Heat recovery, what is it?
The term "recovery" of comes from the Latin word "recuperatio", which in translation means a return, the return receipt. In other words, it is the return of energy, which was spent on a particular process, for its re-use. In the climate technology this is the repeated use of heat, which is contained in the air( in the house) to heat incoming fresh air. Heating occurs in a special heat exchanger.
And to ensure that the fresh and outgoing air in the recuperator is not mixed, they are separated. If the room, on the contrary, needs to be cooled, then the cold recovery is done. That is, from the exhausted air is given cold to the supply. As can be seen from the above, this process has many advantages. The only drawback is the initial installation costs.
The recovery is best when the house has forced-air ventilation. Such a system is most effective, since it minimizes heat loss, and also provides good air exchange.
Types of recuperators( heat exchangers)
In order to give a description of the species, let us first understand what the recuperator is. In fact, it is a soundproofed metal case that has a heat exchanger and 2 fans( exhaust and supply).Exchange between the outgoing and outgoing flow is not through a direct contact, but just through the heat exchanger. It is he who is the main link of this design and can be of different types.
- Rotary has high efficiency( about 75-90%), it is used mainly in large buildings, industrial enterprises. Heat is transferred by means of the rotor between the exhaust and the supply channel.
- Plate, with an efficiency of about 50-80%, is used in small enterprises, cafes, houses. It has the appearance of a whole series of plates, on both sides of which there is a supply and exhaust air.
- The camera is a camera that is divided into two parts by a shutter. First, the removed air enters the one chamber and heats its walls. Further, the flap changes the flow direction so that the supply air is already heated from the walls. More often it is installed in homes, in cottages, its efficiency is 70-80%.
- With an intermediate coolant ( water-glycol solution or water) that circulates between 2 heat exchangers( one located in the supply air, the other - in the exhaust duct).It is installed in any premises. They have low efficiency( 45-60%).
- Heat pipes with an efficiency of about 50-70%.They look like a closed system of tubes, which are filled with freon. When the exhaust air is heated, it evaporates, and when the supply air enters, Freon again condenses into the liquid. Suitable for installation in industrial plants, used in the military and space industries.
Heat recovery system: components
Ventilation with heat recovery from the above heat exchangers uses two - rotor and plastic. It is important to remember that its main function is only to transfer heat from one stream to another. Plus, in this mechanism there are fans and filters. Fans contribute to the inflow and exhaust of air.
Recuperators are installed in the ventilation system of a country house in an air-casing casing. In apartments such heat exchangers are not needed, since the apartment is connected to a single ventilation system of the entire panel house.
They can have one single motor or two. As a rule, it has several modes. For example, when ventilation in a house with a large number of smoking guests is required, then the maximum mode is used. If there is no one in the house, or the owners are asleep, then - the minimum. The ventilation unit is also mounted and filters. This is necessary in order to clean the incoming air. In some recuperators, air is mixed. That is, the outgoing and already polluted stream is mixed with the incoming one. There are such processes in the presence of a chamber or rotary heat exchanger. Therefore, the filters are mounted on the path of the flow leaving the recuperator.
