There are many countries and regions that are foggy frequently. Moreover, the air is polluted a lot in almost all countries. That’s why many companies have begun paying more attention to making products that can somehow solve this problem. Among those products, we should mention the air purifiers. In fact, air purifiers have many unavoidable problems. Because they are closed, the concentration of carbon dioxide in indoors remains too high for a long time. The air purifiers with small size are noisy. The noise is small, but the space is small, and there is air. The purification area of the purifier is limited.
What is the difference between a fresh air system and an air purifier?
Nowadays, a new product called the fresh air system is used in large quantities in enterprises and homes. We believe many people have heard of the fresh air system during the renovation, but they don’t know the difference with the air purifier.
The so-called fresh air system extracts the outdoor air through the pipeline and filters through the machine to enter the room. At the same time, the new air blower will make the indoor air pressure slightly larger than the outdoor, and the indoor air will slowly leak out through the gap to achieve the purpose of purifying and circulating air.
To make an analogy, automotive air conditioners have two modes: inner circulation and outer circulation. The inner circulation is like an air purifier, which purifies and circulates indoor air in a confined space. The outer circulation is like a fresh air system that draws in and purifies the outside air.
In the actual use, the air purifier has a good purifying effect in a confined space. But when people are in a closed environment for a long time, it is easy to cause indoor hypoxia and excessive carbon dioxide. If the fog is caught up, it is unrealistic to open the window. With the fresh air system, you can complete the ventilation without this trouble, removing the cockroach at the same time. In addition, since the indoor air pressure is slightly higher than the outdoor, the outdoor polluted air enters. So these systems are also beneficial to the discharge of harmful substances such as formaldehyde.
The disadvantages of the fresh air system are high cost and troublesome installation. The entry-level products are priced over four or five thousand yuan, while the high-end models cost around tens of thousands or even hundreds of thousands. Moreover, the higher the products, the higher the installation requirements.
So if summarize the current problems of the fresh air system, we can say that they are expensive, need to make a relatively large modification of the house, and consume much electricity.
The time for Xiaomi to enter the empty field is not too short. Since 2014, a series of products including air purifiers, car air purifiers, masks, and other air quality products have been introduced. Their biggest selling point is the cost-effectiveness. Recently, Xiaomi has set foot in the market of the fresh air system, and launched a Mijia new fan, with a crowdfunding price of 1999 yuan ($289).
On the eve of the release, Xiaomi organized an experienced event. Let’s take a look at the 1999 yuan Mijia new fan.
Is it easy to install?
At present, the fresh air systems are divided into two major categories. First, it refers to the central fresh air. Its installation method is similar to the central air conditioner and should be installed together when the house is renovated. Because of the strong correlation with the purchase and the decoration seasons, and the high price, there is always a very small choice of this kind of products and it is basically exclusive to local tyrants.
The Mijia new fan that we are reviewing belongs to the category of a single fan. It adopts the wall-mounted design. It only needs to be punched on the wall. After installation, it can be connected to the power supply. The installation cost is much lower than the central fresh air systems.
Since the place we have experienced has already installed the Mijia new fan, there is no way to elaborate on the detailed installation process. In fact, the Mijia new fan is like an enlarged Xiaomi Purifier Pro, and the official does not provide too detailed dimensions. From the visual point of view, the size of the Mijia new fan is similar to that of the commonly used wall-hung boiler in the home. As long as there are enough distances on both sides of the window, it can be installed. In addition, according to the official introduction of Xiaomi, Mijia new fan supports a variety of installation methods including glass opening, which eliminates the user’s influence on the wall to affect the original interior decoration or property.
In short, for the majority of users, the installation of Mijia new fan will not be an obstacle. You should pay attention to other things – is your bedroom hanging a similar thing to the fireplace? Is it acceptable? Also, you have to cut a hole in the size of your bowl on your wall.
Objectively speaking, the value of the Mijia new fan is not bad, but it has no special features in design, and there is no slot. It is suitable for matching ‘cold and modern’ style decoration.
The outer casing is made of the same engineering plastic as the Xiaomi air purifier. The matte texture is easy to clean. The key is that it will not yellow when used for a long time.
Under the fuselage, there is a logo of Mijia. The middle part of the fuselage carries an OLED touchscreen. The air condition can be intuitively understood from the numerical value and the outer aperture. On the left side of the screen, there is the light adjustment button, and the right side has the power switch/mode selection button. It is basically the same as the operation logic of the Xiaomi purifier.
On the right side of the fuselage, there are three sensors of PM2.5, CO2, and temperature/humidity. The Mijia new fan uses Swedish imported Senseair’s CO2 sensor and Plantower laser PM2.5 sensor, allowing users to view indoor air quality data in real time through the Mijia App anywhere.
For new fans, it is very important to change the filter. After all, the filter is a consumable. If it is not replaced regularly or it is not easy to clean, it will not achieve the effect of ventilation but will have side effects.
The Mijia new fan adopts a triple filter structure: anti-mosquito filter, medium-effect filter, and H13 high-efficiency filter. The anti-mosquito filter adopts a mesh box design, which can be washed directly with water without replacing the consumables.
The second layer is the medium efficiency filter. The official removal rate of PM0.4 is 80%. Pollen, smoke and so on will be blocked by this layer. Most of the PM2.5 will stop here.
The last layer is the HEPA13 high-efficiency net, which can filter PM0.3, including some bacteria, germs and so on. After layer filtration, it is basically guaranteed that the air entering the room is safe and clean enough.
The operation of replacing the filter material is also very simple. The three-layer filter screen is designed on the front of the fuselage. You just need to fasten the buckles on both sides with both hands. This action will trigger the product to stop automatically and ensure safe use. If it is used continuously, Xiaomi recommends the medium-effect filter to be replaced once every 3 months, and the high-efficiency filter should be replaced once every 6 months. The mosquito screen can be cleaned according to the situation.
In line with the principle of other single air blowers, the Xiaomi fresh air system also relies on the principle of supplying air into the house and manufacturing indoor micro-positive pressure for air exchange. The effect is equivalent to opening the window under the condition that the outdoor air is extremely clean, and the air outlet is in the fuselage. At the top, this operation mode is very beneficial for the dissipation of persistent volatile gases such as formaldehyde and TVOC. Although traditional activated carbon can also adsorb such substances, once it is saturated, it loses its effect, and the overall effect is not on the order of magnitude with the new fan. Therefore, for newly renovated homes, the use of new fans is more advantageous than other products.
How about the purification effect?
Of course, although the installation is simple and convenient, the most important thing is to actually use the effect. (Note: The following test data is provided by Xiaomi official.)
The environment we tested comes with a total area of about 100 square meters. The Xiaomi fresh air system was installed in the master bedroom and the area was about 18 square meters.
Air volume is often a direct factor affecting the applicable area of fresh air, purification speed and so on. It is also one of the performance parameters that people are most concerned about. Popularly speaking, it is the amount of air measured at the air inlet, which refers to the volume of outdoor fresh air entering the room every hour. Somatosensory, the greater the amount of air, the more fresh air is entering.
Compared with the CADR description of the air purifier, it may be more straightforward. In fact, the air volume is more suitable for the user in the applicable area and is similar to the air conditioning horsepower parameter.
The air volume of the Mijia new fan is 300, which is a relatively mainstream level.
First, let’s test the concentration of carbon dioxide. Compared with PM 2.5, the harm of carbon dioxide is usually easier to ignore. When the doors and windows are closed, the indoor air cannot be replenished, and the carbon dioxide will accumulate slowly and the concentration will become higher. There is a set of data here that feels uncomfortable when the carbon dioxide concentration exceeds 1000 ppm.
1. 350~450ppm: same as the general outdoor environment;
2. 350~1000ppm: fresh air and smooth breathing;
3. 1000~2000ppm: we feel the air is turbid and start to feel drowsy;
4. 2000~5000ppm: Feeling headache, lethargy, sluggishness, inability to concentrate, rapid heartbeat, mild nausea;
5. Greater than 5000ppm: May cause severe hypoxia, causing permanent brain damage, coma, and even death.
Through a series of painstaking operations, the indoor carbon dioxide concentration successfully reached 4646ppm, and the Mijia new fan was opened to the highest level for 30 minutes, the concentration of carbon dioxide was reduced to 471ppm, which was transferred to a good state.
TVOC is also very harmful to the human body. TVOC is a general term for indoor volatile organic gases other than carbon monoxide, carbon dioxide, carbonic acid, and carbonate.
From the actual test, at 15:17, the TVOC concentration reached 3.52 and exceeded the standard. The highest level was opened, and the score was reduced to 0.578 at 15:49. The whole process took about 30 minutes.
It can be seen that the Mijia new fan is still very effective in removing TVOC because it is the most effective way to deal with this continuous volatilization of gas. So the new fan gradually brings TVOC to the outside in indoor and outdoor air exchange. It is necessary to install a fresh air system in a renovated house.
The air quality index PM2.5 (unit: ?g/m3) indicates the amount of particulate matter that can enter the lungs per cubic meter of air. The Mijia new fan also has a certain effect on the removal of PM2.5.
Before opening, the indoor PM2.5 index reached 514.1?g/m3, which was a serious pollution level, and dropped to 0.1?g/m3 after 20 minutes.
Is the noise loud? Is it quite expensive?
Noise and power consumption are also very important factors. In the noise part, if the highest level is turned on, the noise is still very obvious and basically cannot be tolerated.
However, the Mijia new fan automatically adjusts the air supply volume according to the indoor air quality. There is also a sleep and favorite mode. The user can switch to sleep or favorite mode through the mobile client. Sleep mode can enjoy ultra-low noise operation, while the favorite mode sets the most comfortable air volume.
There is almost no noise in the automatic mode, which is ideal for all-weather operation.
The high power consumption of the Mijia new fan is only 35W. After accounting, even if it is open at the maximum gear all day, it only consumes about 0.84 kWh in 24 hours.
However, it is necessary to specify that the Mijia new fan is equipped with an electric auxiliary heat function of up to 800W in the third gear. When the electric auxiliary heat function is turned on, the operating power of the Mijia new fan is 335W, 535W, and 835W, respectively. When used in winter, the power consumption is still a bit high.
The last question is, is it a new fan or a purifier?
- a) Look at the area. The fresh air system has limited space for purification. So a small apartment or a separate bedroom is good. Most of the houses are more suitable for buying several purifiers.
- b) Look at the demand. The fresh air system is most suitable for installation in a newly renovated room, which can quickly and effectively remove harmful substances of formaldehyde while purifying the air. The old houses differ from person to person.
Taking the air quality problem as an opportunity in recent years, the air purifiers have become a popular category. In more families, enterprises and even service places, we can see many air purifiers. In contrast, fresh air products have always been tepid in the market. Among them, the chaotic pricing of four or five thousand or even nearly ten thousand yuan is an important reason to keep buyers out. Similar to many industries that are in the lead-in period, the new wind industry also needs a cost-effective and popular product to truly activate the market.
The price of the Mijia new fan is not high, the installation is simple and convenient, and the threshold of the fresh air system is lowered to some extent. If you have a large population and ample installation space, the 2,000-yuan Mijia new fan is worth considering.