Air Humidifier PM2.5 is misunderstood

In the dry winter, a humidifier with a dense mist has become a must for many families. However, on February 10th, CCTV-4 "China News" column, a news that "the use of humidifiers is not easy to become a "healthy killer"", so many people who often use humidifiers panic. In the report, CCTV reporters conducted PM2.5 tests on rooms before and after humidification. Using a portable PM2.5 tester, the experimenter first measured the PM2.5 value in the room before the humidifier was used, which was 0.133 mg/m3. Then, mineral water, tap water, and distilled water were placed in a humidifier, and the indoor PM2.5 value after humidification was measured. As a result, it was found that after humidification with mineral water, tap water, and distilled water, the results were 0.211 mg/m3, 0.363 mg/m3, and 0.176 mg/m3, respectively, which were significantly increased compared with the previous background.

Does the humidifier really increase indoor PM2.5? The reporter verified this with Peng Yingdeng, a researcher at the National Urban Environmental Pollution Control Technology Research Center. He responded that there is no need to refuse to use the humidifier for fear of PM2.5. Because the humidifier not only does not harm health, but can effectively improve indoor humidity and increase negative oxygen ions.

Regarding the design and results of the experiment, he said that there are certain problems. On the one hand, the portable PM2.5 detector used in the experiment is not particularly professional, and the data obtained by the test is not necessarily accurate. On the other hand, even if a professional testing instrument is used, it will cause misunderstanding of the test result due to the inherent defects of the detection technology. This is because the working principle of the humidifier is to cut water into water vapor aerosol particles, and PM2.5 is essentially an aerosol particle. The current detection technology cannot effectively distinguish between vapor particles and harmful particles. Aerosol particles (PM2.5). Moreover, the automatic PM2.5 testing instrument can not completely dehumidify, naturally can not avoid the interference of water vapor, the water mist sprayed by the humidifier will be mistaken as PM2.5. However, the water vapor particles are different from the harmful PM2.5. It is a beneficial aerosol particle, so the PM2.5 detection value in the room after using the humidifier is increased, but it does not harm the body. Therefore, if you don't feel uncomfortable and uncomfortable, then the sudden increase in PM2.5 in your home is likely to be only the interference of water vapor, so don't worry too much.

For the test results using three different water quality tests, Peng Yingdeng said that no matter what kind of water is added to the humidifier, the aerosol particles will be detected. However, the PM2.5 values detected using different water quality do vary, especially tap water, which increases the value of PM2.5 in the air by nearly three times. This is because the tap water contains calcium and magnesium ions and some impurities, and the generated aerosol particles can more significantly increase the PM2.5 mass concentration. It should also be noted that, unlike distilled water, these impurities do have a certain negative impact on health after they are sprayed out with mist. Therefore, Peng Yingdeng suggested that it is best to use distilled water or purified water with less impurities and safer, and use tap water as little as possible. Moreover, the use of the humidifier should be adequate, not the larger the opening, the longer the opening time, the better the effect. According to the most suitable standard for human body, the indoor humidity is preferably controlled at 45% to 55%.

Finally, for the indoor pollution problem that people have been worried about, Peng Yingdeng reminded that indoors is a closed space, it is easier to accumulate PM2.5, but the most fundamental protection is to ensure the forced exhaust of the kitchen and toilet, and often open the window for ventilation. To keep fresh air flowing.