To supply heat in residential and public buildings, heating registers made of smooth pipes are installed. These are devices that are designed to increase the efficiency of heat exchange between external environment and coolant.
The registers consist of several smooth-walled steel pipes connected by special pipes of smaller diameter. In their shape they resemble a zigzag or a “fence”. In this regard, there are sectional, coil, registers made of smooth pipes with columns, and registers with heating elements.
Features of heat exchangers
Section registers
Such devices consist of one or several pipes, which are closed with plugs. Through the pipe hot water enters the upper pipe, after which it flows into the next one, located one level below. According to this principle, water is distributed to all parts of the device.
The transition from one section to another is done as close to the edge as possible to ensure sufficient supply working environment and high heat transfer.
Such a heat exchanger is made from steel pipes with a diameter of 25 to 400 mm. Registers made of smooth pipes with diameters of 76 mm, 89 mm, 108 mm, 159 mm are widely used. The inlet and outlet pipes are made threaded, flanged or welded. Plugs – flat or elliptical. The kit for such a device includes a threaded fitting to which an air vent is connected. The heat exchanger can withstand a working pressure of 10 kgf/cm 2 or 1 MPa.
Coil heat exchangers
This type of heat exchanger is made from one solid pipe. Smooth tube s-shaped registers are efficient in their heat transfer, since the entire surface of the pipe gives off heat.
Coil heater shape
Another advantage is that this configuration does not provide for the presence of pipe narrowing areas. This feature prevents an increase in hydraulic resistance.
Traditionally, heating registers are made of smooth-walled steel, often carbon, although there are also homemade cast iron models, stainless steel or low-alloy steel pipes.
Pipes for register heat exchangers
Compactness and high efficiency registers allows them to be widely used in residential construction, office premises and those facilities that are characterized by increased sanitary and fire standards.
Registers with heater
Devices with heating elements are installed in those rooms where there are problems with laying communication lines.
Power heating element ranges from 1.6 to 6 kW at a voltage of 220 V. In operating condition, the heating element maintains the register surface temperature within 80˚C.
To increase the efficiency of heat exchange processes, the device is equipped with a circulation pump.
Working as an element of a central heating system, the heater reacts to decreases and increases in temperature. In accordance with this, it either compensates for heat loss or, on the contrary, turns off.
Such heat exchangers have many advantages:
- fire safety;
- easy accessibility during cleaning;
- big square heat transfer;
- economy;
- multifunctionality.
Manufacturing of heating registers
Preliminary calculations
To make a heat exchanger with your own hands, you need to calculate a register made of smooth pipes.
- Formula
The calculations are based on the following formula:
Q = Pi x dn x l x k x (tg - to)x(1 - ηiz),
wherein
Pi number – 3.14;
dн – outer diameter of the pipeline (in meters);
I – section length (in meters);
k – coefficient (equal to 11.63 W/m²*°С);
to – temperature in the room intended for installation of the device;
tr is the temperature of the working medium in the pipeline;
ηiz – coefficient of heat conservation by insulation (if the device is not insulated, this coefficient is equal to zero, if insulation exists, ηis = 0.6÷0.8).
The resulting result will show the thermal power for smooth pipe registers, which is applied to one horizontal pipe. If the device has several rows, a reduction factor of 0.9 is used for each additional row.
If you are having difficulty figuring out how to calculate a smooth pipe register, look for online calculators. As practice has shown, this method of solving the problem is not always accurate, so it is recommended to double-check the result obtained with a formula and only then begin manufacturing the device.
- Standards
Installation of registers is carried out according to GOST standards. To fix it, you will need a welding machine, since the fastening must withstand the weight of the working environment and the weight of the heat exchanger itself.
Characteristics
Operating principle of registers made of smooth pipes
Registers made of smooth pipes have the following specifications:
- do not require the use of highly professional equipment (use an angle grinder, electric welding);
- they heat large rooms with only a register of 2 or 4 smooth pipes;
- are made from available material(stainless steel, steel, cast iron);
- available for various working environments (work not only on water, but also on steam, oil and other liquids);
- multivariate in their shape, use of fittings, coating materials, plugs;
- in production it is possible to use drawings for reuse;
- available according to their own pricing policy.
A register made of smooth pipes in a living room
Not only radiators, but also factory and heating registers can be used as heating devices. self-made. Previously, such heating devices were most often installed in garages, warehouses, industrial workshops and other commercial facilities. In order to reduce the cost of installing autonomous heating systems, similar products began to be used in residential low-rise buildings. It’s worth noting right away that heating rooms using heating registers is less effective compared to batteries. The latter benefit due to the larger heat transfer area formed by additional plates that are absent in the registers of the basic design. If desired, the owner of the object can eliminate this disadvantage, welding vertically oriented metal plates. Otherwise, this problem can still be solved by increasing the number of welded pipes of smaller diameter. This modification of the design of heating registers is resorted to not only in order to increase the heat transfer of the device, but also to implement design ideas.
For the manufacture of heating registers, smooth-walled pipes of the same diameter and the same length are prepared. The diameter can range from 32 to 80 mm. Wider pipe products should not be used, because domestic boilers will not be able to provide the heating device with sufficient coolant. The registers will not be able to warm up well, which means they will not provide heat to the room in which they are installed.
By using gas welding or electric welding, these workpieces, located parallel to each other, are welded together with pipes of smaller diameter. Through these transverse tubes (pipes) the coolant flows, circulating in the heating system of the house.
Classic designs of heating registers
Option #1 - horizontal register
Most often, when manufacturing a heating register, two or three parallel pipes laid horizontally are connected. The distance between adjacent sections in the register must necessarily be 50 mm greater than the diameter. Coil designs of registers are also popular, divided into several types depending on the method of connecting devices to the heating system.
Heating registers of coil type: L - length heating device, D - pipe diameter, h - distance between pipes (50 mm larger than diameter)
The length of the heating devices is selected in accordance with the dimensions of the room or room in which it is planned to install the heating system. In addition to the listed types of heating register designs, there are also:
- single-pipe products;
- four-pipe devices;
- five-pipe models, etc.
The number of pipes used in one heating register depends on the area of the heated room, the quality of the object’s thermal insulation, the presence of other heat sources in the room, etc. By sorting through the possible pipe diameters, the optimal dimensions of the products are calculated, at which the optimal temperature regime will be maintained in the heated room.
Horizontal heating registers made of smooth pipes are used when bottom wiring pipeline. In this case, the products are carefully placed around the perimeter of the room closer to the floor surface. In a residential building, pipes go under the windows. IN production premises The location of heating devices depends on the height of the ceilings, the layout of the facility and the placement of industrial equipment.
Heating registers successfully heat social facilities. Caring for such heating devices is much easier than cast iron radiators.
Option #2 - vertical registers
When remodeling apartments and expanding their living space with balconies and loggias, it is necessary to dismantle the batteries installed by the developer when handing over the property. In this case, the dismantled radiators are replaced with vertical heating registers welded from a large number of round pipes of small diameter. These heating devices are placed in a wall located next to the window opening.
If necessary, vertical heating registers are covered with decorative grilles, which turn required element heating systems into an interior decor item. You can disguise the location of the “bundle” of parallel pipes using mirrors, colored glass, mosaics, forged gratings, as well as by placing shelves, hangers, cabinets and others useful items no bulky furniture.
It is possible to ensure the movement of coolant in a vertical register installed in an autonomous heating system of a private house using a circulation pump. Horizontal registers are also used for natural coolant circulation, if they are installed with slight slope(0.05% is enough).
How many registers are needed to heat a house?
Pipes supplying coolant to heating devices can, to some extent, also be considered registers. And the heated towel rail installed in every bathroom is also a kind of heating register. When calculating the exact number of heating registers required for comfortable heating of a room, a number of factors are taken into account that influence the amount of heat loss:
- thickness load-bearing walls and the material of their manufacture;
- glazing area;
- Number of doors;
- thermal insulation of floor and ceiling;
- orientation of the house to the cardinal points, etc.
A simplified calculation takes into account the heat transfer of one meter of pipe. For example, it has already been calculated that one linear meter A 60 mm diameter pipe is heated by one square meter living area of the room (provided that the ceiling height is no more than 3 m).
If you purchase ready-made heating registers instead of radiators, you will not be able to achieve significant cost savings. It is possible to reduce financial costs only if you independently manufacture register-type heating devices from materials purchased in bulk at discounts on the market. Welding work must also be done by hand. Otherwise, the cost of a professional welder’s services will cover all the benefits from the wholesale purchase of pipes and connecting elements.
Installation methods: welding or threading?
Most big problem when conducting installation work The assembly and installation of heating registers involves welding work. Heating appliances are assembled from individual parts outside the room, and then the heating system is installed from the prepared blanks using gas welding. Welded seams can be replaced with threaded connections, which are inferior in strength and durability, but subject to the technology of work and use modern materials can ensure long-term operation of heating equipment.
The heating register in a garage or warehouse is independent device allowing to heat the room technical purpose using electricity
Homemade registers from round pipes
On the market you can purchase homemade heating registers sold by professional welders. If the finished products do not fit your size, then welding experts will make heating devices according to individual order. Quality homemade products is not questioned, therefore they are built into autonomous systems heating.
“Samovars” with heating elements are also popular among consumers. This is the name for heating registers that heat themselves separate rooms due to electricity. Instead of water, oil, antifreeze or any other non-freezing liquid is poured into the pipes. Heating of the coolant is carried out by a conventional heating element operating from a network with a voltage of 220 V. “Samovars” in their design resemble oil radiators, produced in factories. “Samovars” are used in extensions where it is impossible or impractical to construct a water heating system. Heating devices operate in autonomous mode, and their performance depends only on the availability of electricity.
A samovar is one of the types of heating registers that are not connected to the home heating system, but heat one of the rooms using electricity
Homemade register from a profile pipe
To make a heating register from a profile pipe, choose a product with your own hands rectangular section(60 by 80 mm), the wall thickness of which is 3 mm. Homemade battery heating (register) is assembled in several stages:
- first, cut the pipe into several pieces of a certain length;
- then markings are made on the blanks for the holes into which the jumpers will be welded;
- make four jumpers from inch round pipe(25 mm);
- plugs are cut from a 3-mm sheet of metal, the size of which is determined by the rectangular section of the profile;
- cut out holes for jumpers in the places where the markings were applied, while the upper and lower pipes of the register should have two holes on one side, and the middle pipe should have four holes (two on both sides of the part);
- on wooden stands(beam) lay out three pipes parallel to each other;
- jumpers are inserted into the holes in the pipes, the parts are leveled and each jumper pipe is electrically welded in three places;
- then the product is turned from a horizontal position to a vertical position;
- begin to weld all stuck jumpers into two seams, adjusting the welding current to prevent the formation of possible leaks;
- after profile pipes cleaned of slag and metal debris that has fallen inside the cavity of the product;
- previously prepared plugs are applied to the ends of the profile pipes, grabbed diagonally, and then thoroughly welded along the entire perimeter of the rectangular section of the profile;
- use a grinder to lightly grind the weld seams along the entire heating register;
- a hole is cut out in the upper pipe of the homemade register for Mayevsky’s tap;
- connecting the register to the heating system can be done from the bottom, side, top or by a combination of the listed options (bottom and top, diagonally, etc.):
- the exit hole is closed with a plug, the register is filled with water, after which the master inspects all welded joints, eliminating the possibility of leakage through microcracks;
- weld floor supports from steel corners or brackets that allow you to mount the device on the wall.
Such a register has high heat transfer due to the large amount of coolant flowing through profile pipes. The jumpers should be located as close as possible to the end edges of the horizontal parts. The coolant is supplied through the inlet pipe located in the upper pipe. After passing through all the elements of the device, the coolant flows out through the outlet pipe located on the lower pipe.
A heating register of four parallel pipes connected by side riser pipes heats the living space
As you can see, making a heating register with your own hands is not at all difficult if you have welding machine and experience working with it. Homemade heating devices can be welded to exactly match the dimensions of the heated room. To purchase a ready-made heating register, you will have to prepare three times more money than to purchase all necessary materials for self-welding of the product. To provide long work device, purchase pipes made of carbon steel, low-alloy stainless steel or cast iron.
Everyone knows that heat transfer (heat transfer) - the transfer of thermal energy - between bodies and media occurs when there is a temperature difference. Environment or body having more high temperature, cooling, heats the colder environment and increases its temperature.
In water heating systems, hot water (coolant), entering the heating device, heats its walls (shell). The walls, through their outer surfaces, give off heat to the air mainly in two ways: convection and radiation.
Convection is the transfer of heat to air currents flowing along the hot walls of a heating device.
Thermal radiation is the transfer of thermal energy due to radiation electromagnetic waves hot walls of the heating device into the surrounding space.
A clear example of action thermal radiation is a fire. If on a cool evening you stand sideways to the smoldering coals of a fire at a distance of three to four meters, then the part of your face facing the fire will quickly heat up, while the opposite part of your face will remain cold. In this case, the air temperature on both sides will be approximately the same.
All devices - cast iron batteries, heating registers made of pipes, steel and aluminum panels, convectors and infrared emitters - differ from each other (except for dimensions, appearance, heat transfer coefficients) in the predominant type of heat transfer to the surrounding air and objects. In this case, as a rule, both convection and radiation exist simultaneously and act in parallel.
This article will consider an example of calculating the heat transfer of heating registers from pipes. It has never been economically profitable to make heating registers from smooth pipes - neither today nor yesterday. If 30-50 years ago they were widely used due to a shortage of high-quality, cheap and efficient heating devices, then the use of registers today is rather an inertial habit of heating engineers. The cost of a heating system using, for example, convectors is 20-30% lower than the cost of a system using pipe heating registers. The heat transfer of devices should be maximum at minimum cost and, accordingly, minimum material consumption and labor intensity of manufacturing. However, these are often mutually exclusive criteria.
However, the issue of heat transfer from steel pipes remains relevant if they are used for wiring, as well as when performing comparative calculations various options systems and during repairs existing systems, in which heating registers made of smooth pipes are used.
Based on theory and practical experiments on heat transfer, as well as on the basis of numerous tabular data using Excel, I was able to find fairly accurate formula dependences of the thermophysical characteristics of air (thermal diffusivity, thermal conductivity, kinematic viscosity, Prandtl criterion) on temperature. Below is program for calculating the heat transfer of heating registers fromhorizontal metal pipes with free air movement, which is the result of the work done.
The calculation program is written in MS Excel, but you can also use the OOo Calc program from the Open Office package.
The rules for formatting Excel sheet cells, which are used in the articles of this blog, are presented on the page « ».
Heat transfer from heating registers made of smooth pipes. Calculation in Excel.
A heating register of four smooth pipes and a flow diagram of the coolant are shown in the figure below.
We turn on the computer, MS Office and start the calculation in Excel.
Initial data:
There is not a lot of initial data, they are clear and simple.
1. Pipe diameter D enter in mm
to cell D3: 108,0
2. Register length (one pipe) L in m we write
to cell D4: 1,250
3. Number of pipes in the register N we write in pieces
to cell D5: 4
4. Supply water temperature tP in °C we enter
to cell D6: 85
5. Return water temperature tO in °C we write
to cell D7: 60
6. Room air temperature tV in °C enter
to cell D8: 18
7. Select the type of outer surface of the pipes from the drop-down list
in merged cells C9D9E9: "In theoretical calculation"
8. Stefan-Boltzmann constant C 0 in W/(m 2 *K 4) we enter
to cell D10: 0,00000005669
9. Acceleration value free fall g in m/s 2 we enter
to cell D11: 9,80665
By changing the initial data, you can simulate any “temperature situation” for any standard size of the heating register!
The heat transfer of just a single horizontal pipe can also be easily calculated using this program! To do this, it is enough to indicate the number of pipes in the heating register equal to one ( N =1).
Calculation results:
10. Blackness degree of radiating surfaces of pipes ε automatically determined by the selected type of external surface
In the database, located on the same sheet with the calculation program, 27 types of external surfaces of pipes and their degree of emissivity are presented for selection. (See the download file at the end of the article.)
11. Average pipe wall temperature tst in °C we calculate
in cell D14: =(D6+D7)/2 =72,5
tst =(tP + tO )/2
12. Temperature difference dt in °C we calculate
in cell D15: =D14-D8 =54,5
dt = tst — tV
13. Air volumetric expansion coefficient β in 1/K we define
in cell D16: =1/(D8+273) =0,003436
β =1/(tV + 273)
14. Kinematic viscosity of air ν in m 2 /s we calculate
in cell D17: =0.0000000001192*D8^2+0.000000086895*D8+0.000013306 =0,00001491
ν = 0,0000000001192* tV 2 +0,000000086895* tV +0,000013306
15. Prandtl criterion Pr define
in cell D18: =0.00000073*D8^2-0.00028085*D8+0.70934 =0,7045
Pr = 0,00000073* tV 2 -0,00028085* tV +0,70934
16 . Air thermal conductivity coefficient λ we count
in cell D19: =-0.000000022042*D8^2+0.0000793717*D8+0.0243834 =0,02580
λ =-0,000000022042* tV 2 +0,0000793717* tV +0,0243834
17. Area of heat-transfer surfaces of register pipes A in m 2 we define
in cell D20: =PI()*D3/1000*D4*D5 =1,6965
A = π *(D /1000)* L * N
18. Radiation heat flux from the surfaces of heating register pipes QAnd in W we calculate
in cell D21: =D10*D13*D20*((D14+273)^4- (D8+273)^4)*0.93^(D5-1) =444
QAnd = C 0 *ε *A * ((tst +273) 4 — (tV +273) 4)*0.93 (N -1)
19. Radiation heat transfer coefficient α And in W/(m 2 *K) we calculate
in cell D22: =D21/(D15*D20) =4,8
α And = QAnd /(dt * A )
20. Grashof criterion Gr calculate
in cell D23: =D11*D16*(D3/1000)^3*D15/D17^2 =10410000
Gr = g * β *(D /1000) 3 * dt /ν 2
21. Nusselt criterion Nu we find
in cell D24: =0.5*(D23*D18)^0.25 =26,0194
Nu =0,5*(Gr * Pr ) 0,25
22. Convective component of heat flow QTo in W we calculate
in cell D25: =D26*D20*D15 =462
QTo = α To * A * dt
23. And the heat transfer coefficient during convection α To in W/(m 2 *K) we determine accordingly
in cell D26: =D24*D19/(D3/1000)*0.93^(D5-1) =5,0
α To = Nu * λ /(D /1000) *0,93 (N -1)
24. Total heat flow power of the heating register Q in W and Kcal/hour we calculate accordingly
in cell D27: =D21+D25 =906
Q = QAnd + QTo
and in cell D28: =D27*0.85985 =779
Q’ = Q *0,85985
25. Heat transfer coefficient from heating register surfaces to air α in W/(m2*K) and Kcal/(hour*m2*K) we find, respectively
in cell D29: =D22+D26 =9,8
α = α And + α To
and in cell D30: =D29*0.85985 =8,4
α ’ = α *0,85985
This completes the calculation in Excel. Heat transfer from the heating register from the pipes has been found!
The calculations have been repeatedly confirmed by practice!
A number of other articles are devoted to thermal calculations on this site. You can quickly access them using the links located below the article or through the “All Blog Articles” page. These articles explain the basic concepts of heating engineering simply and clearly with examples.
Notes.
1. It would be more correct to use in calculations not heat transfer coefficient α between the outer walls of the register and the air, and heat transfer coefficient k, taking into account the heat exchange between the coolant (water) and the internal walls of the heating register pipes, as well as the transfer of heat through the wall material (thermal resistance of the wall). The heat transfer coefficient from water to room air is calculated using the formula:
k =1/(1/ α 1 + sst / λ st + 1/ α )
But since:
α 1 ≈2000…3000 W/(m 2 *K) – heat transfer coefficient between water and the inner steel wall
sst ≈0,002…0,005 m – pipe wall thickness
λ st ≈50…60 W/(m*K) – thermal conductivity coefficient of the pipe wall material
1/ α 1 ≈0
sst / λ st ≈0
And therefore:
k ≈ α
2. The heat transfer of heating registers depends on the method of supplying water to them (from top to bottom, from bottom to top...), from the installation distances to the enclosing structures (to the floor, to the window sill, to the wall, to the screen), on the thickness paint coating and other factors. The actual heat transfer may be 15...20% less than the calculated one. This must be taken into account when making final calculations!
3. The distance between pipes and the number of pipes also influence the heat transfer of heating registers. The program partially takes into account the use of a reduction factor (0.93) for each additional row of pipes. It is advisable to maintain the distance between pipes at least as large as the diameter of the pipe D(more is better).
4. Heat transfer coefficient k is not a constant value for a specific heating device and changes significantly with changes in temperature pressure dt! Read more about this (and more) in upcoming blog articles.
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To organize heat supply for large rooms, it is not advisable to use standard factory batteries and radiators. They have too low thermal output and rated power. As an alternative, you can consider heating registers: production from pipes, calculation rules and installation features.
Advantages and disadvantages of heating registers
Homemade steel or aluminum heating registers differ from standard radiators in their size. They consist of several pipes whose diameter exceeds 32 mm. To organize the circulation of the coolant, the pipes are connected to each other by pipes.
What is the reason for the popularity of these heat supply devices? Firstly, the possibility of self-production. You can make bimetallic heating registers, steel or from aluminum pipes. Plastic models are much less common, as they do not have the proper performance qualities.
Before connecting heating registers, you should carefully study their “weak” and “strong” sides.
Benefits of use:
- Long service life. For steel and aluminum models it can reach 25 years. In this case, the probability of breakdown will be minimal;
- Great heat dissipation. This is due to the fact that the power of the heating register exceeds this parameter for classic radiators and batteries. Associated with a large volume of coolant;
- Easy installation and operation. Since anyone who is at least a little familiar with the rules for organizing heat supply can install heating registers correctly, they can be used in buildings of all types. But most often they can be found in the heating system of large industrial, administrative and commercial premises.
But besides this you need to take into account possible disadvantages that a heating register made of smooth steel pipe may have:
- Large volume of coolant. This leads to its rapid cooling;
- Minimum air convection rate. Reduces the efficiency of heat supply;
- Unattractive appearance. Most often this applies to homemade structures.
Correctly calculated heat transfer of a heating register directly depends on its design. Currently, several types of these heat supply devices are used, differing not only in the material used, but also in appearance.
The weight of the register filled with water can be very high. Therefore, you need to think in advance about a reliable system for attaching it to the wall.
Initially, you should decide on the type of structure. After all, how to calculate a heating register if its geometric parameters and the principle of coolant circulation are not known? For the manufacture of heating devices, it is recommended to use standard proven circuits.
The determining parameter of choice is the required circulation rate of the coolant in the system and the degree of heat transfer of the register. Based on these requirements, you can choose two types of heating devices:
- Sectional. It consists of two or more large-diameter pipes connected by pipes. The cross-section of the latter must be equal to the same parameter of the supply line. The selection of a heating register of this type is relevant for systems with forced circulation, since the design creates excessive hydraulic resistance during the passage of the coolant;
- Coil. They consist of one pipe that has bends. Making such homemade heating registers is problematic. To increase the circulation rate, pipes can be connected by pipes. But this is not mandatory, as in the models described above.
Since you can make a heating register with your own hands even at home, they are often made rather than purchased ready-made models. But before this, you must correctly calculate the power of the heating register.
To make registers, you can use pipes of various sections - round, rectangular or square. Preference is given to the first, since for them the friction of water during movement will be minimal.
Calculation of heating registers
There are several methods for calculating the parameters of heating registers. They are distinguished by calculation accuracy and labor intensity. But to organize heat supply using steel or aluminum heating registers, it is recommended to resort to the services of professionals. Alternative option– use special software.
However, in some cases it is necessary to correctly calculate the heating register yourself. To do this, you can use a simplified diagram. You must first know the following parameters:
- The total area of the heated room;
- Heat transfer coefficient of register material;
- Diameter of pipes used for manufacturing.
For round pipes, the specific power of the heating register can be calculated using the data in the table. These values are given for 1 lm. register pipes.
However, this method of selecting a heating register has a number of significant disadvantages. The data is given for rooms where the ceiling height does not exceed 3 m. The thermal operating conditions of the system and the air temperature in the room are not taken into account.
Q=P*D*L*K*Δt
Where Q– specific thermal power, W, P- number π – 3.14, D – pipe diameter, m., L– length of one section, m, TO- coefficient of thermal conductivity. For metal, this figure is 11.63 W/m²*C, Δt– temperature difference between the coolant and the air in the room.
Knowing these parameters, you can independently calculate the power of the heating register. Let's assume that the length of one section is 2 m, and the diameter of the pipe is 76 mm. Δt is 60°C (80-20). In this case, the power of one section of the heating register made of a smooth steel pipe will be equal to:
Q=3.14*0.076*2*11.63*60=333 W
To calculate each subsequent section of the device, the obtained result must be multiplied by a reduction factor of 0.9.
This method cannot be used to calculate finned heating registers. Their heat transfer will be higher due to the increased area of the device.
Selecting material for registers
The next parameter that must be taken into account when choosing a register is the material of its manufacture.
It is rare to see heating registers made from a profile pipe - most often steel products with a round cross-section are used for this.
Currently, several materials are used to produce registers - metal, aluminum or bimetallic pipes.
The difference between them lies in the calculated heat transfer and service life:
- Steel heating registers made of profile pipe or round section. They are characterized by ease of manufacture and low cost. Disadvantage: surface rusting. When choosing Special attention you need to pay attention to the quality of the welds;
- Aluminum. They are extremely rare, since welding aluminum heating registers requires special equipment. But they have better thermal conductivity. There is virtually no heat loss;
- Bimetallic. They are made from a special type heating pipes. They have a core made of steel. To increase the heating area, the design has copper or aluminum plate heat exchangers. All bimetallic heating registers are characterized by a small pipe diameter - up to 50 mm. Therefore, they are more often used to organize heat supply in residential buildings and small industrial and retail premises.
The material of manufacture directly affects the calculation of the heating register. The main indicator is the thermal conductivity coefficient. Although aluminum models have optimal value– their high cost and labor-intensive manufacturing do not allow the use of registers of this type in heating systems everywhere.
To manufacture ribbed heating registers, you can use components from steel radiators.
Making heating registers with your own hands
One of the advantages of using registers in heating systems is the possibility of making them yourself. For this, round steel pipes are most often used. Despite the fact that the heat transfer rate of the heating register in this case will not be ideal, the manufacturing process will not require special skills.
For self-production this heating element you will need a pipe with a diameter of 40 to 70 mm. A larger cross-section will lead to significant heat losses during coolant circulation. You can make a heating register with your own hands according to the following work plan:
- Calculation of the optimal parameters of the heating device - pipe diameter, total length of the section.
- Drawing up a drawing to calculate the optimal amount of material.
- Carrying out work on making a heating register with your own hands.
- Checking the structure for leaks.
To complete this task, you will need a steel pipe designed to form the main registers and a line of smaller diameter. With its help, the registers will be connected to each other and the heating system. You will also need special end caps for the pipes.
At the first stage, you need to use a grinder to cut the pipes to the required length. It is not recommended to use a welding machine for this, since a weld will form at the ends of the heating register from the round pipe. Then holes are made to connect the pipes. The pipes are welded using a welding machine and the end caps are installed. To ensure the safe operation of a homemade heating register, it is necessary to install an air vent and a drain valve. They are mounted in the upper part of the structure, but on the opposite side relative to the point of connection to the heating.
In some cases, upgrading is carried out traditional scheme steel or bimetallic heating register. It consists of installing an electric heating element.
This way you can make an autonomous heat source that will not depend on the operation of water heating. In the event of an accident or technical work a homemade heating register will generate heat using a heating element. But for this, shut-off valves must be installed during installation so that the coolant circulates only inside the heating device.
When choosing a design and making a heating register, the thickness of the pipe does not matter. The difference in diameters between it and the supply line determines the complete absence of water hammer in the structure.
Installation of registers in the heating system
Correct installation of heating registers can be done in two ways - using threaded connections or using a welding machine. It all depends on the total mass of the structure, its dimensions and the parameters of the heating system.
In general, experts recommend following the same rules as when installing radiators. The difference is only in the size of the structure. If it is necessary to connect the heating register to the gravity system, the required slope must be observed. The heat supply device must be tilted towards the movement of the coolant. There are no such requirements for systems with natural circulation.
For correct installation heating registers must be guided by the following rules:
- Maintaining minimum distances from the wall and window designs. It must be at least 20 cm. This is necessary for carrying out technical or repair activities;
- For threaded connections of the heating register, only paranitic linings or plumbing linen are used;
- All heating registers made of profile or steel pipes must be painted. This is necessary to prevent rust from appearing on their surface.
Despite the fact that the heat transfer rate of the heating register will decrease, the maintenance-free service life of the structure will increase significantly.
Installation is recommended to be carried out outside the heating season. After a trial run of the heating system, you can compare the calculated power of the register with the actual power and, if necessary, make operational changes to the design.
Operating rules for heating registers
To increase service life, it is necessary to carry out a number of measures to maintain heating registers in working condition. It is recommended that a control check schedule be developed that includes visual inspection and analysis temperature regime register operation.
In addition, periodic cleaning should be carried out inner surface structures against scale and rust. For this, it is best to use the hydrodynamic method, since chemical cleaning will require a large amount of special liquid. This can be done without dismantling the structure - it is enough to install pipes during manufacturing to provide access to the internal cavity of the register.
Every time before a new one heating season the integrity of the structure, the reliability of welded and threaded connections. If necessary, the gaskets are replaced and repair seams are welded.
Is it possible to use heating registers to supply heat to a private home? This practice exists, but for this purpose they order products from copper pipes. They are characterized by high cost, but at the same time they have a number of distinctive qualities. Their attractive appearance is also taken into account, which differs significantly from steel structures.
The video shows an example of making a register from a steel profile pipe:
Heating systems may include so-called registers - devices whose design assumes the presence of smooth horizontal pipes, parallel to each other. They have not gained popularity among the owners of private houses, which is quite objective reasons. Heating systems built using this type of registers consume significant volumes of coolant, which forces them to spend more energy on heating compared to standard radiators.
For the most part, registers are used in various industries. Serious dimensions and noticeable coolant consumption - all this is suitable for heating workshops, warehouses and other premises with a large area.
Heating registers – optimal efficiency provided they are used in industrial buildings. Conventional radiators are inferior to such heating devices, since they have better heat transfer and hydraulics. At the same time, the cost of their production is relatively low and they are cheap to operate, which makes it possible to organize heating systems that are economically beneficial.
Registers of this type are recommended to be installed in premises that are subject to strict sanitary safety standards, for example, these include kindergartens. Such devices are easy to maintain clean, as they can be cleaned from various types of contaminants without significant effort.
At the same time, heating registers cannot be considered economical. This is due to the consumption of significant volumes of coolant to maintain their functionality, which forces them to waste a lot of energy.
Application based on steel pipes is possible in heating systems characterized as single-pipe or two-pipe, regardless of the type of coolant circulation: forced or gravity.
Specifications
- The operating pressure is 10 atmospheres.
- Heat dissipation – from 500 to 600 W/meter.
- Possibility of using coolant in the form of water or steam.
- Connection by welding or threading.
Types of heating registers
There are 3 types of registers considered:
- Sectional in the form of the letter “P”.
- Serpentine, the shape of which is S-shaped.
- Mixed.
Pipes made of steel or stainless steel are used for production, the diameter of which ranges from 25 to 200 mm. Industrial premises with administrative or economic purposes are heated through the use of pipes with a diameter of 25 to 100 mm. As for registers with a larger diameter, reaching 200 mm, they are installed in production workshops and at sports facilities of varying scale, for example, swimming pools.
As applied to private households, their installation significantly reduces heating efficiency. 
When assembling registers, almost any number of sections can be used, which is determined only by the area of the room and the required amount of heat transfer.
When connecting sectional registers, jumpers are used that have a smaller diameter compared to the pipes that are part of the type of device under consideration. To calculate the optimal distance between heating pipes, use the formula D+50 mm, where D should be understood as the pipe diameter. Compliance with the distance calculated in this way makes it possible to minimize the infrared radiation of the pipes in relation to each other, which ensures an increase in heat transfer.
The connection of coils is possible due to bends, the diameter of which is identical to the diameter of the pipes. They are installed at the ends of the connected device. Because of this connection method, the cost of connecting registers increases, but not significantly. IN in this case increased costs are offset by increased operating efficiency, which provides a larger area work surface. Also, the coil register has such a positive aspect as lower hydraulic resistance compared to that present in the sectional version of such a heating device. This allows you to use circulation pumps, characterized by lower power and lower price.
End caps installed on pipes come in a variety of shapes: flat, round and elliptical. Plugs having an elliptical shape are used in systems where the coolant is supplied under high pressure. They are also used to give heating appliances a certain attractiveness. If there is a need, it is possible to equip the upper segment of the register with a fitting designed to install a degassing valve.
The variability in the design of heating registers does not end there; for example, there are devices of this type that are complemented by a heating element. The result is a device that does not require connection to the heating system, since the heating medium is heated by a built-in electrical appliance in the form of a heating element.
In the process of designing such devices, the power of heating elements is calculated in a certain way, which depends on how large the surface area of the device is. If the register overheats, this will lead to excessive activity of the expansion process and the coolant will flow out through the emergency valve. Otherwise, that is, if there is insufficient power, the efficiency of the heating element will be reduced to a minimum.
The autonomous register must be equipped with a fitting installed in the upper segment of this heating device. It is used to fill the coolant before putting it into operation and to install an emergency valve, which can be supplemented with an expansion tank, due to the need to compensate for the expansion of the coolant.
How to calculate the required number of register sections
The cross-section of register pipes is a parameter that affects the heating efficiency of a particular room. The more, the higher the heating result. Mostly, coil and sectional registers are used, consisting of 2–4 sections. This optimal size, and the product itself is light in weight, which is important in terms of installation.
Sections should be spaced 50 mm apart from each other plus the diameter of the pipe. Compliance with this rule eliminates the fact of mutual heating of the sections, thereby increasing heat transfer.
For calculation required quantity sections of registers, it is enough to refer to SNiP, which describes the correspondence of 1 meter of pipe of one diameter or another to heating a specific area:
- 25 mm – 0.15 m2;
- 75 mm – 0.37 m2;
- 160 mm - 0.77 m 2.
The given relations are correct only for the section at the entrance to the register. Due to the cooling of the coolant as it moves through the device, the calculation of subsequent sections assumes an increase in the area value by 0.9.
To make it easier to understand the required number of sections, you can use online calculators, of which there are many on the Internet. But you should keep in mind that not all work correctly, so you must first test them using the formula given above.
Q=P*D*L*K*Δt, Where
Q– specific thermal power, W,
P– number π = 3.14,
D– pipe diameter, m,
L– length of one section, m,
TO– metal thermal conductivity coefficient 11.63 W/m²*C,
Δt– temperature difference between the coolant and the air in the room.
This expression in the given form is also true only for the first section of the register or the first turn of the coil. For subsequent sections it must be multiplied by a factor of 0.9.
Before you start making registers, you should take care of purchasing the appropriate materials. You will need pipes of one diameter or another and some length. Exact numbers are not given here, since the type of device in question can be assembled from any pipes without focusing on their diameter and thickness. More important is to ensure optimal heat transfer, which involves carrying out calculations regarding the required surface area of the register.
To do this, you will need to determine the outer area of the entire system. The resulting value is then multiplied by 330 W. The use of this method is based on the statement that 1 m2 gives off 330 W of heat if the temperature of the medium is 60 °C and the air inside the heated room is 18 °C.
Advice! You don’t have to do manual calculations, but use a simple program in EXCEL and then correctly weld the register according to the exact parameters. You can download the program in one click from the link: http://al-vo.ru/wp-content/uploads/2014/02/teplootdacha-registra-otopleniya.xls.
For people skilled in welding, assembling the structure will not be difficult. It will be necessary to prepare pipes and cut them into sections, and also take care of plugs, for the manufacture of which you will need steel sheet. Register assembly does not presuppose the presence of given order actions. At the end welding work it is necessary to ensure the tightness of the created structure. Otherwise, the following advice can be given:
- pipes should be selected with optimal thickness walls, since too thin walls cool down quickly enough, and thick ones take a long time to warm up;
- the upper section must be supplemented with a Mayevsky valve, with the help of which air is released;
- assembly of the register in the form of a coil involves the use of a pipe bender; if this is not possible, the rotary sections can be assembled from ready-made bends;
- the coolant inlet must be equipped with a tap, and the outlet with a valve;
- The installation of the register should be carried out with a slight slope in the direction where the supply pipe is located, which ensures that the Mayevsky crane occupies the highest position.
How to improve heat dissipation of registers
The efficiency of registers depends on the heat-transfer surface area, which is relatively small for these devices. In this connection, to improve heat transfer, it is desirable to increase the mentioned area, which can be achieved by welding metal plates. Such elements are installed vertically, providing a kind of ribbing of the pipes. 
It is also possible to create something similar to convection heating. This is possible if you weld not metal plates, but profile pipes that are mounted on the front of the device in a vertical position. As a result, cold air will enter these pipes from below, heat up and exit through their upper part.
Cost of pipe registers
It is almost impossible to indicate the exact price of registers made of smooth pipes, since many factors influence its formation. For example, here it is necessary to mention the individuality of execution, required dimensions, delivery conditions, etc.
Conclusion
Smooth tube registers still find their use, which is more justified in production conditions. As for private houses, you should not use systems assembled using registers of this type to heat them. This will lead to a significant increase in the volume of heated water, which will increase energy consumption, and this is not profitable.
