DIY recuperator: drawings, reversible recuperator

Many residents of city apartments had to make sure from their own experience that it is impossible to create a favorable microclimate in the apartment without good ventilation. It is wonderful when ventilation provides an influx of clean winter air into the apartment from the street, it is bad that in doing so we lose the same amount of heated air. In order to obtain fresh oxygen in abundance and at the same time prevent heat loss, it is necessary to use a recuperator. A huge selection of recovery systems is presented on the market, however, if you wish, you can easily make and install a recuperator with your own hands.

Efficiency and principle of operation of recovery systems

Recuperator in Latin - “returning” or “receiving back”. In our case, it plays the role of a heat exchanger, whose task is to retain thermal energy, which tends to leave the room with outgoing air in the cold season, and block the flow of the same thermal energy (in the form of hot air) into the room in summer period.

The air recuperator consists of several channels through which, without mixing with each other, air flows enter and leave the ventilated room. If the temperature of the air flows varies, they begin to exchange thermal energy, and, accordingly, hot air cools down, and cold air heats up. In addition, the process is air drained, this is due to condensation of the liquid on the channels of the heat exchanger. The use of recovery systems helps reduce heat loss by up to 70%.

Using a recuperator in the ventilation system allows you to:

• have constant high-quality heat transfer;
• compensate for the inefficiency of natural ventilation due to the installation of sealed windows and doors;
• refuse to use energy-intensive heaters and air conditioners;
• save on heating;
• maintain clean air in the apartment - there will be no street dust and pollen from plants.

The ventilation system with a recuperator allows for constant updating of indoor air and creates comfortable temperature conditions inside the room.

Types of recuperators

Recovery systems can be divided into several types.

• Direct-flow, counter-current, cross recuperators differ in the way they move air flows.
• Depending on the design features, recuperators can be ribbed, tubular, lamellar and lamellar-ribbed.
• According to the material of manufacture, the heat exchangers are metal, plastic, membrane.
• According to the principle of action, there are:
  • lamellar (cross-accurate) recuperator is the most popular type of simple design used in houses and apartments;
  • rotary recuperator - for operation, an electric power source, a rotary rotor element, is required, they are large and have high efficiency (up to 87%)
  • roof recuperator - installation of an industrial level;
  • coaxial recuperator - easy to perform even without experience;
  • recirculation (liquid) recuperator - transfers heat to the air using water or antifreeze, have a complex structure and efficiency comparable with the efficiency of a plate heat exchanger.

Plate recuperator

Lamellar recuperators are most often performed in the form of a tank, divided inside by strips of galvanized steel, which create channels for the movement of air flows. Moving through the channels, the air jets do not mix, but they can exchange thermal energy, which leads to equalization of the temperatures of the incoming and outgoing air flows.

Ventilation systems, which are based on plate heat exchangers, have several advantages:

• high efficiency - up to 65% efficiency;
• simple design and compact size;
• ease of manufacture and maintenance;
• ease of adjustment;
• the ability to install in any section of the duct;
• lack of need to use electric energy;
• lack of moving and rubbing parts.

Such heat exchangers have their drawbacks:

• The risk of freezing at low temperatures due to moisture condensation in the channels of the recuperator, which reduces the efficiency of the device.
• Inability to control air humidity.

To date, the use of plate-type recuperators in supply and exhaust ventilation systems is considered the most effective solution for an apartment.

Independent manufacture of a plate-type recuperator

Since the average cost of a plate heat exchanger is 300 oz. e., it makes sense to make this DIY recuperator easy to manufacture.

In order to make a recuperator yourself, you will need:

• galvanized metal sheets (4 sq. m.);
• technical stopper 2 mm thick;
• neutral reaction silicone sealant;
• tin box for the case or sheets of MDF, metal or plywood for its manufacture;
• glue;
• insulation 4 cm thick (mineral wool or polystyrene);
• corners for racks;
• plastic flanges;
• jigsaw or grinder.

Stages of work:

1. We cut the material into small squares with side sizes from 200 to 300 mm. The plates should be the same and perfectly even, it would be better to cut the sheets folded in a pack with a grinder than to use scissors for metal. About 70 pieces of such plates serving as blanks for recuperator cartridges should be obtained.
2. In order to create a gap between the sheets we use a technical cork. The bottom line is to make such a section at which the air flow rate will be 1 m / s. Glue the cut cork along the two opposite edges of the square blanks, without touching the last.
3. After waiting for the glue to dry, we create a heat exchanger cassette, gluing the sheets so that each subsequent one is at an angle of 90 degrees to the previous one. The cassette produces alternating channels perpendicular to each other. The last will be the sheet on which we did not glue the cork.
4. After connecting all the plates with a corner, we tighten the structure with a frame.
5. All cracks are carefully sealed with sealant.
6. On the walls of the cassette we have fasteners for flanges having a diameter corresponding to the duct pipes. It is advisable to place the cartridge vertically, then condensation will collect at the very bottom. A drainage channel is being prepared in the same place: an opening with a tube for draining the liquid.
7. In order for the cassette to be removed from the housing, it is necessary to install guides from the corner inside it.
8. The case with the cassette is placed in a box made of thick plywood or sheet metal. An important point will be the use of heat-insulating materials (mineral wool or polystyrene), which are glued to all sides of the box from the inside.

Note! The width of the recuperator case must correspond to the width of the cassette, the height and length - the diagonals of square plates.

For more reliable operation of the recovery system in conditions of negative supply air temperatures when the plates the heat exchanger can freeze, a bypass is added to the system, through which, if necessary, direct the supply air flow air. At this time, only warm exhaust air will pass through the heat exchanger, and under its influence, icy plates of the heat exchanger will thaw.

The efficiency of a self-made recuperator will be about 60–65%, which will ensure that the optimal microclimate is maintained in the room.