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Washing and Drying Performance of 10 Washer Dryers Varied Power and Water Consumption Could Differ by Up to 80%

  • 2023.01.16

In the compact living space of Hong Kong apartments, it is hard enough to fit in a washing machine itself, not to mention the humid weather and the extra space required to hang-dry laundry. As such, washer dryers with the dual functions of washing and drying clothing have become an increasingly popular solution. However, according to the Consumer Council’s test on the washing, drying and wash-and-dry combo functions of 10 washer dryer models on the market, the cleaning performance, water extraction performance, drying precision, energy and water consumption, as well as the cycle time were found to vary substantially. The performance of the same model also varied considerably when used for different textile materials, and when running different programmes. The 3 models with the best cleaning performance, which received 4.5 points each, as well as the 3 models with the best drying precision all came from different brands. On the other hand, the 2 models which received the highest rating for the energy-saving performance of their wash programme were amongst the worst-rated models in terms of the dry programme’s energy-saving performance. These divergent results were mainly related to the product design. Therefore, consumers should carefully consider their personal laundry habits, most frequently washed and dried garment types, and most valued product function, so as to make a smart purchasing decision for a washer dryer.

The 10 models included in the Council’s test were all front-loading types, which is the most common type of washer dryers available on the market, and ranged from $5,390 to $21,980 in retail price. The claimed maximum washing capacity of 9 models were 8kg, while that of the remaining model was 7kg. The claimed maximum drying capacity ranged between 4kg to 6kg, whereas the maximum water extraction spinning speed ranged from 1,200 to 1,600 revolutions per minute (rpm). Test items included the clothes-washing and drying performance, energy and water saving performance, washing and drying speed, etc., conducted in 6 different sessions to test the performance of the models when running different programmes, operating on clothing of 2 common textile materials (cotton and synthetic fibre) and different loads. Ultimately, the lowest and highest priced models both received the same overall rating of 4 points.

Cleaning and Water Extraction Performance Vastly Varied

It is a fundamental function of a washer dryer to clean garments properly and thoroughly. The models were tested for their cleaning performance of various stains, including blood, tea, wine, salad dressing, chocolate ice cream, lipstick, and ink, etc. The results revealed considerable variance in cleaning performance amongst models. For example, the cleaning ratios which reflected the cleaning performance varied by up to approximately 27% across all models in the “washing synthetic fibre clothing” session, while that for the “washing cotton clothing” session showed a variance as high as 20%. Even the same model performed inconsistently in different sessions, with an example being a model which had the highest cleaning ratios in 3 sessions, namely “washing cotton clothing”, “washing synthetic fibre clothing”, and “washing and drying synthetic fibre clothing”, but was not the best-performing model in the “washing and drying cotton clothing” session.

A better water extraction performance could consequently reduce the time required for hang-drying or machine-drying the clothing. The results indicated a vast variance in the water extraction performance amongst models, in particular during the “washing cotton clothing” session when comparing the weight of the same batch of clothing after water extraction and when fully dry, the remaining moisture content of clothing was found to range from 37% to 87%, a significant difference. The test also revealed that the 3 models with the claimed maximum water extraction spinning speeds of 1,400rpm and 1,200rpm respectively, in fact had a pre-set water extraction spinning speed of only 800rpm for the basic “cotton” and “synthetic fibre” wash programmes, which were the lowest amongst all models. As a result, these 3 models had a relatively poor water extraction performance in the test.

Almost 10% Difference Between Post-drying and Regular Dryness

Drying clothes for a prolonged period or at an excessively high temperature might cause deformation, shrinkage or even damage to the clothing. On the contrary, if the clothing had not been fully dried after the first cycle and the user chooses to restart the dry programme, the washer dryer would need to heat up the cooled-down clothing once again, as a result wasting energy and time. Besides, the clothing might start to emit odour if left in the drum for too long and would need to be rewashed, which also causes wastage. Therefore, the drying precision is crucial. The results showed considerable variance in the drying precision amongst models. Taking the test session “drying cotton clothing” for instance, for 1 model, the overall dryness of the clothing immediately after drying was considerably close to that when the clothing was in a dry state, with a mere difference of 0.1%. Another model, however, had a difference of 9.4%, with many clothes not fully dry. For the “washing and drying cotton clothing” session, the drying precision ranged from 0.8% to 8.8%.

Nevertheless, even the same model performed differently when used for drying different materials. The model with the highest drying precision in the “drying cotton clothing” session had the worst performance in the “drying synthetic fibre clothing” and “washing and drying synthetic fibre clothing” sessions as some of the garments were overly dry after the process.

Energy and Water Consumption Could Differ by Over 80%

With energy prices consistently on the rise recently, power and water consumption should also be key deciding factors when purchasing a washer dryer, apart from its cleaning and drying performances. The results showed a huge difference in energy consumption amongst models, with a maximum difference of approximately 79% in energy consumption for washing per kg clothing in the “washing synthetic fibre clothing” session for instance. The energy-saving levels of the same model could also drastically vary for different test sessions. The best-performing model with the lowest energy consumption per kg clothing in the “washing cotton clothing” session conversely had the highest energy consumption per kg clothing amongst all models in 4 other test sessions which included drying, and washing and drying.

Besides the wash programme, the dry programme also consumes water, mainly for cooling down the moisture formed in the washer dryer and condensing it into water droplets, which would then be collected and drained from the machine through the pipes. However, the water consumption of the dry programme was also found with great difference across the tested models. In the “drying cotton clothing” and “drying synthetic fibre clothing” sessions, the maximum difference in water consumption for drying each kg clothing was around 83% and 86% respectively. The same model had the highest water consumption in both the aforementioned sessions, yet this model had the most outstanding water-saving performance in the “washing cotton clothing” session, once again reflecting that the same model could have varying performance when operating under different wash and dry programmes, and when used for treating different textiles. 

Wash and Dry Programme Could Take Over 7 Hours to Complete

Consumers with a busy lifestyle would naturally desire a faster washing and drying speed. 3 of the tested models could complete the wash programme within 2 hours, while 1 model required over 3 hours. In terms of drying, 2 models were able to complete the dry programme within 3 hours, whereas 2 models took over 5 hours. For the wash and dry programme, 1 model could complete it within 4 hours, yet 1 model required over 7 hours to complete the entire programme. Consumers should bear in mind that the length of the wash cycle should not be the sole factor to be considered when choosing a washer dryer. The test recorded the time required by each model for the washing phase (excluding rinsing and water extraction). Generally speaking, the longer the washing phase, the cleaner the clothing. Besides, although many washer dryers feature “quick wash” and “quick wash and dry” programmes, they are usually only suitable for small amounts of laundry (such as under 2kg) and not severely soiled clothing.

A washer dryer could cost several thousand to even tens of thousands of dollars, yet the different models each had their own strengths and weaknesses in different test sessions. The model with the most outstanding cleaning performance did not perform the best in the drying precision test; the model with the most power-saving wash programme contrarily received the lowest rating in power-saving level for the dry programme. Consumers should select a model that matches their personal garment care habits, such as whether they have more cotton or synthetic fibre clothing. Appropriate use and good maintenance could extend the lifespan of the machine, supporting the principle of sustainable consumption. Consumers could refer to the following tips:

  • Washer dryers should not be placed outdoors or in humid environments, such as in the bathroom, to prevent water from seeping into the appliance;
  • The claimed maximum drying capacity of washer dryers is lower than the claimed maximum washing capacity. When washing a relatively large load, some of the laundry should be removed after the wash programme before activating the dry programme, to prevent exceeding the drying capacity which would affect the drying results;
  • Sort laundry by fabric type or dirtiness, then select the appropriate programme according to the user manual. This practice could save water and electricity as well as ensure better garment care;
  • Excessive amounts of laundry detergent might not enhance the cleaning performance, instead not only wasting money, but possibly accumulating in the washer dryer, or producing large amounts of suds that could impact the operation of the washer dryer;
  • Never dry latex foam rubber, or garments containing rubber or wax in a washer dryer, as the materials could melt under high heat or even pose fire hazards;
  • Some washer dryers are equipped with a “drum cleaning” programme. Consumers are recommended to run this programme at least once a month according to the user manual. For models without a “drum cleaning” programme, consumers could run a wash programme with an empty load at high water temperature setting to clean the drum regularly.

 

Download the article (Chinese only):  https://ccchoice.org/555washerdryers

 

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