Heating water: the best options for heating + analysis of technical features
The water supply system, in addition to internal circuits, includes highways that are laid from the water source to the house.
In winter, due to a sharp decrease in air temperature and cooling of the soil, liquid in the pipes may freeze. To prevent this from happening, it is necessary to arrange heating of the water supply system using one or several effective technologies.
Options for warming plumbing
The problem of heat insulation and heating of pipes arose due to the seasonal change in temperature and, as a consequence, the appearance of a freezing upper layer of soil.
In winter, the freezing depth reaches 0.8-1.2 m on average, and in the most extreme northern points of Russia - up to 2.4 m.
Together with the digging of ditches at great depth it is necessary to equip the tip - to install the caisson, where the pumping equipment is usually located. These are costly and irrational measures, for the implementation of which it is necessary to attract special equipment.
To save finances, to make the maintenance of the water supply system easier, it is laid at a shallow depth, using various means of insulation - from thermal insulation material to a heating cable.
Often the method of heating the underground water supply is chosen based on the installation conditions and considerations of economy. Sometimes it is more advantageous to combine two different technologies.
For example, the cable is mounted all the way through the pipe, including the end lowered into the well, and the part in the ground above is warmed with foam polystyrene sheath.
Method # 1 - use insulation
The traditional and most popular method of heating pipes buried in the ground, as well as “air” water pipes, is mechanical insulation, which is produced using special materials.
The shell is selected based on the conditions of a particular region and particular characteristics of the soil, for example, the presence of high groundwater.
There are a number of requirements for materials. They must have such qualities as:
- low thermal conductivity- a pledge of energy efficiency and economy;
- wear resistance, long service life without loss of basic qualities;
- resistance to organic and chemical substances, as well as soil microorganisms and bacteria;
- no deformationat high humidity and low temperatures.
Typically, manufacturers accompany products with a list of technical specifications that must be considered when choosing alternatives. There are cases when ordinary mineral wool is much more rational to use than expensive polyurethane sprayers.
All the listed materials are relevant, they can be easily found on sale. Preference should be given to insulation with low thermal conductivity, high strength.
It is easier to install one that does not require additional tools, is lightweight and small in volume, lends itself well to processing.
Method # 2 - Air Insulation
This method is used in the public sector and industry, the arrangement in the country of a protective airbag is associated with difficulties. The technology consists in supplying warm air to the canal in which the water supply is located. From above the pipe is closed by any kind of thermal insulation.
This technology has options. For example, if the diameter of the pipe is small, then it is placed in a similar product, but with a larger diameter.
Such an arrangement does not allow the water line to come into direct contact with the ground, and therefore cool. In addition, a small space is created between the walls, through which heated air circulates.
The disadvantage of this method is the impossibility of using it for a water supply system that was fired on the groundIt is relevant only for communications located in the ground, preferably below the freezing level.
Method # 3 - Increased Pressure
There are standards that establish the amount of pressure in the networks for various types of water supply devices. For example, for high-rise buildings the optimal parameters are 4-4.5 bar, whereas in private houses they can be more or less.
The maximum working pressure for water supply systems of private houses is considered to be 6.5–7 bar, but such indicators are rare, more often they do not reach 3 bar. To protect the plumbing from freezing, the pressure in the system is increased, suppose, from 3 to 5 bar.
The main condition is the installation of special equipment, since not everyone is able to withstand such pressure.
More often the increase in pressure is used by public utilities, the owners of country houses use it extremely rarely. If the strength of the system allows, for the period of the winter season the pump is turned off, and the pressure is raised to 5 bar.
Method # 4 - heating with the use of electricity
Installation of the heating cable is considered the most effective way of all active. The principle of heating is simple: an electric current passes through a wire installed inside or outside the pipe, and increases its temperature by converting electricity to heat.
Cable requirements are special. It must be protected as much as possible from the effects of external mechanical stimuli, moisture. The shell must be strong, free of holes and defects.
Consider two types of cables that are actively used for heating pipes that supply water to private homes.
Option 1 - resistive cable
The advantage of the product is a specially selected alloy of metals with high resistance, which causes a large amount of heat generated. Of the two types of cable - single-core and two-core - the second option is more practical.
1-wire requires electrical circuit wrap. This means that during installation, both ends must be brought to the power source.With 2-core is simpler: the first end is connected to a source of electricity, and the second is “closed” by putting a contact clutch on it.
Conductors are protected by a polymer shell, often multi-layered. In addition, a grounding shield covers them from above, and a strong heat-resistant PVC insulation on the outside.
Why choose resistive cable? It has a large heat transfer, in other words, it is very hot and transfers heat to the water pipe. It can be fixed along the entire length of the line, wound around the connecting nodes and flanges.
Additional advantages of the resistive version - affordable cost and ease of installation. All preparation and installation operations can be performed independently.
The disadvantages include the purchase of additional equipment: machines, sensors, control units.It is considered that the end bushing should be factory-made - to ensure safety and proper operation of the heater.
Option 2 - self-regulating heating wire
The principle of operation and cable design are fundamentally different from the first option. Self-regulating systems are recognized as more economical and easy to install.
In terms of power consumption, this kind of cable looks perfect. As soon as the temperature of the air or the pipe decreases, it increases the electricity consumption and generates more heat, and with increasing temperature the conductivity drops sharply.
Efficiency is also increased by heating individual sections of the water supply system. If a Samreg is laid along the street and inside unheated premises, then “street”, colder areas will heat it up more. The more vulnerable the heated zone, the more heat the cable emits.
The advantages of self-regulating systems:
- energy savings;
- heating efficiency;
- distribution by "zones";
- comfortable length.
Unlike the resistive cable, which is sold in finished form and has a certain length, the Samreg can be cut as convenient. Usually on the shell are the cut points, the interval between which is 20 or 50 cm.
There is also a drawback - the heating of extended areas flies in a pretty penny. If a low-power cable can be purchased at a price of 60-75 rubles / m, then the cost of high-quality and powerful reaches 300 rubles / m and above.
Recommendations and installation instructions
It is not as difficult to close the plumbing with thermal insulation as it is to connect heating cables, therefore, we will consider the technical nuances of installation related to electrical equipment.
External installation of the heating cable
Fastening along the outer surface of the pipe is often practiced when it is necessary to heat open sections of water supply located in the basement, basement, caisson.
To fix the wire on the pipe in two ways:
- stretch along the surface along the entire length;
- wrap in a spiral.
The first option is more economical and practical if the power of the cable is enough to heat the pipe. In particularly cold areas, you can apply the second method, but the wire consumption will increase.
Fastening occurs in the following order:
This is the easiest way to install the heating cable.
Recommendations on the device:
- To heat a polypropylene water pipe with a diameter of up to 32 mm, it is enough to fix the cable along one side - which one does not matter. However, if it is necessary to warm the sewage system, the wire is fixed solely on the bottom.
- If there is a choice of insulation, then you need to take a thicker one. Overheating of the self-regulating cable does not threaten, but the heat loss will significantly decrease. The thicker the “fur coat”, the less the Samreg will waste electricity, the greater the savings.
- Aluminum self-bonding is the best material for fastening to the pipe. Acrylic adhesive is not destroyed by heat, which is evenly distributed over the entire heated surface.
- The sun's rays destroy some types of insulation and fasteners, so for open areas it is better to pick up black clamps and tape that does not respond to UV radiation.
If the cable is fastened not in a straight line, but in a spiral, then the insulation will occur according to the same principle - putting on the “fur coat” and fixing it with clamps. Without insulation, part of the energy will be wasted on heating the air.
The nuances of connecting a self-regulating cable
Pull the wires to the pipe from the shield is impractical, therefore, the Samreg is connected to the power cable, which, in turn, is simply plugged in if necessary. The work will require a construction dryer, a knife, a set of heat shrink tubes for crimping and sleeves for connecting contacts.
It should be remembered that electrical equipment in a humid environment becomes more dangerous, so tightness must be given special attention.
Photoinstructions for connection:
As you can see, there are no difficulties in connecting, just all the manipulations must be performed very carefully and consistently.
When choosing a power cable, take into account the location of the outlet.If it is located next to the pipe, you can buy the shortest product, but more often you have to buy a 4-5 meter cord.
It remains to compress the end of the Samrega:
With a sealed end, the cable is fully operational. To prevent the water pipe from freezing, it remains to fasten the Samreg along the entire length of the main line, insulate it and insert the plug into the socket.
In some cases, the installation of an outdoor cable is considered unsuccessful, for example, if it passes through floor slabs or concrete blocks of a well. Then apply the internal installation.
If it is better to use a flat-type product for external heating, then a special cable with a round cross-section and especially reliable waterproofing is suitable for internal heating.
Internal installation requires special care and compliance with certain rules.For example, you can not hold the cord through the nodes where threaded connections protrude from the inside - sharp edges can damage the protective sheath.
Conclusions and useful video on the topic
Instructions for outdoor installation:
Detailed description of the internal installation:
Practical application in country conditions:
If you choose the right method of insulating water supply and perform installation work in compliance with the rules, then there will be no problems with heating the pipes in the winter period.We should take care of the insulation of the highway laid in the ground in advance, and open areas can be insulated at any convenient time..