85% of Two Horsepower Window-type Air Conditioners Fail Own Claims in Test on Cooling Capacity and Energy Label of 1 Model Unsubstantiated

15 May 2019
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With summer fast approaching, an air conditioner that cools fast and saves energy is an important appliance at home.  The Consumer Council conducted a test on 14 models of the “2 horsepower” window-type room air conditioners, including 2 new inverter type air conditioners.  However, 12 models failed to live up to their claimed cooling capacity, falling slightly short of the actual measured cooling by 0.9% to 3.2%.  Though all models displayed Energy Label Grade 1, they varied in energy savings up to an estimated maximum difference of $659 annually, and 1 model met only the Grade 2 energy efficiency rating.  Furthermore, the Council found upon expiry of the product warranty period, the annual renewal warranty for some models costed more than double that of others.  The Council urges consumers to check the variations in the arrangements and fee charged by agents when purchasing an air conditioner, particularly for after-sales service, such as maintenance inspection and cleaning services. 

Consumers often take a passive approach to choosing after-sales service.  The high cost of repairs and maintenance may result in consumers replacing air conditioners that could in fact be repaired.  Manufacturers and agents are urged to offer a longer warranty period, lower annual renewal fee and maintenance charges to encourage consumers to have faulty air conditioners repaired instead of replacing them, in order to promote sustainable consumption.

Included in the test were 14 models of window-type air conditioners with claimed cooling capacity of 5.0 to 5.3 kilowatts (kW).  12 were the fixed-capacity type, priced from $5,399 to $8,780, and 2 were the inverter type (or variable-capacity type), priced at $10,980 and $12,500.  4 models included installation charges in the price, while the rest require a surcharge of $400 to $600 for installation.  Following the international standards commonly adopted by manufacturers, ISO 5151, ISO 16358-1 and IEC 60335-2-40, the test focused on cooling capacity, energy efficiency, quietness, air flow, dehumidifying performance, safety and ease of use.  The results showed that the 2 variable-capacity inverter models achieved better overall performance ratings, with 5 and 4.5 points, while the 12 fixed-capacity models were rated at 3 to 4 points.

The cooling capacity of air conditioners is clearly the most important factor – the higher the cooling capacity, the faster the cooling.  In the test, the cooling capacity of the 14 models ranged from 4.94 to 5.25 kW.  12 of the models were lower than the claimed value by 0.9% to 3.2%.  Although the discrepancy was within the acceptable 10% limit of the Code of Practice on Energy Labelling of Products and international practices, the Council stressed that it is a basic right of consumers to obtain accurate information, and that since the cooling capacity of air conditioners is such vital product information, manufacturers should do their utmost to ensure its accuracy.

All the models in the test displayed Energy Label Grade 1, but according to the Mandatory Energy Efficiency Labelling Scheme grading standards, only models with a Cooling Seasonal Performance Factor (CSPF) higher than 3 can be classified Grade 1.  The CSPF value of 1 model was found to be only 2.91, which meets only the Grade 2 rating.  Though the discrepancy was within the 8% acceptable limit in international practice, the Mechanical and Electrical Services Department has demanded that the supplier improve the product energy efficiency performance and quality control.  The CSPF of the rest of the fixed-capacity models was 3.0 to 3.1, compared to 4.12 to 4.17 for the inverter models.  The difference between the 2 groups of air conditioners was a considerable 39%.

Energy efficiency has a direct impact on consumer electricity bills.  At a unit cost of $1.2, if the air conditioner is run 180 days a year, 12 hours a day, the annual electricity bill for these models would vary from $1,311 to $1,970, a difference of $659.  Other than actual cooling capacity, consumers are reminded that other factors, such as a humid environment, relatively big room size, wind seepage through windows and doors, the indoor environment, and the number of people in the room, may also increase the cooling capacity load and affect the energy efficiency of the air conditioner.

As variable-capacity inverter air conditioners automatically adjust the operation speed according to the actual environment, the test found the Energy Efficiency Ratio (EER) of the 2 inverter models under full load to be 2.46 and 2.42, or an average of 2.44, which is 18% lower than the average for fixed-capacity models.  But when tested under half load (50% cooling capacity), their EER jumped up to 62% higher than the test under full load.  To gain the full benefits of inverter models in terms of high performance and energy savings, when turning on the air conditioner, the temperature should be adjusted down by phases until it reaches the target temperature to avoid prolonged operation of the machine under full load.

Consumers should be equally concerned about after-sales service, including the product warranty period, maintenance and repairs.  The Council found that most models were covered by full warranty for 3 years or more, but the warranty period of 3 models was only 2 years.  The warranty period for the air conditioner compressor for all models was 5 years or more, with 1 model offering a permanent warranty.  But upon expiry of the warranty, the annual renewal maintenance fee was between $400 and $870, a difference of more than double.

During the warranty period, agents provide users of all models with free home inspection service in the urban areas, but a surcharge is imposed for users living in remote areas.  After the warranty expires, the home inspection fee in the urban area is $300 to $540, a difference of 80%.  But even under a maintenance agreement, the arrangements and charges for some services vary.  In the case of air conditioner cleaning, for instance, the agents of 2 models offer no such service, and the agent for 1 model does not cover service in remote areas.  Even when the service is provided in urban areas, the fees vary by double from $500 to $1,000. 

In summer, many families keep their air conditioners on for long periods, so the following tips are provided to help in choosing an air conditioner:

- The height and width of the variable-capacity and fixed-capacity air conditioners are very similar, but because of the more complex design of the machine parts for the inverter type, its body is generally deeper and heavier.  Check whether the installation position and size is suitable for what types;

- When using a variable-capacity air conditioner, set the target temperature by phases.  After turning on the air conditioner, first set the thermostat at a slightly higher temperature than you want, and then adjust it downwards every 15 minutes until it meets the desired temperature.  This helps reduce the time the machine has to operate at full load and saves energy;

- Some retailers include the basic installation fee in the marked price, but check before buying to be sure.  Even if there are pre-designated positions for air conditioners, the installation must be secured on cement, and the metal frame support must be connected with equipotential bonding to minimise the risk of accidental electric shock;

- If there is no preset position for the air conditioner, and it must be installed on the window frame, ensure that the window frame and supporting structure are strong and secure enough to bear the weight;

- New residential buildings with glass screen walls may not permit the installation of window-type air conditioners; they may permit only split-type air conditioners at pre-designated positions.  This may result in exorbitant installation fees, as it requires an advance appointment and rental of the building gondola to carry out the work.

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