CAD (Computer Aided Design) was born in 1960s. It is a research project of interactive graphics proposed by MIT. Due to the expensive hardware facilities at that time, only General Motors and Boeing Airlines of the United States used self-developed interactive drawing systems.
I wonder how he introduced you. Should be a fool! Improving one's social status with words that the public can't understand is the most commonly used deception in sales. ...
With smog and PH2.5 (fine particles-particles that can enter the lungs; "2.5" of PM2.5 means 2.5 microns, 1000 microns = 1 mm, and 2.5 microns is equivalent to 1/20 of the hair diameter. Therefore, fine particles with a diameter of 2.5 microns are invisible to the naked eye. Terms such as formaldehyde are becoming more and more familiar, and air purifiers are becoming more and more popular. However, after eight years, the road is long and Xiu Yuan is Xi. I have to say that the air purifier is still very messy.
If you want to buy a home air purifier that suits you, please read and think about this short article carefully:
You may never think: Is there a problem for air purifier manufacturers to produce air purifiers of the same brand, different models and different prices?
Have you ever thought: If the low-cost air purifier produced by a factory can meet the requirements of air purification?
If you can?
So is it necessary to produce high-priced air purifiers?
And much more expensive?
However, if the high-priced air purifier can really meet the air purification standards?
So selling low-priced air purifiers has become a deception to fool customers, right?
In order to adapt to the market, is the enterprise that sells regardless of whether the quality is up to standard trustworthy? It may be said that our low-end products have actually reached the standard, and the high-end products are just more perfect in function (nonsense, in fact, he is telling you that it is the same whether it is used or not, and the effect is not obvious anyway)
So choosing an air purifier is the same as choosing a water purifier.
The price is not important, the brand is not important, the only important thing is the effect!
Imagine: even if you only spent 200 yuan to buy an air purifier, but you spent 200 yuan to buy an air purifier, it doesn't work! That's a waste, 200 yuan. Do you think so?
How to choose an economical and efficient air purifier? You can refer to the following important indicators to buy:
Technology is purification technology, and it is the primary factor that should be considered when purchasing air purifiers.
1. See purification methods: The purification methods currently used include the following four categories.
Physical filtration represented by activated carbon and HEPA screen filtration technology is the safest and most efficient filtration method at present.
The filter screen of this air purifier is the core component, and its quality directly affects the purification effect of the air purifier.
First of all-pre-filter, which must be installed in any air purifier. If you don't believe me, you can take it apart (a black filter like a mosquito net is used to filter out large floating objects; Such as: dog hair, wool and so on. There is nothing to say technically, everything is perfect. After all, air conditioners and other equipment have been used for decades, and the effect is similar.
Secondly, as one of the core components of the air purifier, the high-efficiency filter screen determines the quality of the air purifier.
Different filter element grades have different purification effects. The higher the grade of HEPA mesh, the smaller the diameter of particles that can be filtered, and the better the filtering effect.
At present, the common air purifiers on the market all use HEPA nets of H 10 and H9 (the standard HEPA filter can filter particles as small as 0.3 microns in the air, claiming that the theoretical filtration rate is as high as 99.97%, that is, the single filtration effect). Due to technical differences, the actual filtration rate in closed environment ranges from 25% to 60%, which refers to the reduction ratio of indoor pollutant content, which is what consumers think is so-called filtration. The following is the same explanation! !
High-end air purifiers generally use HEPA nets of H 1 1 and H 12 grades (HEPA high-efficiency filter can filter particles as small as 0. 1 micron in the air, claiming that the filtration rate is as high as 99.99%), and the actual filtration rate is between 70% and 80%.
Very few high-end air purifiers use H 13 grade HEPA filter (HEPA high-efficiency particle filter, with a minimum diameter of 0.009 micron and an air filtration rate of 99.99%), and the actual filtration rate is 96%. The HEPA net with grade H 13 is the top imported medical-grade clean soft HEPA filter with the best filtering effect. This technology will greatly increase the production cost of other companies, because R&D company will apply for patent protection.
Finally-odor filter, the common method now is to filter odor with activated carbon, which is also one of the core components of air purifier.
Granular activated carbon mesh box: activated carbon particles are simply filled as odor filter, with low cost; The single use time is short, and the purification effect is single.
General activated block carbon: directly processed and shaped, smaller in volume and longer in service life than granular activated carbon with the same weight; However, production is complicated and expensive.
High density activated carbon: the heavier the same volume and mass, the better the adsorption effect; As R&D company will apply for patent protection, the production costs of other companies will increase greatly.
According to related research, the adsorption area of activated carbon with the weight of 1g can reach 500- 1.500 m2, while the weight of high-density activated carbon filter screen is 1.900g, and the adsorption area is about 1.6m 2, which is equivalent to the area of 224 football fields.
Chemical decomposition and filtration represented by photocatalyst and cold catalyst technology can decompose harmful gases while purifying;
Photocatalyst, as its name implies, literally means light, contact and catalysis. It is because more than 30 years ago, Japanese scientist Professor Fujishima Akira discovered that titanium dioxide can make the surrounding air have very strong oxidation reaction ability after being irradiated by light, and can oxidize the surrounding organic matter (such as formaldehyde and benzene) and decompose it into water and carbon dioxide.
Cold catalyst, also known as natural catalyst, is a new type of air purification material after photocatalyst deodorizing air purification material. It can catalyze the reaction at room temperature, decompose various harmful malodorous gases into harmless and odorless substances at room temperature and pressure, change from simple physical adsorption to chemical adsorption, decompose at the same time of adsorption, remove harmful gases such as formaldehyde, benzene, xylene, toluene and TVOC, and generate water and carbon dioxide.
No matter whether photocatalyst or cold catalyst is in the process of catalytic reaction, additives do not directly participate in the reaction, nor do they change or lose after the reaction, so they play a role for a long time (economical and applicable, which can greatly save the subsequent costs).
But personally, there is a potential safety hazard: the manufacturer claims that photocatalyst or cold catalyst itself is non-toxic, non-corrosive and non-flammable, which greatly prolongs the service life of adsorption materials (I also agree that the reaction products are water and carbon dioxide, although there is no secondary pollution, but if personal living habits lead to sleep, will carbon dioxide poisoning occur when doors and windows are closed? Perhaps this is a consideration for big brands to choose to maintain higher physical filtration in the later stage?
Please don't open the doors and windows and such nonsense. Do you want to purify your own air or the air of the earth? Think about it. If such a small purifier for purifying the earth's air is obviously very weak. ...
Ion technology, represented by negative ion and silver ion technology, can sterilize and effectively purify the air;
All ion technologies will release a large number of charged ions into the air for air sterilization. The advantages are that charged ions can sterilize, and adsorption on the dust surface can help the filter screen absorb fine dust particles, and can also play the role of humidifying air and drying air after long-term use.
However, ion ion technology alone is not enough to meet the purification requirements of high-end purifiers, and various filter screens must be installed to assist. Generally, it includes pre-filter, deodorizing activated carbon filter (used to remove ozone, which needs to be replaced in time), in addition to formaldehyde filter (absolute gimmick filter), dust-collecting HEPA filter, etc. Don't these filters need to be replaced? Obviously, only the physical filter can remove air pollutants such as bacteria, viruses, formaldehyde, odor, oil smoke, dust mites, second-hand smoke and so on. Is there an extra charge for ion technology?
Personal qualifications are dull and difficult to understand, and those designers have to complicate simple things. ...
Electrostatic dust removal, mainly relying on electronic dust removal, will produce ozone and bring secondary pollution.
A certain amount of ozone can kill bacteria and viruses and decompose gaseous pollutants, but excessive ozone is harmful to the body, affecting the lungs, leading to asthma and serious cancer.
We should choose three kinds of air purifiers: physical filtration, chemical decomposition filtration and ion technology. Personally, I think physical filtration technology is the first choice. In order to ensure that the purification effect of low-end machines is insufficient, try to choose an air purifier with multiple purification technologies.
An ordinary physical air purifier has a good dust removal effect, but the effect of removing volatile organic compounds and formaldehyde is not as good as that of dust, so conscientious merchants only indicate the CADR of dust.
An air purifier using photocatalyst and cold catalyst technology has obvious effect of removing volatile organic compounds and formaldehyde, which has potential safety hazards.
The purification efficiency (CADR) value of a high-quality air purifier has three indicators:
1, solid particles, also known as particles, are usually simulated by cigarettes in China, so they are also called soot.
2. Volatile organic compounds (VOC), usually using toluene as the test source.
3. Formaldehyde (formaldehyde)
Copy:
Three pollutants in indoor air
① Biological pollutants
Small in size, but wide in spread and fast, it is easy to cause allergic reactions such as sneezing, eye discomfort, cough and asthma.
Bacteria, viruses
It has a huge scale, a wide spread and a very fast spread, which is easy to cause many diseases.
fungal spore
It is easy to spread and breed in the air in humid and warm areas, and long-term contact is easy to cause allergies and asthma.
Dust and dust mites
Dust makes people uncomfortable to breathe and is a hotbed of dust mites and fungi. Dust mite is an active small insect, which often grows on mattresses, sheets, furniture or suspends in the air, increasing the chance of asthma.
pollen
Flowers outdoors or even in vases will produce pollen, and allergic people will have obvious discomfort to respiratory tract, eyes and skin after inhalation.
Pets, human hair and dander
Very small, easy to enter the human respiratory system, providing favorable conditions for the reproduction of dust mites and fungi.
2 smell.
From pets, cooking, garbage and people. Bad smell, affecting home life and neighborhood environment.
③ Chemical pollutants
From cigarettes, decoration works, cleaning products and furniture, long-term contact will irritate the skin, nerves and respiratory tract and bring health hazards.
Secondhand smoke
It was identified as a class A carcinogen by the US Environmental Protection Agency and the International Agency for Research on Cancer. It contains hundreds of toxic substances and carcinogens such as carbon monoxide and formaldehyde, which is particularly harmful to children whose lungs are still developing.
formaldehyde
Splints, pressed boards, urea-formaldehyde resin products and floors in daily furniture are classified as harmful carcinogens. High concentrations of formaldehyde can irritate eyes, nose and respiratory system, and even cause asthma in severe cases.
Benzene series
Include benzene, toluene, xylene, etc. Some of them are identified as carcinogens by the World Health Organization. It mainly comes from organic solvents of various building materials, such as paints, coating auxiliaries, wallpapers, carpets, synthetic fibers, etc. Long-term exposure can lead to chronic poisoning, neurasthenia and blood system symptoms. In severe cases, aplastic anemia, even leukemia and death may occur.
Radon gas
From soil, rocks and granite. Radon is colorless, odorless and difficult to detect. Radon decay products will accumulate in the lungs, which is the second leading cause of lung cancer, second only to smoking.
2. Look at the clean air volume: the greater the CADR, the larger the purification area of the air purifier and the more purification cycles. The international standard is to circulate five times per hour (for example, if there is an air purifier with a clean air volume of 450m3/h, the applicable area of the air purifier is 450 ÷ 5 ÷ 3 = 30m2 according to the room height of 3m. When purchasing, we should consider whether the clean area of the air purifier matches the room area. If the cleaning area is smaller than the room area, the expected cleaning effect will not be achieved. So try to buy an air purifier with a large amount of clean air.
Reference value:
190 m3/h 190÷5÷3 = 12.66 m2。
200 m3/h 190÷5÷3 = 13.33 m2
250 m3/h 190÷5÷3 = 16.66 m2
300m3/h 190 ÷ 5 ÷ 3 = 20m2。
350m3/h 190 ÷ 5 ÷ 3 = 23.33m2。
400m3/h 190÷5÷3=26.66 m2。
450m3/H 190 ÷ 5 ÷ 3 = 30m2。
500m3/h 190 ÷ 5 ÷ 3 = 33.33m2
550m3/h 190 ÷ 5 ÷ 3 = 36.66m2
This value must be marked with the CADR value indicated on the outer package of the air purifier (although many salespeople will interpret it as "190 cubic meters/hour", which is true, but it will mislead some consumers into understanding it as purifying the environment of 190 cubic meters).
2. Look at the structure of the body: Does the air purifier need air exhaust? But what kind of ventilation is more scientific and reasonable? At present, the air inlet and outlet modes of air purifiers are mainly divided into four categories.
Air in the back and air out in the front-this way is easy to blow up the dust on the floor and aggravate the dust in the indoor air (personally, I suggest not to buy it)
Front wind or left and right exhaust and rear exhaust-it is as easy to blow up the dust on the floor as above, which will aggravate the dust in the indoor air (I personally recommend not to buy it).
In the air below or behind, the air comes out from above-this way, the dust on the floor can be sucked into the air purifier, and then fresh air (like cabinet air conditioner) can be blown out from above to play the role of "cleaning the floor" (sales also emphasize: especially if there is a baby at home, the baby likes to climb on the ground, and it is necessary to pay more attention to floor hygiene). However, this seemingly very good technology, personally think there should be defects? Downwind If the baby is lying near the air inlet and does not breathe dust, the power of the motor determines the so-called cleaning range.
Very limited, in other words, if the air purifier has been used at home, there will be no dust accumulation on the ground, which has been filtered and left in the equipment! !
If this technology is a high cabinet like central air conditioning, which is higher than the breathing line of people standing or sitting, you can breathe clean air at the first time, which is nothing. But what about those devices that are smaller and lower than the breathing level? You won't crawl and breathe on the ground like a baby, and the purified air will soon circulate below, causing unnecessary energy consumption and compressing the purified space.
So I personally think that this technology has design flaws.
Upward exhaust-air enters the lower part of the equipment or the whole machine, and clean air is exhausted upward, instead of being blown out from above (ingenious design for equipment below the breathing line; Moreover, the upward air supply will soon spread out on the roof to form a circulating network, which will speed up the air flow, shorten the purification time and expand the purification space. It should be the most scientific way at present, but I wonder if this design can be patented (if so, other companies will have to increase production costs if they want to use this technology). This outlet method must include two different inlet methods:
1. At the same time, introduce ambient air, and exhaust clean air from the middle of the equipment with an annular filter screen (it must be placed in the middle position to achieve the maximum effect; If placed in the corner, it will affect the purification time extension)
2. The front air inlet and the rear air outlet (such as Yixin air purifier) are placed in narrow spaces such as walls and corners, which will not affect its filtration efficiency.
3. Look at the mute motor: Many people ignore its importance, but it is the core component of the air purifier.
How many cubic meters of clean air can be output per minute is determined by it;
At runtime, the sound generated is determined by it;
95% power consumption is also determined by it;
4. Look at the convenience of use: Whether it is convenient in the use of air purifiers is also an important indicator to determine the quality of air purifiers.
Replacement-Whether it is convenient to replace the filter element.
Some inferior or low-end air purifiers boast that their air purifiers don't need to be replaced in order to make people feel convenient and save trouble. This is definitely fooling consumers. How about a high efficiency filter? It must be replaced after a period of time, and air purifiers of any technology must use high-efficiency filters.
Tip-Since the filter element should be replaced, when to replace the filter element has become the focus of attention.
Low-end products will not prompt the service life of the filter, and it is entirely up to the user to estimate or replace it according to the instructions (so that even if the filter fails and fails to meet the purification requirements, the user does not know to use the invalid equipment as usual; How terrible! )
High-end products provide template indicator light to remind users whether the filter element needs to be replaced.
Convenience-different technologies will also bring different experience when used, which is mainly reflected in the independent intelligent mode of air purifier. Appropriate reduction of power and appropriate increase of power need related induction technology support (I'm really sorry that I don't understand it very well and don't explain it too much).
5. Look at the company's word of mouth: Through the above understanding, you should have a very clear understanding of buying an air purifier. For a big brand company, it is the company's responsibility to maintain the brand image! I will not smash the word-of-mouth and signboard that I have worked so hard to build! !
6. Look at patented technology: the patented technology here refers to world-class patents (not everyone in the market can use it, everyone is using it).
Protection period of patented technology: 20 years for invention patents, and 10 year for utility model patents and designs from the date of application. During the period, others have no right to use it. If the protection expires, they can apply to the patent applicant or unit for authorization and pay the fee (it will be the technology used by everyone in about 30 years, and it will be free at this time). So the technology that everyone is using in the market can be regarded as outdated technology. !
7. Look at the authoritative certification: AHAM quality certification, Energy Star certification, Tsinghua University Building Environment Testing Center performance testing and other authoritative certifications are enough to prove superior quality.
AHAM is the abbreviation of American Household Appliance Manufacturers Association, and its certification standard of clean air volume (CADR) was adopted by American National Standards Institute (ANSI) at 1988, which is the certification standard of small air purifier equipment and becomes the most important test index of air purifier efficiency. Products that meet the AHAM standard must be tested by a third-party laboratory and re-examined every year before the AHAM certification mark can be marked on the fuselage and outer packaging for consumers to identify.
The Energy Star certification standard of the US Environmental Protection Agency is that the US Environmental Protection Agency cooperated with the US Department of Energy in 1992 to establish energy-saving standards with 1000 manufacturers, such as joint manufacturers and retailers, in order to make energy-saving and efficient products, so as to achieve the ultimate goal of reducing carbon dioxide emissions and improving environmental quality. The power consumption of products that meet its certification standards must be at least 35% lower than the average power consumption standard of commercial air purifiers.
Relying on the School of Architecture of Tsinghua University, Tsinghua University Building Environment Testing Center has a large number of advanced experimental equipment and follows a strict quality management system. The center has been recognized by China Metrology Certification (CMA) and China National Accreditation Committee for Conformity Assessment (CNAS), and its air testing and assessment report has legal effect.
8. Look at sales: A good salesman will give you a detailed introduction of the air purifier he sells and its comparison with other similar products, as well as the performance advantages and disadvantages of various devices, instead of blindly advocating his own products.
9. Look at after-sales: A good brand has a perfect after-sales system (however, this often requires the real purchase of products, and the use problem can only be realized if you are satisfied)
Not much to say here. If you need an air purifier, you can click on the blue word below the answer and contact me in the first row of Amway Puzzlers private letters.