Water heating do it yourself: everything about water heating systems
If a country house is actively used not only in the summer period, but also in the cold season, the creation of a high-quality heating system in it is an urgent need.
In heating systems, different heat carriers can be used: air heated to 60 ° C, water vapor at 130 ° C and water at a temperature of 95 ° C. Sometimes water can replace antifreeze. The topic of this article is water heating systems.
Classification of water heating systems
Depending on the location of the place of heat generation, water heating systems are divided into centralized and local.
In a centralized manner, heat supply, for example, apartment buildings, various institutions, enterprises and other objects. In this case, heat is generated in CHP (combined heat and power plants) or boiler houses, and then delivered to consumers through pipelines.
Local (autonomous) systems provide heat, for example, private houses. It is produced directly on the heat supply facilities themselves. For this purpose, furnaces or special units operating on electricity, natural gas, liquid or solid combustible materials are used.
Depending on the way in which the movement of water masses is ensured, the heating can be with forced (pumping) or natural (gravitational) movement of the coolant. Systems with forced circulation can be with ring circuits and with schemes of primary secondary rings.
In accordance with the direction of movement of water in the supply and return type highways, the heat supply may be with an associated and dead-end movement of the coolant.In the first case, the water moves in the highways in one direction, and in the second, in different directions.
Heating pipes can be connected to heating devices in different schemes. If the heaters are connected in series, this scheme is called one-pipe, if in parallel - a two-pipe. There is also a bifilar scheme in which all the first half of the devices are first connected in series, and then, to ensure the return flow of water, their second half.
The location of the pipes connecting the heating devices gave the name of the layout: they distinguish between its horizontal and vertical variety. By the method of assembly allocate collector, tee and mixed pipelines.
In those residential buildings where there are no basements, but there is an attic, heating systems with top wiring are used. In them the giving highway is located above heating devices. For buildings with a technical basement and a flat roof, heating is applied with a lower wiring, in which the water supply and drain lines are located below the heating devices.
There is also a layout with an “overturned” circulation of coolant. In this case, below the devices is the return pipe for heating.
Requirements for the operation of water heating
With all the diversity of water heating systems, a number of general requirements are imposed on their work.
They have to:
- warm all the air in the rooms evenly;
- be maintainable;
- do not create difficulties during operation;
- be linked to ventilation systems;
- to be regulated.
The very principle of the heating system itself is also common: water is heated,after which it circulates through the pipeline and gives away the resulting heat, warming the room.
Equipment power calculations
Indoor temperature depends on the following factors:
- on the air temperature outside the building;
- on the thickness of the walls of the house and the quality of its individual elements;
- from the ability of the materials from which the house is made, to retain heat.
When calculating the heat demand of your home, it is necessary to take into account all factors, including heat loss through windows and doors, walls and the ceiling floor. Special rules required in the calculation process should be applied taking into account the climatic conditions of the area in which the residential facility is located, and the degree of existing insulation.
The greatest heat loss occurs through the outer walls of the house.With the increase in the temperature difference inside the house and outside the building, heat loss also increases. If we take into account the material from which the outer walls were built, and the thickness of these walls, then for the external air temperature at - 30 ° C, the heat loss will be different and will be:
- Brick with internal plaster - 89 W / m² (2.5 bricks), 104 W / m² (2 bricks);
- Chopped with inner lining (250 mm) - 70 W / m²;
- From a bar with an internal covering - 89 W / m ² (180 mm), 101 W / m ² (100 mm);
- Frame with expanded clay inside (200 mm) - 71 W / m²;
- Foam concrete with internal plaster (200 mm) - 105 W / m².
However, heat loss occurs not only through the outer walls, but also through other enclosing structures. At the same - 30 ° C, they will be for:
- Attic wooden floors - 35 W / m²;
- Basement wooden floors - 26 W / m²;
- Double wooden doors without insulation - 234 W / m²;
- Windows with a double frame of wood - 135 W / m².
To calculate the total heat loss of a building, it is necessary to calculate the area of all enclosing structures in square meters, multiply by the standard heat loss by type of structure, taking into account the materials from which they are made, and sum up the results.
The calculation should be made based on the minimum seasonal temperature of a particular locality. Heat losses through the walls are calculated separately, since must take into account the area of glazing and doorways. Losses through overlaps without hatches in the attic or in the underground are calculated for the entire area as for single structural elements.
The heating boiler is chosen taking into account the fact that its capacity should be sufficient to compensate for heat losses with a 20-30 percent margin.
The procedure for calculating the thermal capacity of the equipment that will be used to install the heating system is given in the video clip in the final part of the article.
Water heating systems
With all the external differences and different wiring diagrams, the basic principle of operation of water heating systems is the same. The heat carrier heated in the boiler is transported through the pipeline to the heating devices. Cooling down, the water transfers heat to the environment, after which it returns to the place where it will heat up. This cycle repeats over and over.
Natural and forced circulation
In private homes use the following types of heating systems, which should be carefully considered:
- with natural circulation;
- with forced circulation.
Hot and cold water have different density - the principle of the natural circulation of water masses is based on this. The top positions of such a system are occupied by warm water, and the bottom positions are cold. Cooling down, warm water moves down, and when heated - up. The second factor that ensures the natural circulation of water masses is the slope under which the pipes are installed.
The advantage of natural circulation is its complete independence from the energy supply. She has more disadvantages:
- a small radius of action not exceeding 30 m in the horizontal dimension;
- long period of reaching working temperatures at all points of the system at start-up after a long break;
- the risk of stopping work due to the formation of ice in the open expansion tank.
The diameter of the pipeline must be large enough due to the low circulation pressure in the circuit. This factor also affects the choice of batteries, because modern radiators have a too narrow cross section, which creates additional resistance, which counteracts the circulation by "gravity".
In order to further stimulate the movement of the coolant, the pipeline is constructed with a slope so that an average of 3 mm per 1 running meter. Proper installation of pipes at the right angle is not an easy task, but without solving it, the system will function much slower and more efficiently.
To long-range radiators of gravity systems, coolant is leaking already substantially cooled. To maintain the temperature of heating, should use cast iron radiators. To balance the temperature difference, long-distance batteries must have more sections than those closest to the boiler.
Forced circulation provides the pump.In the scheme there can be one or several pumps. The use of several pumps is preferable: emergency shutdown of one of them will not damage the whole heating system. The coolant cyclically moves around a closed circuit, which includes an expansion tank, which eliminates the evaporation of water.
The benefits of forced circulation are:
- for installation of heating will need more pipes, but of smaller diameter;
- You can use different types of radiators and heat pipes with small diameters;
- the temperature of the heaters is easier to regulate;
- significantly increased the range due to the artificial stimulation of the coolant movement;
- the possibility of using heating units with enhanced characteristics of the coolant.
Negative enforcement systems depend on power supply. In order to avoid incidents with inactivity of heating,recommended to stock up on diesel or gasoline generator. In addition to the disadvantages include:
- the need for accurate calculation of the diameter of the pipeline, since Too narrow channels will dramatically increase the hydraulic resistance, and when circulating through too wide pipes, the coolant will “make noise”;
- considerable cost of construction due to almost double the length of the pipeline, the inclusion in the scheme of one or two circulation pumps, if necessary, booster pump;
- Mandatory use of expensive devices to control the flow of coolant, its temperature and pressure in the system.
The correct choice of the type of circulation depends on the individual characteristics and the location of the building in which water heating will be installed. However, schemes with a natural movement in recent years have become increasingly rare to resort to, using them mainly in buildings for temporary residence. Most often, private houses are equipped with systems for artificially forcing the coolant to move due to significantly greater possibilities.
Combined circulation systems
The combined system can function in both natural and forced mode. This means that during its installation it is necessary, as is the case with the use of natural circulation, to provide for a gradient of pipes of 3-5 mm per linear meter, as well as installation of a pump, as for forced circulation. Usually in such a heating scheme there is a solid fuel boiler.
The meaning of the combined system is that it will continue its work even in the event of a power outage. But the sudden cessation of heating in the winter period threatens not only lowering the temperature in the room.
The elements of the heating system can simply break down because the water, expanding when it freezes, will break their tightness.
Ways of installation of water heating systems
Consider the two main schemes of installation of heating systems.
Single pipe heating system
The single pipe version of the pipeline is characterized by a direct sequence of supplying the coolant to the radiators. The coolant fills and warms up first the first battery, then the next one, and so on. Two pipes are fed to each radiator from one pipe: the first is needed to supply coolant, and the second is used to discharge partially cooled water.
The peculiarity of this scheme is the relatively low heating of the last battery compared to the first one, since the water gets to it, having already given up some of its heat. Another disadvantage of the single-pipe version is that it is impossible to stop the flow of coolant to one particular radiator, in case of a breakdown. Have to shut down the entire system.
Two-pipe system and its variants
In the two-pipe heating scheme, as is already clear from the name, not one, but two pipes participate. In addition, each of the batteries is connected to one pipe in the line through which the coolant flows, and the second to the pipeline with return flow.It turns out that separate pipes are provided for the hot and cooled coolant.
Thanks to this heating design, the water in all radiators has almost the same temperature. The operation of such a system is easier to control, adjust and automate.
The two-pipe system, in turn, is divided into two types:
- with the upper laying of the supply pipe, i.e. with top wiring;
- with the lower laying of the supply pipeline, i.e. with the lower wiring.
Two-pipe systems with top wiring are constructed mainly in multi-storey buildings with attic space. Schemes with lower wiring in priority in private low-rise construction, because they allow to hide the pipeline laying to the maximum and eliminate or reduce the number of risers.
Comparative characteristics of one-pipe and two-pipe heating systems are given in the video material, which is located at the bottom of our article.
Open and closed heating systems
In addition to the types of water heating systems already considered by us, there is a division into an open and a closed structure.
An open heating system consists of a boiler (any other than electric one is used), pipelines, heating radiators, and an expansion tank into which excess water enters as it expands during heating. The tank is not sealed, water from the system can evaporate, so its level must be monitored and topped up if necessary.
The pump in the open design does not apply. The heating boiler is located at its lowest point, and the expansion tank - at its highest point.
Closed design sealed.It includes all the same elements as in the open. But since the movement of the coolant in it occurs forcibly, the mandatory list of elements is supplemented by a circulation pump.
Expansion tank, which is part of a closed structure, consists of two seamed parts, separated by a diaphragm. If an excess of expanded fluid in the system occurs, it enters one of the reservoir chambers, pushing the diaphragm into the second chamber filled with nitrogen or air.
When the coolant expands, the pressure in the system rises; a part of the tank filled with water tends to force out and compress the gas mixture. If the pressure limit in the tank is exceeded, a safety valve is activated, which discharges the excess heat carrier.
Each of the heating systems has its own advantages and disadvantages. They differ in a number of characteristics and are suitable for various objects.If you need to heat a small private house or cottage, use a simple and reliable open structure. Closed system, more difficult in installation and operation, is more often applied in solid cottages and in multi-storey buildings.
Elements of the heating system
Since we are going to install water heating in the house with our own hands, we need to have an idea about the components of the proposed design.
Determining the right boiler
The boiler is the heart of the heating system. It is very important to choose it correctly, since the reliability of heat supply largely depends on it.
Depending on the fuel used in the boiler, the following types of these devices are distinguished:
- Gas. This boiler is most popular with consumers. It is easy to install, works without too much noise. Gas is relatively inexpensive and produces a lot of heat when burned. But to use it, you need to get permission, order the installation of the supply line and organize exhaust ventilation in the boiler room.
- Electric. These boilers are the safest.The installation site does not need to be additionally equipped Their work does not produce an open flame and combustion products that could be poisoned. But the efficiency of this device is relatively small, electricity is expensive, and the energy-intensive boiler requires a reliable electrical network.
- Liquid fuel. Unlike gas, these boilers are equipped with a special kind of burners. This equipment requires a special boiler room. Liquid fuel quickly pollutes the boiler.
- Solid fuel. These devices burn coal briquettes and other solid fuels. If you are ready to harvest firewood or coal for the entire cold season, then you can use this option.
Combined boilers are considered the most reliable in which different types of fuel can be used. The disadvantage of such equipment is only one - such boilers are expensive.
What are the heating radiators
In order not to be disappointed as a result of the work performed, you need to take a responsible approach to the choice of radiators. At the same time, one should focus not only on aesthetic qualities, but on technical characteristics of batteries.And the technical properties are largely dependent on the material of manufacture of these products.
- Steel. These inexpensive products are too corrosive. If in summer, when heating is not used, water is drained from the system, the life of steel radiators can be significantly reduced.
- Aluminum. These attractive-looking radiators warm up quickly enough. Only significant pressure drops affect them negatively. In private homes, this danger does not threaten them.
- Bimetallic. Such batteries from aluminum got resistance to corrosion, and from steel - high heat transfer.
- Cast iron. These products are expensive, but they will last a very long time. They heat up for a long time, but then they cool for a long period of time. The heavy weight of cast iron products does not interfere with their operation, but may slow down the installation process.
There are new models of radiators, on the inner surface of which a protective coating is applied.These batteries are a bit more expensive, but the money spent on them pays off with interest.
How not to be mistaken with pipes
For installation of the heating system will require a lot of pipes. Which of them to give preference to:
- Metallic. The service life of such pipes is not too long. Over time, metal products can rust. They are mounted using threaded connections.
- Polymer. It is an inexpensive, but fairly reliable material, characterized by corrosion resistance. Even unprofessional can mount these pipes. The pipeline from polymer pipes will serve for a very long time.
- Metal-plastic. In the composition of these pipes aluminum and plastic. Pipeline of them collected on the threaded or press connections. As a side effect of the high thermal expansion coefficient of these pipes, they can crack with a sudden change in water temperature.
If the owners of the house have no restrictions in the means, it makes sense to arrange the wiring of heating from copper pipes.This is a very expensive material, but the cost of it is justified. Such pipes are reliable and durable. They tolerate high temperature and pressure. For their installation they use soldering - silver-containing high-temperature solder.
Everything that we told you above concerned radiator water. But water as a heat carrier can be used in other heating systems.
Water system "warm floor"
"Warm floor" can both successfully supplement radiator water heating, and become the only source of space heating, if we are talking about a low-rise building. The great advantage of the “Warm Home” is that this system provides conditions that fully meet the sanitary and hygienic standards of the room. The height of the room air is heated unevenly: at the top of the room it is colder, and at the bottom - warmer.
The temperature of the system is only 55 ° C, which corresponds to the design standards. The installation of pipes "Heat floor" is carried out over the entire floor area of each of the premises. This is quite a difficult job that can be qualitatively performed only at the stage of building a house. Operation "Warm Home" also causes a number of difficulties.
Plinth heating system
If the installation of the “Warm Home” is difficult, and the radiators spoil the interior of the room, you can use the plinth heating system.
With this type of heating installation of pipes is carried out by the baseboard, that is, just above the floor level. In this case, the room, as in the case of the "warm floor" is heated in the correct sequence.
At the same time, the floor is heated, which creates favorable conditions at any time of the year. Heating under the baseboard is becoming increasingly popular and is gradually coming into fashion.
Conclusions and useful video on the topic
Comparison of two-pipe and one-pipe heating systems:
The house you are going to live in all year round needs heating during the cold season.To make living conditions comfortable, you need to choose a water heating system that is most suitable for your individual conditions. We hope that the information contained in this article will help you make the right choice. After all, high-quality heating is not only comfort and coziness. It is also a prerequisite for maintaining your health.