MARSHFIELD, Mo. –Buyers trying to reduce winter heating costs should closely examine claims by manufacturers of infrared space heaters, said a University of Missouri Extension natural resource engineering specialist.

“Portable box-style infrared heaters are being promoted heavily in stores and in advertisements,” said Bob Schultheis. Some manufacturer claims may be misleading.

One claim is that these space heaters can slash heating bills by up to 50 percent.

“This is possible if you turn the thermostat in your house down and only use the space heater to heat the room you are in,” he said. “The problem is when you move to a different room, you need to bring the space heater with you.”

Another problem is that lowering the heat to the rest of the house too much can cause frozen pipes and excessive condensation on walls and ceilings.

Some manufacturers say their products heat up to 1,000 square feet for pennies a day.

A well-insulated, 1,500-square-foot home will require at least 70,000 BTUs per hour to heat the entire house, Schultheis said. Infrared heaters typically operate on 110 volts and use 1,585 watts of power for maximum output, which works out to 5,410 BTUs per hour. If electricity costs 9 cents per kilowatt-hour and the heater runs six hours per day, it would cost about 86 cents per day just to heat a single 10-by-12-foot room with an infrared heater.

A geothermal heat pump could heat the whole house for that amount of money, Schultheis said.

From a safety standpoint, a 1,585-watt heater will draw more than 14 amps of current, so it will need to be on a separate electrical circuit from other loads.

Another claim is that infrared heaters do not remove oxygen or humidity from the air and are 100 percent efficient. This is true, but no electric or sealed-combustion heating system removes humidity. Oxygen levels are not affected by any electric or vented-combustion heating source, he said.

“While the advertising claims made for these infrared heaters are mostly true, they make the system sound like a revolutionary advancement in home heating,” he said. “You can get similar benefits from a good-quality space heater for much less than $300 to $400. If they have the same wattage, a $40 heater pays back a lot quicker than a $400 heater. In addition, they are both putting out the same amount of heat.”