In recent years, the fresh air industry in mainland China has developed rapidly. With the increase in environmental awareness, consumers have a deeper understanding of the fresh air system. In the past, fresh air systems were mainly sold to factories, hotels, schools, and office buildings through engineering channels. However, in recent years, with the expansion of the retail market and the impact of the epidemic, more and more consumers have chosen to purchase and install fresh air systems independently. The fresh air system is composed of fans, purification equipment, air ducts and related components, and its function is to send the purified and filtered fresh air into the room, and at the same time discharge the indoor air out of the outdoors to achieve good ventilation effect.
According to the different air supply modes, the new fan can be divided into one-way flow, two-way flow, one-way flow + internal circulation, two-way flow + internal circulation and other types; according to the energy exchange mode, it can be divided into heat exchange (heat recovery), electric heating, combined and other different types; according to the difference in installation methods, it can be divided into ceiling type, wall-mounted, floor-mounted type and other forms. In order to help consumers understand the quality of new fans on the market and guide consumers to purchase scientifically and correctly, the Guangdong Provincial Consumer Council and the Foshan Municipal Consumer Committee jointly carried out this comparative test of new fans.
Compare trial details
First, the sample situation
1. A total of 15 samples were purchased by the staff as ordinary consumers from e-commerce platforms (Jingdong, Tmall, Suning Tesco) and offline agency channels, with unit prices ranging from 435.99 yuan to 15,998.98 yuan.
2. Among the 15 samples, there are 9 unidirectional flow fresh fans and 6 bidirectional flow fresh fans with heat recovery function.
3. The brands involved in the sample are: Midea, Haier, Panasonic, Yuanda, Mijia, Guomai, Fudan Shenhua, Dream Maker, Air Fort, Philips, Green Island Wind, Gree, Bailang, MATE.
2. Test indicators, standards and methods
The working principle of the one-way flow fresh air fan is to introduce the outdoor air into the room after filtration, so that the indoor air pressure is slightly higher than the outdoor, and squeeze out the dirty air through the gaps in the doors and windows to achieve forced ventilation and promote indoor air flow. According to GB/T 34012-2017 "Air Purification Device for Ventilation System", this comparative test tested the air volume, noise, PM2.5 purification (filtration) efficiency and other indicators of 9 unidirectional flow fresh air fan samples.
The two-way flow fresh air fan introduces fresh air through the air supply outlet, and then discharges the indoor dirty air to the outside through the air outlet, so that indoor and outdoor ventilation can be completed without opening the window. When the temperature difference between winter and summer is large, the heat recovery function of the bidirectional flow fresh air fan can neutralize the temperature of the hot and cold air inside and outside the room through heat exchange, so as to reduce the temperature difference between the fresh air and the indoor air. According to GB/T 34012-2017 "Air Purification Device for Ventilation System" and GB/T 21087-2020 "Heat Recovery Fresh Air Unit", this comparative test tested the air volume, noise, PM2.5 filtration efficiency of fresh air and net fresh air rate of fresh air supply, cooling capacity, and full heat exchange efficiency of heat recovery of 6 bidirectional flow fresh air fans with heat recovery function.
3. Compare the test results
(1) Main conclusions
1. Air volume is the core performance index of the new fan, among the 15 samples, 13 models have complete air volume ratings, and the tested air volume meets the national standard.
The measured noise of the 2.15 samples is between 31-51 decibels, and the sound is between the humming sound of a refrigerator and the sound of normal conversation.
The PM2.5 purification (filtration) efficiency of 3.15 samples reached more than 90%.
4. Among the 6 samples of fresh air fans with heat recovery function, 5 samples have a net fresh air supply rate of more than 95%, and the other 1 sample has a net fresh air supply rate of less than 90%.
Among the 5.6 samples of fresh fans with heat recovery function, 5 models of cooling capacity and heat recovery full heat exchange efficiency met the requirements of the national standard, and the measured value of the total heat exchange efficiency of 1 sample was 42.70%, which was less than 90% of the rated value.
Among the 6.15 samples, 11 samples were incomplete, including PM2.5 purification efficiency, air volume, external residual pressure, noise, and net fresh air volume of air supply.
7. The concentration of indoor air pollutants such as formaldehyde can be reduced through air exchange dilution. Some of the samples claimed to have the function of removing formaldehyde were diluted by air exchange rather than adsorption and decomposition.
8. On the whole, the overall performance of the 4 samples was rated as five stars, namely: Panasonic (unidirectional flow fresh fan), Gree, Midea, Panasonic (new fan with heat recovery function), 6 samples performed well overall and were rated as four stars, and 5 samples were rated as three stars with average overall performance.
注:
1. The results of this comparative test are only responsible for the test samples, and are not used as the basis for judging whether the product is qualified or not, and no unit shall use the comparative test results for advertising;
2. The evaluation results are expressed with "", "★ ★"The more results, the better, and the products of the same star are ranked in no particular order.
3. "/" indicates that the sample is not marked with the relevant parameter rating.
4. The comparative test samples are all purchased by the staff to simulate the actual consumption, and the marked price is the actual transaction price, which is for reference only.
(2) Detailed analysis of the results
1. There are 2 samples with incomplete air volume ratings, and the measured air volume of the rest of the samples meets the national standard.
The air volume of the new fan directly affects the ventilation frequency in the room, and theoretically speaking, the larger the air volume, the better the ventilation effect. GB/T 34012-2017 stipulates that the measured air volume of a unidirectional flow fresh fan shall not be less than 95% of the nominal value; GB/T 21087-2020 requires that the measured values of the air supply volume and exhaust air volume of the heat recovery fresh air unit shall not be less than 95% of the rated value. The results of this comparative test show that among the 15 samples, 1 unidirectional flow fresh air fan sample is not marked with the air volume rating, and 1 bidirectional flow fresh fan sample is only marked with the rated value of the inlet air volume, but not the rated value of the exhaust air volume.
According to the ratio of the measured value of air volume to the nominal value, the samples of 9 unidirectional flow fresh fans were evaluated, and the samples of 6 new fans with heat recovery function were comprehensively evaluated according to the ratio of the measured value of air supply volume and exhaust air volume to the nominal rated value.
2. The measured noise of the 15 samples is between 31 and 51 decibels.
The noise level is a key factor in evaluating the operating comfort and environmental friendliness of a new fan. The lower the noise of the new fan during operation, the less impact it will have on the lives of residents and make the environment more comfortable. People have different perceptions of noise at different decibel levels.
GB/T 34012-2017 requires that the measured noise value should not be greater than the nominal value, and GB/T 21087-2020 requires that the measured noise value should not be greater than the "rated value + 1dB (A)". The results of this comparative test show that 1 sample is not marked with noise decibel value, and the noise of the other 14 samples meets the requirements of the corresponding national standard. The measured noise of the 15 samples was between 31-51dB(A), that is, the maximum noise was between the hum of the refrigerator and the sound of normal conversation. According to the measured noise value, 15 samples were evaluated, and the samples of Midea and Panasonic brands performed well and were rated as five-star.
The PM2.5 purification (filtration) efficiency of 3.15 samples reached more than 90%.
Purification efficiency and filtration efficiency are indicators to evaluate the purification effect of fresh fans on air pollutants, reflecting the ability of new fans to deal with and purify pollutants such as particulate matter, gaseous pollutants, and microorganisms in the air. The purification efficiency and filtration efficiency are closely related to the quality of the filter screen of the fresh fan, and the higher the purification efficiency of the filter, the purer the air sent into the room. GB/T 34012-2017 divides the PM2.5 purification efficiency into four grades: A, B, C, and D, and the measured value should not be less than 95% of the nominal value, see Table 6 for details, and GB/T 21087-2020 stipulates that the measured value of PM2.5 filtration efficiency of fresh air in ERV (heat recovery fresh air unit) should not be less than 95% of the rated value.
The results of this comparison test show that the measured values of PM2.5 purification efficiency of particulate matter in the samples of 9 unidirectional flow fresh fans all meet the requirements of grade A of GB/T 34012-2017, and the PM2.5 filtration efficiency of 6 fresh air fans with heat recovery function is above 97%, of which 4 samples are marked with the rated value of PM2.5 filtration efficiency of fresh air, which meets the requirements of GB/T 21087-2020 after measured comparison. The PM2.5 purification (filtration) efficiency measured by the 15 samples is shown in the figure below.
According to the measured value of PM2.5 purification (filtration) efficiency of particulate matter, 15 fresh fan samples were evaluated, and the samples of Mijia, Gree, Midea, Philips, and Green Island Wind brands performed well and were rated as five-star.
4. Among the 6 samples of fresh air fans with heat recovery function, 1 sample has a net fresh air supply rate of less than 90%.
The net fresh air rate of the supply air is an index to evaluate the air tightness of the fresh air system. It refers to the ratio of the volume flow rate of outdoor air contained in the supply air of the fresh air fan with heat recovery function to the supply air volume. The higher the clean fresh air rate of the supply air, the greater the amount of clean air entering the room, so as to ensure the purity of the indoor air. GB/T 21087-2020 requires that the measured value of the net fresh air rate of the ERV (heat recovery fresh air unit) with an air supply volume of no more than 3000m3/h should not be less than 90%. The results of this comparative test show that among the 6 samples of fresh air fans with heat recovery function, 5 samples have a net fresh air rate of more than 95%, and the measured value of 1 sample of Green Island Wind brand has a net fresh air rate of 85.8%. The measured net fresh air rate of the 6 samples is shown in the figure below.
According to the measured value of the net fresh air rate of the air supply, the samples of 6 fresh fans with heat recovery function were evaluated, and the samples of Philips and Midea brands performed well and were rated as five stars.
Among the 5.6 samples of new fans with heat recovery function, 5 models of cooling capacity and heat recovery and full heat exchange efficiency meet the requirements of national standards.
The cooling capacity and heat recovery exchange efficiency reflect the ability of the new fan to recover cold capacity and heat. At the same time of completing air ventilation, the fresh fan recovers and exchanges the dirty air discharged outdoors and the fresh air sent into the room to reduce the indoor hot and cold temperature loss caused by air ventilation. Theoretically, the higher the exchange efficiency, the greater the ability of the new fan to recover cold and heat.
GB/T 21087-2020 requires that the measured value of total heat exchange efficiency should not be less than 90% of the rated value, and the cooling capacity recovery ≥ 55% and the heat recovery ≥ 60%. The results of this comparative test show that among the 6 samples of fresh fans with heat recovery function, the cooling capacity and heat recovery full heat exchange efficiency of 5 samples meet the requirements of GB/T 21087-2020, and the measured value of the total heat exchange efficiency of the cold capacity recovery of the samples of the Green Island Wind brand is 42.70%, which is less than 90% of the rated value. The comparison between the cooling capacity, heat recovery and total heat exchange efficiency of the 6 samples and the rated values is shown in the figure below.
According to the measured values of cooling capacity and heat recovery total heat exchange efficiency, 6 samples were evaluated, and the samples of Panasonic and Philips brands performed well in terms of cooling capacity and heat recovery total heat exchange efficiency, and were awarded five stars.
6. Among the 15 samples, 11 samples were incomplete.
The parameter information indicated on the label is one of the main channels for consumers to fully understand the product information and realize on-demand purchase. If the parameter information is incomplete, it will be difficult for consumers to obtain the corresponding product information and make appropriate choices. In this comparative test, it was found that 11 of the 15 samples had incomplete labeling of relevant functional parameters. For example, PM2.5 purification efficiency, air volume, external residual pressure, noise, clean fresh air volume and other core indicators related to the functional effect of the product.
7. Some of the samples claiming to have the function of removing formaldehyde are actually diluted by air exchange, and there is no special functional design.
In this comparative test, it was found that some samples claimed to have the function of removing formaldehyde on the sales details page of the e-commerce platform, but the labels and instructions of the physical samples received from the purchase did not indicate that they had the function of removing formaldehyde and the corresponding parameters. According to the analysis of the sales page and the physical structure design of the sample sales page by laboratory professionals, some of the samples that claim to have the function of removing formaldehyde are actually diluted by air exchange to achieve the purpose of reducing the concentration of gaseous pollutants such as formaldehyde, and the product has a special functional design. By introducing fresh air from the outside and diluting the indoor air, it is true that the formaldehyde in the indoor air can be reduced to a certain extent, but its removal effect depends on the degree of ventilation.
Consumption tips
In order to guide consumers to choose new fans scientifically and correctly, the Guangdong Provincial Consumer Council and the Foshan Municipal Consumer Council issued the following consumption tips to consumers based on the results of this comparative test:
(1) The first thing to choose a new fan is to look at the demand. In areas with a large temperature difference between indoor and outdoor in winter and summer, a new fan with heat recovery function can be selected, which can improve indoor air quality while recovering energy and reducing energy consumption.
(2) Focus on air volume and purification efficiency. These two indicators are applicable to any type of fresh fan and are the core indicators to consider the actual functional value of new fans. Too little air volume can't meet the indoor fresh air demand, and too much air volume can lead to higher costs, resulting in waste of resources. When selecting the air volume, it is possible to consider factors such as the number of air exchanges, the actual ventilation area and the living population.
(3) There is no absolute correspondence between the magnitude of noise and air volume. In the results of this comparative test, it is found that the relative noise value of the new fan sample with small air volume is small, but the noise value of the new fan sample of different brands with the same air volume is also relatively different due to the different engine drive systems. Consumers can choose according to the noise level indicated by the product.
(4) Check whether the relevant index parameters are fully marked. Consumers who buy products with specific index parameters on the product packaging or detail page are given priority, and dare to sign that they dare to promise, which under normal circumstances means that the product has been actually verified in production.
(5) Understand the installation conditions of the new fan. The installation of the new fan involves pipe drilling, and the safety of the wall structure must be considered. It is best to check the building plan in advance and communicate with the property to avoid the impact of punching on the safety and use of the house. Before purchasing a new fan, consumers should communicate with the sales staff or customer service in advance about the housing situation, in case it cannot be installed after purchase, resulting in unnecessary losses.
(6) Pay attention to the working principle of the removal of gaseous pollutants such as formaldehyde. Some products are marketed to remove a variety of indoor air pollutants, such as formaldehyde, bacteria, TVOC (total volatile organic compounds), dust mites, and more. Most of these products reduce the concentration of air pollutants through the principle of air exchange dilution, and there is no special functional design, and the removal effect depends on the degree of air exchange, and consumers should look at relevant advertising rationally.
[Special statement]: The information used in this content is from the authoritative official website. If the relevant sampling results and data are verified and confirmed by the relevant government departments to have changed the facts, please contact this journal in time