At present, there are two new fans with heat exchange functions on the market, one is the full heat exchanger and the other is a heat exchanger. The former is usually “paper” in the former, and the latter is usually aluminum. So there is no aluminum heat exchanger in the world. The general name of the aluminum core is the heat exchanger.
So what are the advantages and disadvantages of the two?
First, we look at the essence of them.
The total heat exchanger is commonly referred to as ERV, the full name is Energy Recovery Ventilation, and is translated into energy recovery ventilation.
The sensible heat exchanger is commonly referred to as HRV, the full name is Heat Recovery Ventilation, and the translation is heat recovery ventilation equipment.
The energy in the air includes the sensible heat (temperature) and the latent heat (humidity), and it is obvious that the total heat exchanger can reclaim the energy as a whole, and that the heat exchanger can only be part of the temperature, which is the essential difference between them.
Therefore, from the energy saving effect, the heat exchanger is not as good as the full heat exchanger, in other words, the popular point, the energy saving effect of the aluminium core new fan is not as good as the paper core new fan.
(2) from the actual installation and Application
There is a concept of “dew point” in the air, that is to say that the surface of the object will be exposed in a certain temperature and humidity state, which is reflected in the new fan. The surface of the so-called object is the surface of the heat exchange core, and the temperature of the heat exchange core will change because the new wind machine is to exchange the indoor and outdoor air. The greater the temperature difference, the higher the risk of condensation. And because the sensible heat exchanger can not adjust the humidity, the risk of condensation is much higher than that of the total heat exchanger. All sensible heat exchangers will be equipped with “draft tube”, because in general, the rate of condensation and frost will probably occur.
The function of the draft tube is to guide the condensation water formed after condensation and frosting.
In the north, it is not advisable to get the diversion pipe outside, which is not advisable, because the north winter outdoor is lower than zero degree is normal, the diversion pipe will inevitably freeze, the pipe freeze can not guide the flow.
3. The total heat exchanger has the function of regulating indoor air humidity.
We take the hot summer humidity in southern China as an example: high outdoor temperature, high humidity (38 degree, relative humidity 90%), low indoor temperature, high humidity (using air conditioning, 26 degrees, relative humidity 90%).
Can we reduce indoor air humidity through the fresh air system?
Sensible heat exchangers must not be able to, because aluminum as an exchange medium is not permeable and can not exchange humidity.
So can the whole heat exchanger be able to do it?
Knowledge point 1: the humidity we usually say is relative humidity. In the case of the same relative humidity, the content of water in the air with high temperature is greater than that of the low temperature air.
Knowledge point 2: water in the air is transmitted through pressure. The pressure is large and the pressure is small.
If there are 3 drops of water in the outdoor air of 38 degrees outside, and 2 drops of water in the indoor air of 26 degrees in the room, then when the two strands of air meet in the full heat exchange core, the water molecules, which have more pressure, will transmit the water molecules to the indoor exhaust side, thus the water molecules in the new air entering the room are less and the humidity is reduced. Coming。
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