Are lowly-priced inexpensive electric heaters a sensible choice for household use? The overriding concern is with their safety.
To assess their safety, the Consumer Council has put to test 12 models of electric heaters, ranging in price from just $99 to $880.
The results, in accordance with the latest IEC international safety standard, are as reassuring as they are worrying to the consumers.
Of the 12 samples, five stood out above the others with a top 5-point overall score in safety. The score was based on: flammability of the material used (35%), construction (30%), stability (20%), temperature rise (10%), and markings and instructions (5%).
Among the top performers were three models of fan heaters with two of them at the lowest end of the price range - at $99 each.
The two other models with top overall score were an oil-filled radiator at $399 and a radiant heater at $199.
It would appear that, on the basis of the test, fan heaters are among low-cost electric heaters a relatively more reliable choice in safety.
On the other hand, the results showed that six of the 12 models were considered to have comparatively less resistance to fire.
In the flammability test (using a 750℃ hot glow-wire), it was found that some plastic insulating materials of these samples passed the test with flame produced that self-extinguished within 30 seconds, but lasted for more than 2 seconds.
It was therefore necessary to follow up with a subsequent test (using a needle-flame) on the other plastic materials in close proximity.
All six samples were found to contain materials that could not pass the needle-flame tests, liable to pose a comparatively higher risk of fire in the event a flame is started inside the heater.
This potential hazard was found in models of the various types of electric heaters included in the test.
Another safety issue concerns the stability of the heaters. Two oil-filled radiators were found to be unstable and toppled over on a 15°inclined plane. Such accident might injure the feet of people nearby and toddlers in particular. Consumers are advised to place an operating electric heater properly on the floor and away from children to avoid accidental toppling.
The oil-filled radiator samples were also tested for oil spillage. One sample was found to leak at about 1.6 times of the abnormal pressure built up internally of the oil container, falling short of the standard which requires that the heater shall withstand twice the abnormal pressure.
A spillage test was also conducted on a radiant heater with a water container for steam generation (similar to a humidifier). It failed the subsequent electric strength test as the insulation strength between the water drain hole and the live parts was found to be reduced. Users are recommended to unplug the heater and dry all dripping water before use to ensure safety.
Some minor deficiencies were found in construction such as inappropriate earthing connection, the length of internal earthing lead shorter than the neutral lead at the power supply cord anchorage, etc.
Other safety tips for consumers of electric heaters:
- Do not operate heaters near combustible materials such as bed sheets, curtains, clothes, carpets or sofa, to prevent fire risks.
- Unless specially designed, heaters shall never be used to dry clothes.
- Heaters are usually power-consuming; do not share a same power outlet with other appliances.
- Oil-filled radiators are heavy and hot, watch out for young children being hit by an accidental falling heater or scorched by the invisibly hot surface of the oil container.
- Users might feel the air becoming dry when heater is in use. Unless the heater has steam or moisture generating feature, users could consider using humidifier.
- To save electricity, turn off the heater when no one is in the room.
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