Cooling Energy Efficiency Could Vary by up to 33% Among Grade 1 “1.5 Horsepower” Inverter Split‑type Air Conditioners Advocating Strengthening of Grading Standards To Facilitate Smarter Choices

Hong Kong’s hot and humid summers have made air conditioners an essential household appliance. Beyond cooling performance, energy efficiency plays a major role in determining electricity costs. The Consumer Council, in collaboration with the Electrical and Mechanical Services Department (EMSD), tested 13 models of “1.5 horsepower (HP)” inverter split‑type air conditioners available on the market. These included 7 reverse cycle air conditioner (RCAC) models and 6 cooling‑only models. Although all models were labelled Grade 1 for energy efficiency, the test results showed substantial differences in performance. Cooling energy efficiency varied by as much as 33% among the models, while heating energy efficiency varied by up to 14% across RCAC models. The tests also found that the measured cooling capacity or heating capacity of 3 models was 1% to 3% lower than their claimed values, though the discrepancies were still within the 10% tolerance range permitted under the Mandatory Energy Efficiency Labelling Scheme (MEELS) and common international practice.

The Council opines that the current grading standards for air conditioners have room for strengthening to better reflect the variance between the energy efficiency among products, so as to help consumers make more informed choices. The test results also indicated that some products still have room for technical improvement. The Council encourages relevant manufacturers to step up research and development efforts, and introduce more energy-efficient products to promote sustainable consumption.

The test covered 13 models of “1.5 HP” inverter split-type air conditioners, including 7 RCAC models priced from $8,380 to $19,610, and 6 cooling-only models priced between $4,890 and $7,880. Some models were sold with basic installation included. The claimed cooling capacity of the 13 models ranged from 3.300kW to 3.550kW, while the claimed heating capacity of the 7 RCAC models, ranged from 3.500kW to 4.300kW.

The tests were commissioned separately by the Council and the EMSD and carried out by independent laboratories. The EMSD tested the cooling capacity, cooling energy efficiency, heating capacity and heating energy efficiency^[1], while the Council assessed safety, noise level and ease of use. All models passed the safety tests.

Cooling Capacity of 2 Models and Heating Capacity of 1 Model Fell Slightly Short of Claims

Cooling performance is usually the main consideration for consumers when choosing an air conditioner. The cooling capacity of the 13 models measured at maximum load ranged from 3.310kW to 3.738kW. For 11 models, the measured values were 0.3% to 6.8% higher than their claimed capacities, indicating good conformity. The remaining 2 models recorded cooling capacities 1.0% and 3.0% below their claimed values respectively, performing less satisfactorily. Although all aforementioned discrepancies fell within the 10% acceptable tolerance under the MEELS and common international practice, the Council reminds the concerned manufacturers to tighten quality control to ensure the product’s actual performance meets consumers’ reasonable expectations.

When assessed on basic functions only (i.e. excluding the heating function of RCACs), 7 models performed better, each receiving 4.5 points overall. These included 6 RCAC models and 1 cooling‑only model priced from $7,880 to $19,610, suggesting that well‑performing options are available across different price ranges.

Some consumers may consider purchasing RCACs due to usage needs. The heating capacity of the 7 RCAC models measured under maximum load ranged from 3.528kW to 4.469kW, of which 6 models recorded heating capacities 0.8% to 3.9% higher than their claimed values, while 1 model fell 1.4% below its claim, though still within the permitted 10% tolerance range under MEELS and common international practice. While differences in cooling capacity among these 7 RCAC models were relatively small, with less than a 4% gap between the highest and lowest results, heating capacity varied more significantly, with a maximum difference of about 27%. Consumers may therefore choose models according to their specific needs.

All Rated Grade 1 yet Energy‑saving Performance Varied by as Much as 33%

The Cooling Seasonal Performance Factor (CSPF) indicates the cooling energy efficiency of an air conditioner, with higher values representing greater energy efficiency. The CSPF values of the 13 models ranged from 5.057 to 7.510. Despite all models being rated Grade 1, the differences in cooling energy efficiency were significant. Based on CSPF values, the most energy‑efficient model could save up to 33% more energy annually than the least efficient one^[2]. Compared with a similar test conducted in 2021, where the average CSPF of 14 models was 5.582, the average CSPF in this test rose to 6.266. This suggests that, on average, the models tested this time were about 11% more energy‑efficient in cooling than those tested in 2021.

For heating performance, the Heating Seasonal Performance Factor (HSPF) values of the 7 RCAC models ranged from 5.002 to 5.796. All were also rated Grade 1 for heating energy efficiency. However, based on HSPF values, the most efficient model could save up to 14% more electricity annually than the least efficient one^[3].

With reference to the international standard method of calculating electricity consumption, the outdoor temperature and time distribution data adopted by the MEELS, and the current test results, based on the cost of $1.6 per kWh, the estimated annual electricity cost for cooling is $679 to $1,022 assuming operation for 12 hours per day for 180 days a year; and that for heating (for 7 RCAC models only) is about $54 to $69 per year assuming operation of 12 hours per day for 25 days a year. Actual electricity cost will vary depending on various factors including the length of use, maintenance condition and electricity tariffs.

The current energy efficiency grading standards for cooling performance of split‑type air conditioners have been in place since 2014. The test results showed that even among Grade 1 models, the cooling energy efficiency can differ substantially. The Council opines that there is room to further strengthen the grading standards of air conditioners to better reflect actual energy efficiency differences among products, so as to help consumers make informed choices and encourage suppliers to introduce more energy‑efficient products, thereby promoting sustainable consumption.

2 Models Offered No Extended Warranty

Longest Full Machine Warranty of 3 Years

Apart from performance, after‑sales support is another key concern for consumers. The full machine warranty period for new machines ranged from 1 year to 3 years, of which almost half of the models provided only a 1‑year warranty, while just 1 model offered the longest 3‑year full machine warranty. For compressors, which are generally more durable, most models offered warranties of 3 years or 5 years, with only 1 model providing a 10‑year warranty.

As for warranty renewal, apart from 2 models which did not offer such service, the annual extended warranty fees for the remaining models ranged from $620 to $1,650. During the initial warranty period, labour and spare parts charges were generally waived for damages not caused by human factors. However, the arrangements during extended warranty periods varied among suppliers, with some continuing to waive parts charges, while others only offered discounts of different magnitudes. Certain extended warranty plans also imposed limits on machine age or excluded remote areas. Consumers are advised to review the terms carefully before taking out extended coverage.

Split‑type air conditioners typically cost thousands of dollars or more. The Council urges suppliers to offer longer warranty periods and more affordable warranty renewal and maintenance fees, so as to encourage consumers to repair appliances where possible and extend their service life.

When purchasing, installing and using air conditioners, consumers can refer to the following safety and energy-saving tips:

• Avoid purchasing air conditioners that do not comply with local specifications from online stores. If fixed wiring is required, a registered electrical contractor must be engaged to carry out the electrical work;
• Choose models with a Grade 1 energy label and refer to the “annual energy consumption” figures shown on the labels to compare the energy-saving performance of different models;
• Electric fans consume far less electricity than air conditioners. By using a fan to direct the cool air towards the user, the air conditioner can be set at a higher temperature to reduce electricity consumption;
• Do not block air inlets or outlets of air conditioners during operation. After switching off the unit, avoid restarting it immediately. Use the timer function where available to avoid prolonged operation or forgetting to switch off. Also remember to switch off the unit before leaving home;
• Clean dust filters, air inlets and outlets at least once every 2 weeks during summer, and arrange regular inspection and maintenance by experienced technicians. Deep cleaning of the air conditioner involves disassembling and reassembling parts, so it is recommended to be handled by air conditioner suppliers or professional cleaning companies;
• Refrigerant is sealed within the system and generally does not require replacement or refilling unless leakage occurs or when major repairs, such as compressor replacement, are needed. Such work should be carried out by experienced technicians.