The ability to organize an autonomous hot water system in a country house saves the owner from many problems when connecting to central communications. Moreover, often this is the only way to make hot water - for example, if we are talking about summer cottages or remote areas. But how to solve this problem with your own hands? Indirect heating boiler, coupled with the boiler, is the best solution to the problem without the help of specialists. The output should be an inexpensive, easy-to-use and at the same time productive system.
Equipment design
Despite the fulfillment of the crucial task of water supply, boiler plants have a fairly simple device. The basis is a container - a tank or other tank made of metal. At a minimum, you should rely on the preparation of a structure from a steel sheet capable of withstanding a physical pressure of up to 1 MPa. The tank must be sealed over the entire area except the lower and upper technological insets. As a rule, openings are provided with flanges and gaskets, which allow reliable fixing of pipe pipes for connecting the tank to cold water supply and the boiler. A heat exchanger is placed inside the tank, through which water will circulate. Before you consider the technique of making an indirect heating boiler with your own hands and the features of its connection, it will not be superfluous to familiarize yourself with its working process.
The principle of operation of the indirect heating boiler
In its finished form, the unit is connected to the central water supply line, which fills its main cavity and heat exchange network with cold water. On the other hand, the structure is connected to the heating equipment. Further work will be based on two main processes:
- Circulation of water flows through an internal heat exchanger.
- Heat transfer to the circulating medium from hot water in the tank.
Heated water is subsequently distributed through a previously created network and can be used both for heating and for household needs. The specific working scheme with intermediate functional stages will depend on how you plan to make your own indirect heating boiler. The installation technology of a simple configuration completely closes on the passage of water through the heat exchanger from the cold supply system to the water convector or batteries. In more complex versions, it is supposed to supply a hydraulic accumulator and a heat pump. These components make it possible, with minimal risks for the created infrastructure, to provide integrated hot water supply, raising the coolant even to the second floor.
Choosing a tank for a boiler
In choosing a storage tank, one should calculate its technical and physical characteristics, volume and shape. As for the first parameter, then, as already mentioned, it should be a solid steel tank, safe for use in households. It should not have defects, damages and protective chemical coatings. It is desirable that the inner surfaces are enameled. The volume, in turn, is calculated based on the planned water flow. The number of consuming plumbing, the number of people living in the house, the diameter of pipelines and other factors affecting the intensity of coolant consumption are estimated. On average, 50-60 liters should be planned per person. That is, a family of 4 people will need a capacity of 200 liters. The optimal shape for the tank is oblong cylindrical. In this design, the heat exchanger performs its function more efficiently.
The most affordable blank for a homemade tank with such characteristics is an unnecessary gas cylinder. This is a standard technology for creating a do-it-yourself indirect heating boiler, which involves preliminary cleaning of the tank. It is necessary to carry out degassing, and then clean the surfaces with special compounds and primed.
Heat exchanger device options
This is an important structural element, on which the reliability of the boiler, the productivity and the speed of heating the water depend. As already mentioned, cold water will circulate in the heat exchanger circuit, but its temperature should rise at the outlet of the tank. The following configurations of this component are practiced:
- Coil. The most common way to create a circulating channel in a storage tank. The coil is installed in the center of the tank and during operation passes through the coolant. The advantages of this solution include effective heating, but it will take a lot of time.
- Pipes. Conventional metal pipes are not installed in the center of the tank, but are attached to its walls. This is the simplest installation scheme for a heat exchange circuit for a do-it-yourself indirect heating boiler, since it does not require the manufacture of complex structures. Also, in terms of performance, this is the best option, but to achieve a high heating temperature it will take even more time than in a system with a coil.
- Design "tank in tank". It does not require the use of pipes and other circulation channels. A massive small tank is placed in the massive tank, which will periodically be filled with hot water. The system is simple and also quite efficient, but requires high power from the boiler unit.
How to make a coil?
For domestic use in terms of performance, the best solution would be a coil in the form of a coil. It can be made from a metal tube - brass or copper billets are suitable. The length and diameter are selected based on the dimensions of the indirect heating boiler itself. How to make a heat transfer coil with your own hands? The main task is to correctly perform the bends of the prepared metal tube. The easiest way to create a spiral involves wrapping a suitable diameter on a cylindrical structure (flat log or large-format pipe). The thickness of the heat exchanger should be 5-7 cm less than the inner diameter of the tank itself. Also, maintain small indents (3-4 cm) between the turns of the tube.
Basic installation operations
The main work will be related to the assembly process. Five holes must be made in the prepared tank: one at the bottom for the outlet pipe, two on the sides for connecting the heat exchanger, one on top for water intake, and one hole for draining from the bottom. At the points listed, stop valves with valves are attached. Next, do-it-yourself indirect heating boiler installation is carried out in the following order:
- The coil is installed in the center and fixed inside the tank to the walls by welding, and nozzles are attached to its outlet and inlet pipes.
- The heater is installed from the boiler.
- The boiler is closed by a lid.
- If necessary, you can prepare holes for instrumentation (for pressure, temperature, moisture and other indicators).
Installation and fastening of the structure
The boiler can be mounted in a hinged or floor position. In the first version, installation of a frame structure with holders in the wall is required. It is necessary to make anchor holes for fastening metal L-shaped profiles, after which a structure with hinge support should be seated on the damper plates. It is easier to install an indirect heating boiler on the floor with your own hands. For this, special metal supports are welded to the bottom of the structure. You can use a small supporting platform, but with a rigid fixation of the frame.
Equipment connection
First of all, it is necessary to connect the inlet to the central cold water supply. Here, control valves are mounted, thanks to which it will be possible to control the flow of circulating water. Next, to the indirect heating boiler with your own hands, you must connect the circuit from the heating unit. It will be connected with the coolant-coil in the input segment. The outlet pipe must be connected to consumer circuits. On this site, it is possible to provide a collector wiring, from which pipes to the kitchen will go, to water heating devices, points of intake in the bathroom, etc.
Unit Operation Tips
If you correctly combine the measuring instruments of the boiler with the automation of the boiler, then the user will practically not be required to participate in the management of the equipment. Particularly programmable panels are easy to use, as they can be configured for weeks of autonomous functioning. However, once every six months at least it is necessary to carry out maintenance with comprehensive diagnostics. Checking the technical condition involves revising the shutoff valves, assessing the tightness and diagnosing the system for operating indicators such as heating, pressure, temperature, etc. Regularly, manufacturers advise performing cleaning of the indirect heating boiler . With your own hands, using abrasive materials and plumbing chemistry, you should rid the inner surfaces of the tank and the coil from scale and all kinds of contaminants.
Advantages and disadvantages of a homemade boiler
Having a well in its own area, with the help of such equipment it is possible to provide a house with free hot water supply. In the future, this source can be used to organize the integrated distribution of heat in all rooms, and for other domestic needs. As for the shortcomings, it is quite problematic to make an energy-efficient indirect heating boiler with your own hands. The point is not even the complexity of installation and connection, but in the initial design of the piping of the circuits of circulation and distribution of water. In household home-made designs, there is often an irrational consumption of boiler resources for the delivery of hot streams and heating the contents of the tank.
Conclusion
Like any engineering equipment in the house, the boiler has high safety requirements. Actually, this is one of the reasons why many owners of suburban cottages still purchase proprietary installations for organizing hot water from the boiler. What should be taken into account in terms of protecting a home-made indirect heating boiler? With your own hands, it is desirable to make insulating shells for the structure, which can fulfill the function of heat saving and minimize the risks of mechanical damage. There are risks of water hammer. To prevent them, it will not be superfluous to connect a hydroaccumulator installation to the system, which will act as a water buffer with regulation of excess loads.