December 2015, Northeast China, Beijing, Tianjin and the surrounding areas after another heavy air pollution process appears.
Experts said that most of the time people stay at home, offices and other indoor spaces, indoor air pollution prevention and control can not be taken lightly, scientific understanding of the proper use of air purification means, for the interior space is also put on the “anti-haze masks.”
Purifier significantly improve air quality
“Modern, 80% of the time indoors, when the outdoor pollution, the indoor air purification treatment if done, is not optimistic.” Electronic Engineering, Tsinghua University Associate Professor Zhang expressed.
November 2014 to January this year, the Department of Electronic Engineering, Tsinghua University, Tsinghua University Building Environment Test Center and other units jointly sponsored Beijing indoor air quality research. Zhang is in charge of the research project. Beijing research group collected a total of 407 volunteers 110,000 hours of indoor data, announced the “data analysis reports indoor air quality research.”
The report shows that during the sampling period, the average PM2.5 Beijing outdoor (fine particles) at a concentration of 91.5 micrograms / cubic meter, residents of the average PM2.5 concentration in indoor air was 82.6 micrograms / cubic meter, in light pollution category. 20 hours of exposure to indoor PM2.5 total daily exposure is about 82%, while the outdoor four-hour PM2.5 exposure was about 18% of total daily exposure. Indoor PM2.5 intake per capita is four times the outside.
The report shows that the distance between the main roads can affect indoor air, away from the main road “is more than 500 meters,” “100-500 meters” “is less than 100 meters,” the building, indoor air quality showed a gradual downward trend.
The report also noted that there is a certain correlation between the living-room floor and the concentration of pollutants. During sampling, in almost all 17 floors above the outdoor concentration interval, showed the lowest value of indoor concentration. Outdoor concentration in the range of 0-200 micrograms / cubic meter, the concentration of higher value interior layer 1-8; in the range of 200-400 micrograms / cubic meter, the higher the indoor concentration layer 9-16.
An association exists between the floor and the concentration of indoor pollutants conclusion, to stimulate discussion and questioning. Zhang said that the report presented only data correlation results of the sampling time, “the impact on the indoor air quality of the floor is very complex, with the season, the wind between the floor have a relationship. Want more stringent causal conclusions, the sample size also to continue to expand. this result led to the interest we continue to explore the relationship between the floor and indoor air quality, but it is currently too early to draw conclusions. ”
Distance and main roads, floors and other factors, the impact on air quality is clear, the report notes, whether indoor air purification equipment a greater impact on air quality. Open air purifier indoor air quality plays a significant role in the promotion, regardless of the value of outdoor, indoor value is always maintained at about 15 micrograms / cubic meter.
The best placement itself from closer
Professor, Department of Building Science, Tsinghua University School of Architecture Zhao Bin said, “in all the doors and windows closed, no indoor purification conditions, indoor and outdoor PM2.5 concentrations is 1/3 to 2 / 3.PM2.5 settlement or not all self-digestion, which means that if you do not take purifying means the lowest concentration of indoor air pollution is also the outdoor 1/3 haze serious, or should we turn the air purifier. ”
The proper use of air purifiers to fully play its role.
Zhao Bin said purifier work efficiency depends on the amount of clean air (CADR), per unit time, how much “clean air”. Clean room space required time = (room volume / purifier CADR) × (2 or 3). “For example, a 40 cubic meters of space, if you are using a CADR of 40 cubic meters per hour of purification, then doing a clean indoor air purification takes about 3 hours. Suggest that you be converted at the time of purchase, to match the indoor area . ”
Air purifier placement is very particular. Zhang believes that the best cleaner is located away from the space itself closer. “Now most of the air purifier is monitoring the outlet, but the outlet may not be able to clean air throughout the room .PM2.5 suspension relatively long time, if people in the living room, but the purifier in the bedroom, other rooms doors are open, the air quality around the body will not be improved as soon as possible. the best is where people, put the cleaner on the side, the other unused room doors are closed, surrounding itself guarantee clean air. ”
Air purifiers how long it takes to start work? Zhang pointed out that the data sampling process was observed within 20-30 minutes after the cleaner turned on, indoor air pollution, not fall phenomenon. He speculated that this is due to the presence of indoor air exchange, resulting in the original settlement on the ground of a larger pollution particles into the air, after the pollutant concentration gradually with cleaner work increases. “Based on the presence of secondary dust, we suggest that you turn on the air purifier will not take less than half an hour, but also to maintain a cleaner surrounding sanitation.”
Poor outdoor air quality can be “short window, close the window length”
Experts suggest that different types of purifiers and the use of different frequencies can affect filter replacement time. In more serious air pollution in the region, the use of relatively high frequency, it is best to filter purifier replaced every few months.
“When the cleaner dust rate decreased to 80% of the initial efficiency, or increase resistance 2-3 times when it should be replaced.” Zhao Bin said, “specific determination method, if the open and saw the purifiers filter has been blackened, or gently touch, to see visible signs of dust off, a respect for the core. If you smell bad taste back, is already too late. ”
Professor Zhang Yinping director of Tsinghua University Building Environment Test Center also suggested that “domestic PM2.5 detector can be put out on the air cleaner outlet, if you find small numbers no longer reduce or decline, is the time to replace the filter. ”
When the outdoor air quality index “burst table”, but also ventilation windows do?
Experts said that even if the outdoor air is very bad, crowded indoor places or should choose the ventilation. This is not just because of indoor pollutants PM2.5 in a hermetic doors can be reduced although the haze impact on the human body, but it makes other contaminants, such as carbon dioxide, formaldehyde, nitrogen oxides concentration increases, if the environment has been in a closed, no fresh air circulation, would endanger human health.
“Experiments show that the concentration of carbon dioxide rises, people will feel dizzy discomfort when its concentration reaches a certain height, on human cognitive behavior have a significant impact on the brain’s response rate will decrease. People need to open the window ventilation and air purification find a good balance. “Zhang said.
Zhao Bin believes that the outdoor air quality is poor, it can “short window, close the window long.” For example, when you get up in the morning to leave the bedroom, but a short time window, immediately turn off once returned to the bedroom window open purifier. “A lot of phone APP can view real-time outdoor air quality, people can choose day time relatively good air quality ventilation.”
In addition to the right of purification means, people should focus on their own haze-day cleaning. “Because PM2.5 only through the respiratory tract into the body, exposed to contact with the outer skin of pollution particles will also bring back the living environment, so back to the room from the outside, it is best to clean the skin, mouth and nose as soon as possible.” Zhao Bin said.
The new “air purifier” national standard core indicators
The newly revised “air purifier” national standards this year September 15 release, will be officially implemented March 1, 2016.
The new national standard air purifier to improve the evaluation of two types of basic technical indicators, “the amount of clean air” (CADR) and the “total amount of purification.” “Clean air amount” is the normal indicators, referring to the “capability at rated state and the prescribed test conditions, providing clean air volume” air purifier, which is purified target pollutants (particulate and gaseous pollutants) of ability. “Total amount of purification” is the long-term targets, namely air purifier during continuous operation, “the amount of clean air ‘to decay to half the total amount of the initial value, the cumulative removal of target pollutants. “Clean air amount to” inspect air purifier purification capacity, the “total amount of purification” from the perspective of life to measure the performance of the air purifier.
In addition, the new national standard also adds easy to understand the consumer, to buy all kinds of product identification labels, such as “Application area”, “life” is derived algorithm and parameter descriptions. Additional information is also standardized product labeling should indicate signs, such as the use of the product, replace the filter (cleaning), routine maintenance methods.