Efficient heat exchanger air with his hands

Anyone who reads constantly Forumhouse, knows that good ventilation - the key to a healthy microclimate in the house. Properly designed and installed ventilation system It provides a constant flow of fresh air in and out the exhaust outflow. However, in winter, together with the exhausted air is discharged outwardly precious heat, and cool air from outside enters the building, which is spent on heating of the additional energy.

So as not to heat the street, an increasing number of modern and energy-efficient homes equipped with recuperators. And since Prices for industrial designs, to put it mildly, bite, the best way - is to roll up your sleeves and make such a device yourself!

What is an air heat exchanger?

Before proceeding to the design of the heat exchanger, it is necessary to understand the principle of its operation.

The word "recuperator" (from Latin «recuperatio») means obtaining or return anything back. Air heat exchanger - a device, wherein through heat exchange heat is transferred from the outgoing flow, already heated air, the incoming cold air.

We should not confuse air heating and recovery. If the first relates to the heating system, the heat exchanger is part of a modern system of a country house ventilation.

Effectiveness and economic benefits of installing a recovery system in the house depends on the following factors:

• energy costs;
• expected life of the system;
• amounts spent on the installation of the system;
• the amount spent on annual maintenance of the system.

Recuperator - is only part (and not the most expensive) mechanical ventilation system. Therefore, the heat exchanger and the ventilation should be regarded as a general system.

types of heat exchangers

Recuperators are classified depending upon the design and purpose, namely:

1. By type of coolant flow (air) - cocurrent or countercurrent.

2. In design and principle of operation of the heat exchanger:

• rotary heat exchanger

This type of heat exchanger is a closed housing with installed inside rotor (drum) driven by an electric motor.

The rotor is rotated at a certain speed and turns alternately in the zone of warm or cold airflow.

Thus, the rotor plate cyclically then heated then cooled.

As a result, the accumulated heat is transferred to the incoming cold outside air.

Recuperators rotary type have a high efficiency (up to 85%), not frosted at low temperatures and partially controlled humidity level.

Among the main disadvantages of the heat exchanger of the rotary type are:

• complex construction, consisting of an electric motor rotor, the drive belt and the duct system;
• increased noise level;
• presence of moving parts reduces the reliability of the system and leads to the need for more frequent maintenance.
• plate heat exchanger

The plate heat exchanger is a heat exchanger (drawer), consisting of a plurality of thin plates, connected to each other with a small gap.

Warm air passes through a cartridge heats the plate, which in turn - due to the rapid heat transfer, energy transfer to cold flow.

Because air flows are not mixed with each other, heat exchange is performed due to the simultaneous cooling and heating plates from all sides.

Among the advantages of plate heat exchanger can be identified:

• low cost;
• compact size;
• simplicity of the device;
• no moving parts.

In this type of heat exchanger at low temperature, due to condensation, frosting occurs exchanger plates.

Despite the significant disadvantage of this type of heat exchanger is the most common in self-designing.

Heat exchanger with his own hands

The heat exchanger plate heat exchanger is most often made of square plates. Vkachestve mother's plates are used:

• a thin copper or aluminum sheet;
• foil;
• vapor-permeable membrane.

In the manufacture of the plate heat exchanger important to maintain certain distance between the plates.

The smaller the gap between the plates, and they are thinner than, the greater the heat exchange between the air streams. RespectivelyIt increases plant efficiency.

However, reducing the thickness of the gap leads to increased condensation rate. This in turn causes plugging channels in a heat exchanger and causes the drop efficiency of the recuperator.

To combat this occurrence, further cold incoming air is preheated by electrical heaters or disable incoming inflow and purged only warm air heat exchanger.

This increases the complexity of manufacturing the heat exchanger at home.

However, the user of our site with the nickname Megavolt gathered efficient plate heat exchanger with a control unit. Validating plate first decided to do from a sheet of copper, but because of its high price, decided to go to a food aluminum.

megavolt:

- I was afraid that the heat exchanger of the foil starts to vibrate and "will sing", but I was wrong, the installation does not work louder computer. Glued plastic housing. Performance heat exchanger - 200 m3 per hour. I also made the processor system control unit. Now you can observe the work of the heat exchanger, so to speak, in the "online".

In the operation mode is displayed outlet temperature and inlet air, time, fan capacity. In the event of a power failure of the control unit power provided by the battery.

Besides the metal, polycarbonate can be used for manufacturing a heat exchanger. This is what Hecs73

Hecs73:

- I bought 11 sheets of honeycomb polypropylene 3m / 2m / 3mm. I sawed them into parallelograms 1h0.5 m and glued with silicone. The gap between sheets of supervised 3mm cord. Lace squeezed during assembly, and the gap left 1.5-2 mm, which is beneficial to the efficiency and adversely - by pressure drop. The heat exchanger is installed in a foam box, summed up the insulated ducts in the diameter of 160 mm and set the heat exchanger to the attic. Fitting Performance - 150 m3. Measurements have shown that at a temperature of 5 ° C outdoors and 24 ° C- in the building on the inflow turns 22 ° C.

Also include homemade widespread coaxial type heat exchangers.

Vitman:

- In my opinion, in the home easier to make coaxial (tube in tube) heat exchanger.

Such a recuperator is made of plastic sewer pipe diameter of 160 mm and a length of 2 m and aluminum air bellows 100 mm and a length of 4 m.

at the ends plastic pipe Dress-splitters adapters, and inside the tube, in a spiral corrugation fits fully stretched. Due splitters, warm stream chased through corrugation and cold flow goes inside the plastic tube. The resulting streams are separated and are not mixed with each other, and the cool air passing through the heat exchanger is heated.

sim1:

- As an experiment, I combined the coaxial heat exchanger with ground heat exchangers. plastic pipe length - 2.3 m, diameter - 160 mm. Aluminum corrugation: length 3.5 m, diameter 100 mm. Recuperator I have collected over 3 hours, and has managed it to me 5 t. Rub. Heat exchanger placed horizontally.

Validating the results of tests obtained the following data:

• The room temperature + 24 ° C.
• Inlet air temperature -7 ° C.
• Outlet air temperature + 19 ° C.
• Performance heat exchanger up to 270 m3.

Vitman:

- The longer the path that passes the cold air in the heat exchanger, the higher efficiency of the installation. I advise collect active recuperator of 4 pipes of 2-2.5 meters each. Further pipes better insulate. Condensate though it appears, but it will be much less than in a plate type heat exchanger, which will not work without additional heating of the incoming flow at low temperature. Condensate collection pipe can be set at an angle or vertically, and insert a nipple for draining.

Site users also FORUMHOUSEpredlagayut streamline design of the coaxial heat exchanger.

Master host:

- It is necessary to swap the supply and reverse flow and let the cold air of the corrugation.

Then, condensate will flow out of plastic and corrugated remain dry.

saks01:

- Because an outer pipe will still need to insulate, it is possible to completely give it up.

Answers to all the questions on the recovery and ventilation collected in this section. Here It describes the homemade heat exchanger with automatic. BUT here It demonstrates how to assemble the heat exchanger from polycarbonate. What happens when you combine a coaxial heat exchanger and ground heat exchanger - read in this topic.

And reading this Video clips you will learn how the heat exchanger helps to save heat.