The heating of a modern private house depends on many factors. This includes the choice of a heating boiler, the presence of underfloor heating systems, the choice of a radiator connection scheme. But the most important factor affecting the energy efficiency of the system is the laying of various heating pipes in a private house, the choice of diameter and installation method.
Types of pipes used for laying heating in a private house
Depending on the project of the heating system of a private house, the material of the pipe for connecting radiators and disconnecting the boiler room may be different. Let’s look at the main options used in the work.
Allocate materials from galvanized steel, based on stainless steel, from ferrous metal. The advantage of such products is high thermal conductivity, which allows you to give off heat not only to the radiators themselves, but also to the supply pipes. With the correct arrangement of the heating system, a sealed circuit is obtained, which eliminates leaks for many years.
From steel water and gas pipes, due to the large internal diameter, it is possible to equip inclined heating systems, which was actively used in the last century. Such systems operate without the use of pumps. Steel is ideal for laying a system of cast iron radiators. Today, corrugated material is made on the basis of stainless steel, which are quite convenient to install.
Due to the high flexibility properties, such systems are often used to equip a boiler room. To bend the pipe, it is enough to heat it to a high temperature, after which it is necessary to bend it, then cool it. Copper is capable of withstanding up to 400 MPa.
A big advantage of using copper is its resistance to temperature differences, so that the walls of the material do not collapse even when the heating circuit is completely frozen. The connection of various sections is carried out using capillary soldering, or using compression fittings. Products are characterized by high coefficient of thermal conductivity, resistance to high and low temperatures, minimal hydraulic resistance, high durability. The main thing is not to combine heating systems by connecting copper and aluminum pipes, since such contact will lead to a violation of the strength of the overall system.
This material is known to all. It has been actively used for many years, easily withstands pressure up to 10 atmospheres, and is connected using fittings and transitions. In those places where it is necessary to switch to metal, a transition is used. Such pipes may well be laid on the surface, since they have an aesthetic appearance, but they can also be “packed” in a finished floor screed, walled up in walls.
For hot water, a polypropylene pipe with metal reinforcement is used, which increases its strength when heated. Installation is carried out using special equipment, which involves heating the pipe itself and the connecting fitting or tee, turn and other elements.
Along with polypropylene, metal-plastic material is used, which is used to equip underfloor heating systems. High strength allows pumping coolant for 50 years or more. Cross-linked polypropylene is also used for underfloor heating systems.
Types and schemes for laying heating pipes
It is important to choose the right pipe laying method. Alternatively, a single-pipe and two-pipe laying system is distinguished.
With a two-pipe laying, the system has a supply and a “return”. This increases the cost of the project, but increases the efficiency of the heating system, since the cooled water directly enters the return pipe, where, using a circulation pump, it is pumped back to the boiler and quickly heated up. That is, the heating boiler needs to spend less energy on heating water than heating it constantly.
As for the one-pipe system, here, with less investment, the consumer initially pays more. The fact is that the cooled water from the radiator enters the supply, where it deliberately dilutes the water by approximately 15-20%. Thus, the next radiator in the system will receive water at a temperature equal to 80-85 percent of the primary values.
Attention! The very last radiator in the circuit will be significantly colder than the first one. This should be taken into account when constructing the heating circuit. Many people think that such problems can be compensated by using a circulation pump, but this is not so, since pumps can only increase the intensity of water exchange with the boiler.
It is the two-pipe heating system that is the most efficient. Now you need to figure out how to connect the radiator. There is a bottom connection, lateral, and diagonal. Of all the above methods, it is most convenient to connect the «bottom». But, such a connection is unable to 100% convert the energy of the coolant into heat for your home, since the radiator is only half warm. The diagonal connection has the maximum efficiency, which involves chasing and laying supply pipes into the wall.
With a diagonal connection, the “supply” goes from above from the heating boiler, and the return goes from below, from where the cooled water is again supplied to the boiler. With a diagonal connection, be sure to choose a two-pipe system so that the coolant circulates faster in a closed circuit.
As for the laying methods, if the heating system changes in an already finished house, for example, in a frame house, then nothing is ditched and pipes are laid over the floor or along the walls. To do this, it is necessary to install a pipe clamp every 70 cm, so that it is important for hot heat supply, otherwise the PVC material is deformed. It is with such pipes that they often work, since their low cost and high durability can reduce the overall cost of the project.
If the house is only being finished, the floors have not yet been filled, then it is most convenient to lay PVC pipes under the finishing screed. As a rule, it is never less than 7 cm, so with this layer of concrete you can organize a hidden laying of polypropylene heating pipes. With proper soldering of the pipe, you can eliminate the violation of tightness. The main thing is to pressurize the system before pouring the finishing screed. For this, a system with a pressure gauge is used, designed to fill the circuit with water, with the help of which pressure is created in the pipe of the order of 2-3 atmospheres. The contour is pressed and allowed to stand for about 5 hours. If during this time the pressure has not dropped, then the installation was successful.
Attention! It is recommended to check the system for operability before pouring the finishing screed. This will help eliminate the narrowing of the plastic pipe. The reason for this is overheating of the fitting.
As for the choice of the connection scheme for radiators, today the beam scheme is actively used. The beam scheme is the connection of each radiator to a central collector, which is installed in the boiler room. From the collector to the heating boiler there is a main pipe, which is often larger in diameter than the diameter of the supply pipes. Thanks to the radial connection, metal-plastic pipes or cross-linked polypropylene can be used.
Here it is not at all necessary to lay polypropylene heating pipes in the wall, as well as to observe rectangular turns. It is enough to lay them under the floor, which will facilitate installation and increase the pace of work. This scheme is considered the best for solid pipes that do not solder.
The general SNIP regulating ventilation and heating is registered under the number 41-01-2003. There are other rules, among which are:
- SNiP 2.04.05-91 (clause 3.58). Regulates the installation of decorative screens and grilles on radiators.
- SNiP 41-01-2003 (p. 6.5.13.). Indicates the need to install shutoff valves, except for rooms with a high probability of freezing of the coolant.
- SNiP 3.05.01-8 (clause 3.18). Regulates the slope of the heating circuit with a pipe length of more than 500 mm.
- SP 40-108-2004 (clause 3.2.1). Regulates the connection of a copper pipe to a boiler with aluminum leads.
Sealing and thermal insulation
Only metal connections have to be sealed. The fact is that when working with HDPE pipes, they are soldered, which does not require additional sealing. With regard to metal-to-metal connections, plumbing linen must be used. This is the most inexpensive way, which, together with the paste, allows you to achieve 100% tightness.
It is necessary to wind the flax in the direction of movement of the object that will be wound onto the thread so that the flax does not turn when screwing on. Instead of flax and paste, you can use fum tape, as well as other means.
As for thermal insulation, there is a special insulation on sale, which is made to fit the diameter of the pipe. It is recommended to isolate the coolant that is supplied from the boiler to the heating radiators. This should be done especially if the pipes lie against the wall under the floor, since it is here that the maximum level of heat loss is observed. As a heat-insulating material, you can choose basalt wool, glass wool, polystyrene foam and other insulation.
Important! Don’t save. When laying underfloor heating systems, it is definitely recommended to install the pipe on the insulation. For the central part of Russia, at least 5 cm of foam plastic is used.
Being at the stage of calculating the heating circuit, proceed from the fact that 1 section is selected based on 1.2 square meters of the room. Do not forget to take into account the margin, if in your room two walls are adjacent to the street, you need to add a margin of up to 30%. That is, for a room of 15 square meters in contact with the street, in which there will be a warm floor, it is recommended to install a radiator with at least 12 sections.
In order to create excess intersectional pressure in the circuit, it is necessary to operate with the diameter of the supply pipe. That is, from the boiler to the main collector there must be a pipe of at least 32 millimeters in diameter. Further, a pipe of the same diameter will go to each circuit, approximately 4-5 meters for each wing. This will create excess pressure in the circuit. Next, you need to narrow down, choosing a diameter of at least 25 mm to each radiator. When lifting water to the radiator, it is necessary to narrow it up to 20 mm, inclusive.
More isn’t always good. It is impractical to use pipes of larger diameter everywhere, since the permeability of water will be better, but its amount will increase, which will lead to heating of a larger volume of liquid. Hence the extra heating costs. The rise of the coolant to the floor above is carried out through a pipe of at least 32 mm.
One radiator comes with an installation kit. These are two cranes, a plug, a Mayevsky crane, 2-3 hooks. Tees, transitions, couplings are considered individually, depending on the number of radiators in the house, their location, and the method of laying the pipe.
Recommendations for operation and repair
The norms of SNiP require the installation of radiators in an ideal geometric plane. It is necessary to set the radiator according to the level, otherwise airing will occur and the coolant will not flow further. It is necessary to install a Mayevsky crane for an aluminum radiator. Aluminum, when interacting with water, releases a gas that must go outside. That is why after a couple of weeks, the pressure in the circuit may drop by 0.1-0.2 from the nominal value.
Important! Consider the nuances. A supply tap must be provided in the circuit, which is delimited from the main water supply circuit in the house by a check valve.
Try to lay polypropylene heating pipes in the floor screed only when the product has a warranty period of at least 40 years. Otherwise, the pipe must be serviceable so that you can always make repairs.
When installing a radiator, make sure that the window sill does not cover it by more than 30%. The recommended height of the radiator from the floor is 6-8 centimeters, from the radiator to the window sill no more than 10. Be sure to install taps on each heating radiator in order to be able to adjust the coolant.
At the bottom of the heating circuit, water must be drained to the sewer. This is necessary in case of repair. At the top of the heating circuit there should be air vents that will allow air to escape without creating an air lock. When using underfloor heating, be sure to install a separate pump on the manifold. It is installed on the supply, in the direction from the boiler to the warm floor. Be sure to use taps at each connection and branch, which will facilitate future repairs.