1. Do not pay attention to the quality of the motor:
It is necessary to pay attention to the quality of the motor. The quality of the motor may vary several times in its service life. A good motor may have a service life of 15, 20 years or even longer. A poor motor may only have a service life of 1-3 years, and the longer the operation time is, the greater the noise will be. For new machines, no matter the quality of the motor is good or bad, there will be no problem in operation, so it can't be seen at the initial stage, and the key is long-term operation.
2. The quality of the core of the heat exchanger is not concerned:
The heat exchange efficiency is determined by the material and heat exchange area. The price difference between the good material and the poor material will be 20 times or more. The core body is stacked one by one, and the heat exchange area = the area of one piece * the number of pieces. For example: for two cores with the same overall dimension, the heat exchange area with a piece spacing of 2mm is three times of that with a piece spacing of 6mm! Therefore, the larger the size, the smaller the chip distance, the larger the heat exchange area, and the higher the heat recovery efficiency! Ignoring the quality of the core (core) of the heat exchanger, there is no point in buying the heat exchanger. It's just the fuss of the manufacturer, and you can buy comfort.
3. Over belief that the whole heat exchange core can be washed by water:
No matter how much the merchants boast, the main component of the whole heat exchange core is composite fiber. Theoretically, the life span of the material is up to more than ten or twenty years or even longer (if you have to keep the core completely clean to ensure the efficiency and life span). The whole heat exchange core can be washed by water from the material alone, but someone should tell you that once the fiber is dirty, it is very difficult to wash by water, Let alone a piece of internal cleaning how possible? Moreover, once the fiber is under water, the structural pores will change, which will seriously affect the heat exchange performance! So please clean with air gun / vacuum cleaner! Unlike the aluminum core, the metal surface of the aluminum core is smooth and it is difficult to accumulate ash. The normal use of zhonghuifeng dust-free aluminum core does not need to be replaced, and it can be soaked or washed with water at will, without changing the performance and shape.
4. Pay too much attention to the PM2.5 function of the controller:
What we need to breathe is clean and oxygen rich air PM2.5. The main source is the outdoor air rather than the indoor air. Only to prevent the outdoor dust from entering the indoor is the key! In the case of closed doors and windows, after the fresh fan with purification is opened, PM2.5 can be reduced to a clean level within a period of time. As long as the doors and windows are kept closed, the air can be kept clean, and the PM2.5 value changes little. If the fresh air fan is automatically started or stopped according to PM2.5 index, when the air is clean, the fresh air fan will stop working or running at a low speed. At this time, the CO2 concentration may start to rise continuously, the oxygen will be less and less, and there may be lack of oxygen in the room. Therefore, the control of indoor CO2 is fundamental, not putting the cart before the horse. More attention should be paid to the control of CO2 System.
5. It is not possible to distinguish between "unloader" and "sufficient machine":
"Material reducing machine" is sometimes called "engineering machine" or "real estate machine". It is a machine made with the lowest material cost. In order to reduce the cost, it even makes its own winding copper wire as the motor, replaces hot paper as the core with ordinary paper, and replaces new materials with recycled materials, etc. There are two kinds of "material reducing machine", one is to make the size smaller and all things smaller; the other is to make and package the appearance with normal size and beautiful appearance, and all the materials inside are the cheapest. Especially, pay attention to the inferior gold and jade and sell them at a high price. In order not to be complained, the air volume of the "material reducing machine" will be basically guaranteed.