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Energy Saving Tips on Use of Electric Kettles - CHOICE # 444

  • 2013.10.15

For the energy-saving conscious, kettles with a keep-warm function are clearly not their preferred choice. It is because these kettles could run up the electricity bill considerably - by as high as some $700 a year - just to keep the water warm.

This was borne out in a Consumer Council test on 15 samples of electric kettles, 6 of which came with a warmth keeping feature which keeps the water warm after it has been boiled so hot water is kept readily available.

In the test, the energy consumption of the 6 samples was measured for 24 hours for keeping full capacity of water at the highest keep-warm temperature.

One sample only kept warm for 30 minutes and the appliance was automatically cut off. 2 others designed with sealed-lid heat insulation were found to consume about 0.5 kWh per day for warmth keeping.

However, 2 samples of normal kettle design without heat insulation saw their energy consumption rise significantly by 1.2 kWh and 1.7 kWh respectively, costing in the case of the latter an extra $683 a year in electricity.

It will work out more economical to simply boil only the amount of water you need each time. But if you do have need of a keep-warm function, use it for only a short time then switch it off to save energy.

For boiling performance - the time taken to boil one litre of water - generally the more powerful the kettle the faster it boils. The test showed the fastest samples (with rated power of 2,500 W-3,000 W) took only 2 minutes 40 seconds while the least powerful performer (393 W-430 W) took a slow 16.5 minutes.

Consumers are advised to pay heed to a kettle's minimum water level. 2 samples needed only a minimum level of 250 ml of water to boil, unlike most others of at least 500 ml, which saves time and energy.

But users are reminded not to fill in water below the minimum water level to avoid overheating, or above the maximum water level.

In the test to measure the boiling temperatures of the kettles, most samples were found to bring water to a boil at over 99℃ and only 2 samples at 98℃. Although just stop short of 100℃, the boiled water is considered safe to drink.

4 kettles were designed with variable heating temperatures for making hot drinks such as instant coffee or green tea. While it saves time and energy, the temperature could get as low as 50℃, users are therefore recommended to use distilled or otherwise treated water to minimize the risk of micro-organism.

On safety, 3 samples were found with insufficient electrical insulation distance - the test finger being accessible to the basic insulated wire, or the distance across the live parts of opposite polarities being slightly less than the limit of the standard.

Further, the plastic materials of 3 samples were found to be of inadequate resistance to heat and fire. Other findings included insufficient warning statement in the instruction and slight overheating in one other sample.

In the sensory evaluation of drinking water in electric kettles, all models were put to a simulated test using the kettles with distilled water for two weeks and the results proved all samples were free of unpleasant taste or odour.

Consumers are advised not to share the same socket with other high-consumption electrical appliances. Do not wet the electrical connecters (the kettle base) and wipe off any water before switching on the appliance. After use, place the kettle against the wall to avoid toppling and store the cord in the base to avoid pulling by children.

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