Air conditioners that operate with the highest of energy efficiency and the lowest of noise level will probably be a best-buy recommendation to many would-be purchasers.
Help is at hand in a Consumer Council test report on 15 models of window-type room air conditioners with claimed cooling capacity of 3.40 kW to 3.85 kW commonly referred to as "1.5 horse-power" units.
Amongst the test samples were 2 models which fit the bill both scoring the highest energy efficiency and the lowest indoor noise level during operation.
Together with 4 other samples, they were the top performers in the test each scoring overall 4.5 points on a 5-point scale.
The overall rating was based on: energy efficiency (40%), noise level (20%), safety (20%), ease of use (10%), cooling capacity (accuracy in its claimed value) (5%), and enclosure sweat and condensate disposal (5%).
In fact, the great majority of the samples were deemed to have good energy efficiency. An air conditioner of low energy efficiency would run up more energy resulting in a higher electricity bill to the users.
According to the test, all samples but one would have qualified for Grade 1 rating under the Energy Efficiency Labelling Scheme of the Electrical and Mechanical Services Department.
In terms of annual running cost of electricity, the samples varied from an estimate of $1,952 to $2,188, a difference of about 11% or savings of $236 in one year.
The test also showed that for cooling capacity, most of the samples were found to fall slightly below their own claim, with the biggest discrepancy at about 6%.
Though all samples passed the condensate disposal test, under the extremely humid ambient condition in summer, air conditioners may still produce dripping on the outside as the large amount of condensate water may not evaporate fast enough. Consumers are advised to install a drain hose if dripping occurs.
A series of safety tests was performed with reference to IEC60335-2-40. Only one sample had problem with the earth continuity test: the electrical resistance between the earthing terminal and external metal enclosure exceeds the maximum allowed limit in the standard. However, it is considered safe to use under normal operation.
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