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First-ever Test on the Cooling and Heating Performance of “1 Horsepower” Inverter Split-type Reverse Cycle Air Conditioners Energy Efficiency Found to Vary by Over 30% Check Out the Warranty Period Carefully

  • 2022.04.13

Amid the pandemic, many people have spent longer hours working or attending remote classes at home due to social distancing measures. Besides, with summer just around the corner, a fast-cooling and energy-saving air conditioner is essential for keeping the whole family cool at home. The Consumer Council tested 14 models of “1 horsepower” (HP) inverter split-type air conditioners, covering the heating performance of 7 reverse cycle air conditioner (RCAC) models for the first time. 1 horsepower air conditioners are the most commonly used type in the compact living space in Hong Kong. The results revealed that despite all models achieving Energy Efficiency Grade 1 based on the appliance’s Cooling Seasonal Performance Factor (CSPF) or Heating Seasonal Performance Factor (HSPF), the CSPF and HSPF values amongst the models varied by as much as around 30% and 35% respectively, representing a vast discrepancy in energy efficiency and energy-saving performance. Consumers looking to cut back on their electricity bills should choose carefully before purchasing.

According to the test results, 5 out of the 7 RCACs were rated 4.5 points overall whereas their price varied by 2.5 times. While the highest priced model had an outstanding overall performance, its cooling and heating energy efficiency were slightly inferior than 2 cheaper models respectively, once again demonstrating that quality choices are available at different price ranges.

The 14 models of inverter split-type air conditioners, priced from $4,680 to $16,400, included 7 RCACs which provided both cooling and heating functions, and 7 cooling-only air conditioners. All models were rated Energy Efficiency Grade 1 under the Mandatory Energy Efficiency Labelling Scheme (MEELS), including 6 models using the more eco-friendly R32 refrigerant. The test was conducted with reference to the international standards ISO 5151, ISO 16358-1, ISO 16358-2 and IEC 60335-2-40, with test items including the cooling capacity, heating capacity, energy efficiency, noise level, air flow rate, dehumidifying performance, safety level and ease of use.

The cooling capacity of air conditioners is crucial as the higher the value, the faster it cools. The test revealed outstanding cooling performance across all models, with the measured cooling capacity ranging from 2.55kW to 2.88kW, all higher than claimed, amongst which 1 cooling-only model even achieved 10.8% higher than its claimed value of 2.60kW. On the other hand, the heating performance of the 7 RCAC models with heating function could vary by around 19% (2.67kW to 3.30kW), of which the measured heating capacity of 4 models were higher than claimed (1.0% to 6.9% variance), while that for the remaining 3 models were lower than claimed (0.6% to 2.9% variance). Although the variance fell within the acceptable tolerance range (10%) under the “Code of Practice on Energy Labelling of Products” and common international practice, consumers generally expect the actual heating capacity of products to meet their claims as with the cooling capacity. As such, the products still see room for improvement.

While enjoying air conditioning, consumers also hope to purchase products which can cut back on electricity costs. A higher CSPF value represents higher energy efficiency for cooling and better energy-saving performance. Despite the fact that all models met the Energy Efficiency Grade 1 standard under the current MEELS, the models’ CSPF values ranged from 5.28 to 7.72, equivalent to a considerable variance of up to 31.6%, meaning that the model with the highest CSPF could save over 30% more in energy versus the model with the lowest CSPF. In particular, the RCAC models had a variance of 30.1% between the models with the highest (7.72) and lowest (5.40) CSPF, while the cooling-only category showed a greater variance (11.3%) amongst the models with non-compact outdoor units.

Besides, the 2 tested RCAC models with the highest CSPF (7.72 and 7.38) had a higher cooling energy efficiency than the inverter air conditioners or RCACs previously tested by the Council, reflecting that it is technologically feasible for manufacturers to offer more energy-efficient products for consumers. The results also revealed that despite all models achieving Energy Efficiency Grade 1, the energy efficiency still varied by over 30% amongst models. On the other hand, as of mid-March 2022, up to 72% of the split-type air conditioner models in the “Record of Listed Models” under MEELS were rated as Energy Efficiency Grade 1 for cooling performance based on the current grading standard. Apart from urging manufacturers to proactively introduce more energy-efficient products, the Council also recommends the Electrical and Mechanical Services Department (EMSD) to consider further upgrading the energy efficiency grading standard for air conditioners. Not only would this promote environmental protection and sustainable consumption, it could also help users save on electricity bills.

The heating energy efficiency for RCACs is reflected by the HSPF value, with a higher value representing higher heating energy efficiency and better energy-saving performance. The HSPF values of the 7 RCAC models ranged from 4.07 to 6.13, a 33.6% variance, meaning that the model with the highest HSPF value could save 33.6% more energy for heating versus the lowest one.

The Council recommends consumers to select air conditioners with higher CSPF and HSPF values, as they are more eco-friendly and cost-saving. Based on the tariff of $1.3 per unit of electricity and the scenario where the air conditioner operates with the cooling function for 12 hours per day for 180 days a year, the estimated annual electricity tariff for cooling ranged from $401 to $581 amongst the models, a difference of $180. In terms of heating, if the heating function runs for 25 days a year for 12 hours per day, the estimated annual electricity tariff of the 7 RCACs for heating would range from $35 to $53, an $18 difference.

The actual cooling or heating load could be impacted by a number of factors, resulting in an increased electricity tariff. Take cooling for instance, the humidity, a larger space, windows facing direct sunlight, draughty doors and windows, having the ventilation fan on, multiple electrical appliances operating at the same time, or a greater number of people in the room, etc., could cause the electricity costs to surge. Besides, if the annual total operation time of the air conditioner is longer, or the user tends to adjust the cooling function to a lower temperature or the heating function to a higher temperature, the actual bill would be much higher than the Council’s estimate.

Consumers should also pay heed to the warranty period and the annual warranty fee, as this could reduce expenses in case of future repairs as well as extend the lifespan of the appliance. According to the survey, only 3 models offered a 2-year warranty period for the full machine, while the remaining 11 models only provided a full machine warranty period of 1 year. In terms of the warranty for the air conditioning compressor, only 1 model offered a 10-year warranty, while over half (9 models) provided a 5-year warranty, and the remaining 4 only offered warranty for 1 or 3 year(s). After the initial warranty period, only 12 models provided annual warranty renewal at fees ranging from $620 to $1,500, a difference of 1.4 times. The model with the highest annual warranty renewal fee only had a 1-year full machine warranty for the brand new appliance. Furthermore, some agents have set conditions for warranty renewal, for example renewal would not be provided for customers in remote areas such as outlying islands, Tung Chung, etc., or that on-site inspection was required before approving the renewal application.

Within the warranty period, the agents of all models provided free on-site inspection service in urban areas, while a surcharge might be required for customers in remote areas. After the warranty period, the on-site inspection fees in urban areas ranged from $350 to $950, a difference of over 1.7 times; the fees for remote areas were even higher, ranging from $570 to $1,560. Even within the initial warranty period for new appliances, some of the service charges also saw huge disparities. Taking for example the cleaning service of both indoor and outdoor units in an urban area, the charge ranged from $1,000 to $3,000, marking a 2-time difference. The cost of the most expensive cleaning service ($3,000) charged by the agent for 1 air conditioner was close to almost half (48%) of the original price ($6,280) of the appliance.

When installing split-type air conditioners, consumers should also be mindful of the extra expenses for the scaffolding. Construction of scaffolding might be required for repairing outdoor units of air conditioners, the costs of which would generally be borne by the customer and were not included in the basic maintenance or warranty plan. Some agents or manufacturers provide scaffolding supporting plans at an additional cost, generally offering reimbursement of the scaffolding fee up to a specified amount for participating customers. Consumers should enquire with the agent or manufacturer about the details before deciding on whether to participate or not. Amongst the tested models, the agents or manufacturers of 3 models provided this type of plan.

Consumers can refer to the following tips when using air conditioners:

  • When the air conditioning is on, draw the curtains and close the doors and windows to maintain the interior temperature;
  • Use a fan alongside the air conditioner to direct the cool current towards yourself, and set to a higher temperature to save power;
  • During summer, it is recommended to clean the dust filter, air inlet and outlet once every 2 weeks to keep the air conditioner at its best performance; 
  • Select a higher wind speed setting if possible, to achieve the best cooling and energy-saving performance;
  • Using an RCAC in the winter is far more energy efficient than using a heater or fan heater. Consumers can also dress more warmly at home and have the RCAC set to around 16°C to 18°C, which should be reasonably comfortable.


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