Concepts of Total Heat Exchange and Sensible Heat Exchange and Their Structural Differences

I. Concepts of Total Heat Exchange and Sensible Heat Exchange
The cooling capacity in air conditioning is divided into sensible cooling capacity and latent cooling capacity.

The manifestation of the sensible cooling capacity is the decrease in the dry bulb temperature, and the manifestation of the latent cooling capacity is the decrease in the wet bulb temperature or relative humidity. The application of total heat and sensible heat exchangers is mainly aimed at achieving the goal of energy conservation during air conditioning. The energy recovery of a total heat exchanger includes the energy of sensible heat exchange, and there is also the energy exchange of latent heat. Therefore, the efficiency of a total heat exchanger is higher than that of a sensible heat exchanger.

However, under extreme working conditions, when the indoor humidity is high, the outdoor temperature is low, and lower than the dew point temperature of the indoor air, the phenomenon of condensation will occur.

II. Structural Differences between Total Heat Exchangers and Sensible Heat Exchangers
A sensible heat exchanger is a type of heat exchanger. It can only exchange heat and cannot exchange humidity. While a total heat exchanger can exchange both heat and humidity, and each has its own advantages.
The dehumidification effect of a sensible heat exchanger is not obvious. More precisely, the dehumidification of all heat exchangers is actually the removal of moisture, and the moisture removal effect of a total heat exchanger is relatively obvious. The most fundamental function of both is to exchange fresh air, and dehumidification is only an auxiliary function. Of course, a dehumidifier is the best choice if you want to dehumidify fundamentally.
The only difference between sensible heat and total heat lies in the filter core. The core of a sensible heat exchanger is made of aluminum, and the core of a total heat exchanger is made of paper. According to certain principles, sensible heat is better than total heat. The aluminum core of the sensible heat exchanger is corrosion-resistant, easy to wash (just rinse it directly under clean water when it gets dirty), has a long service life, and is resistant to extrusion. However, after the paper core of the total heat exchanger is corroded by the moisture and dust in the air, it will block the ventilation openings and cannot be cleaned. This leads to poor ventilation effect and ineffective moisture removal. The simplest solution is to replace the paper core.
A total heat exchanger enables the hot and cold transformation of media at different temperatures.

Its function is to achieve the service temperature of different media through the heat exchanger. There is no restriction on the installation location as long as the equipment can be used.
During operation in summer, the fresh air obtains cooling capacity from the exhaust air of the air conditioner, reducing its temperature. At the same time, it is dried by the air from the air conditioner, reducing the moisture content of the fresh air.

During operation in winter, the fresh air obtains heat from the exhaust air of the air-conditioned room, increasing its temperature. At the same time, it is humidified by the exhaust air of the air-conditioned room.
The difference between total heat and sensible heat lies in the influence on humidity. If there is not much requirement for humidity, choose a sensible heat exchanger. Conversely, choose a total heat fresh air ventilator.
A total heat exchanger is an energy-saving device used for the energy recovery of air conditioner exhaust air. Its main components are the outer shell, the heat exchange core body, and the filter. Since the heat exchange core body uses materials with heat transfer and moisture permeation properties, when applied to an air conditioning system, it can use the exhaust air to precool and dry the fresh air in summer and preheat and humidify the fresh air in winter, significantly reducing the fresh air load, thereby saving the energy consumption of the heating and cooling systems. For small-scale systems, it is very beneficial for saving operating costs and reducing peak electricity consumption. Its total heat exchange efficiency is related to the structural characteristics of the heat exchange core body, the air volume passing through, the ratio of the air volumes of the two air flows passing through the core body, and the inlet air parameters.
Generally speaking, total heat exchangers are more commonly used in southern regions, while sensible heat exchangers are more commonly used in northern regions relatively.