More microwave ovens have come to the market with additional features like steaming and grilling, but are they safe and convenient to use?
With this question in mind, the Consumer Council had collaborated with the Electrical and Mechanical Services Department (EMSD) in a joint study on different types of microwave ovens.
The samples included 3 small conventional microwave ovens (HK$399 to HK$550), 4 grill microwave ovens (HK$520 to HK$1,290) and 3 steam and grill microwave ovens (HK$1,668 to HK$3,780).
Out of the 10 models, 6 models were found to be in full compliance with the IEC safety standards, while the remaining 4 models were detected to have 1 or 2 safety deficiencies: 2 models with deficiencies in resistance to heat and fire, 3 models with deficiencies in marking and instructions. Based on these test results, EMSD considered that all test models are safe to use under normal operation.
The study also looked into the performance of the microwave ovens in terms of their energy efficiency, actual microwave power output and heating performance.
The energy efficiency of these ovens ranged from 47% to 61%, the higher the efficiency, the more cost-saving.
In terms of microwave power output, the output of the samples was found to be lower than their rated value when measured at Hong Kong's mains voltage 220V. The measured microwave power output of one model was found to be more than 20% short of its rated value.
As the rated voltage of some microwave ovens will lie in the range of 220V to 240V, the manufacturers might have measured the rated power output at the voltage of 230V or above, but most manufacturers did not indicate clearly the voltage at which measurement was taken.
To better reflect actual usage situation and provide more reliable information to customers, the Consumer Council called on the manufacturers to list their information of microwave power output with reference to Hong Kong's mains supply voltage.
For people who love to cook, whether the microwave oven cooks evenly and efficiently may be more important. While 2 models had better performance in terms of evenness of heating, 2 models had a lower score given the temperature difference of over 7°C recorded between two glasses of water after heating - one placed at the center of the turntable and another placed at the edge.
For those who have children at home, they might look for an oven with a child safety lock. Among the samples, 7 had incorporated a child safety lock, of which 5 would require de-activating the lock before the oven could be turned on and operated.
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