-old son. Three space heaters were known to be operating in the home at the time of the fire.
Never leave one unattended or running while sleeping. Half the deaths and one-third of the injuries from electric heater fires, nationally, occur at night when people are asleep with the heaters on. Use only those with tip-over shut-off switches. Electric space heaters should not be used with extension cords, but if you must, buy a 12-amp or better (No. 12 or No. 13 gauge) cord for a 1,500-watt heater. Keep heaters three feet or more from furniture, bedding and other flammables.
Original Print Headline: Space heaters not for entire house
Phil Mulkins 918-699-8888
A Home Depot customer eyes the portable electric heaters in downtown Tulsa on Dec. 19 as evening temperatures fell steadily into the 30s. Even though the heater box in the foreground says "small," the term applies to the case in which the heating element resides. There's nothing "small" about a 1,500-watt heater. That's as big as they come in off-the-shelf portable heaters and even the small ones should be provided their own dedicated 20-amp circuits with no other lights or appliances attached. Electric heaters do cause home fires when placed closer than 3 feet to flammable materials and such heaters should be turned off at bedtime. JAMES GIBBARD / Tulsa World