As a source of water for autonomous water supply most often use a water well. Its operation is made seasonally or year-round. If you plan to take water in the winter, you need to think about how to insulate the well for the winter and avoid problems with water interruption, equipment breakage and pipe rupture.
We will describe how the heat insulation of an independent water source is made, excluding the formation of ice jams in the system. With us you will learn how to insulate the trunk of the production and outgoing from him water lines. Our tips will help determine the best way and material for insulation.
The article thoroughly discussed the basic rules and subtleties of the organization of the system of protection of independent water supply from freezing. Schemes, photo-illustrations, video tutorials are attached for visual perception of the topic.
The content of the article:
- Features of well protection from cold weather
- Basic principles of caisson insulation
- Installation of casing for the tip
Insulation of the underground pipe system
- The use of modern insulating materials
- Use of heating cable
- Additional protection during the installation phase
- Conclusions and useful video on the topic
Features of well protection from cold weather
Illiterate arrangement of water intake development often creates obstacles for the normal operation of the source. Especially acute errors and omissions occur in the winter.
The operation of a well that is not protected from frostbite by reliable thermal insulation during the frost makes it difficult to form ice on the water surface and the formation of ice jams in the pipeline.
As a result, pumping equipment and the system as a whole works with increased load. A large cork can deform or completely break the HDPE pipes, of which most often external water lines are constructed.
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If year-round operation of a water well is supposed, its part located above the level of seasonal soil freezing is required to be warmed.
It is mandatory to carry out the warming of the caisson, in which the well head is located, a hydraulic tank and a water supply automation device are installed
In the case of the arrangement of the tip, not immersed in a caisson, it is better to protect it with insulated box, for example, made in the form of a well house
The outer part of the pipeline operating in the winter of the water supply system is laid below the depth of freezing of the soil layers. In this case their warming is not required.
To prevent the formation of ice jams at the entrance of the pipeline to the house, it is necessary to warm the area from the level of frost penetration to entering the heated room
For thermal insulation of the underground part of the insulated area can not use hygroscopic wadded and loose foam options. In the case of their use the pipeline must be tightly wrapped waterproofing.
The best choice for insulating the wellbore and the underground part of the water supply system is a polyurethane foam shell with an external bituminous sheath
Work on well insulation should be carried out in the period of its arrangement. If heat insulation was not applied immediately after drilling, then make it better in summer
The purpose of well insulation for the winter
The location of the equipment in the caisson
Making the ogolovka in the form of the house
Features of laying water pipe
Warming of the outer section of the pipeline
Polyurethane shell for pipes
The optimal period for insulation
Traffic jams and ice crust appear in the well if the water intake works “not at full capacity”. Those. if there are breaks in the operation, sufficient for the crystallization of water. Even if the owners of the autonomous water supply system do not count on such pauses in the functional, means of their prevention in the form of a device for the insulation should be carried out.
Events weatherization water system held from the point of entry into the house to a depth that is 20-30 cm below the level of seasonal soil freezing. This value can be found in the collections on building climatology of the joint venture under number 131.13330.2012 and in SNiP under number 23-02-99.
The depth of freezing is determined in accordance with the conditions of the region and the type of soil covered by the zone of freezing. Its value is obtained empirically based on many years of observations.
Proper arrangement of water wells will eliminate the formation of ice and ice jams in the water supply system (+)
If the water supply system is introduced into the house through the basement of an unheated basement, it is also necessary to warm the branch before entering the heated room. The use of materials for insulation of objects located in the ground has its own specifics.
Insulation should have the following properties:
- Do not absorb water or have a protective waterproof shell. If water is absorbed into the insulation and then freezes, then with a high probability due to an increase in the volume of water during the transition to ice, the layer of insulation will be destroyed.
- Under the pressure of the soil does not lose its properties. The pressure of the earth’s mass from above or its movements can crush the insulation and increase its thermal conductivity.
- Not to be of interest or not to be exposed to insects and rodents.
The last point is very important, because in the summer the mice can pull the insulation along nests, and in the winter they can dig holes in it to get to the warm pipes. All this will lead to direct access of cold to the elements of the water supply system.
Protection of insulation from mice and insects - one of the main problems when insulating objects located on the street under the ground
Sometimes, to protect a well and a water supply system from cold, it is sufficient to perform procedures that do not require special knowledge of the principles of insulating an underground water supply system. Water that is fed into the system from the depths has a positive temperature (usually from 7 to 13 degrees Celsius).
If there is a risk of water freezing, then it is necessary to adjust the system operation mode so that the water supply takes place in small portions, but as often as possible. Continuous circulation of groundwater, the temperature of which, by definition, is above 0 ° C, will prevent icing.
It is possible to warm the cap and pipes during not very cold winters in the southern regions of Russia or when the aqueduct is deep, without special refinements using sawdust or straw. To do this, it is necessary to dig a hole near the tip and a ditch along the occurrence of the water supply pipe, cover them with dry sawdust or straw and bury the hole again.
It is necessary to carry out this procedure every year in the fall, so that by winter the sawdust and straw do not have time to rot. To eliminate freezing for a longer time or if the proposed methods do not guarantee a positive result, a different approach is needed to solve the problem.
To restore water supply in the winter is harder and more expensive than to carry out competent insulation taking into account the design features of the system and climatic conditions
A caisson for a well is a reservoir buried in the ground, located above the wellhead. It is necessary for convenient access to the main elements of the water intake system for the purpose of repair and regular maintenance.
Inside the insulated caisson mounted hydroaccumulator, pumping equipment and filters to take them out of the house and remove noise. If the equipment is placed in a heated room, the caisson is not satisfied, and install the adapter.
Both the well with the caisson and without it must be warmed so that the direct contact of the elements of the water supply system with the frozen rocks is excluded from the entire thickness of the freezing soils.
Basic principles of caisson insulation
Even if the wellhead is located below the depth of soil freezing, the main part of the caisson is above this mark. If its walls have significant thermal conductivity, then negative temperatures can drop to the tip and the water in the system will freeze significantly lower than indicated by the Construction Climatology.
By geometry caissons for wells may be cylindrical or rectangular, it does not affect the method of insulation. From the standpoint of the costs of insulation, objects of a cylindrical shape are more profitable, and from the standpoint of simplicity mounting the material supplied in the format of rigid slabs, it is easier to insulate rectangular objects forms.
The material caissons can be concrete, metal and plastic, although concrete structures are now rarely used because of the complexity of their installation and the fragility of concrete when exposed to moisture.
Metal and plastic caissons are waterproof, so with internal insulation you can ignore the resistance of the material to water
Warming the caisson from the inside is relevant if its body is sealed due to the properties of the material or to perform reliable waterproofing. In this case, there is no need to protect the insulation from moisture.
In addition, ground movement or other external impacts will not affect the integrity of the insulation layer. As a rule, with internal insulation products are used based on foam or expanded polystyrene.
Warming the caisson outside is carried out to preserve the internal space or if bulk materials are used. Outside, it is desirable to insulate plastic structures, protecting them from severe frosts, in which plastic becomes brittle.
External insulation is carried out with any materials, but it is necessary to take into account the possible movement of the soil, the impact of water and the risk of damage to the layer of insulation by insects and rodents.
When using external insulation, it is necessary to protect the material from water, insects and mice, otherwise over time it will be necessary to carry out work anew
Since heat losses in any well insulation will still occur, their compensation due to heat influx is necessary. It will occur anyway due to the positive temperature of the water in the pipes passing through the caisson and the generation of heat by operating devices.
If there is a possibility that the insulation may not be enough, then you can install an elementary heating element complete with a temperature sensor.
Since the inner space of the caisson is small, then with normal insulation as a heating element is enough to use an ordinary incandescent lamp with a power of 40-60 watts or heating wire length 3-5 meters
Installation of casing for the tip
If in designing the water supply the caisson was not provided, and the tip is above the level of soil freezing, then it can be insulated using an additional casing, Ø which is more than Ø stationary casing two thicknesses insulation.
To install an additional segment casing it is necessary to dig a hole around the tip to the depth of freezing of the ground plus 0.3 m and insulate the tip. An additional pipe should be installed on top, and the space between the casing should be filled with glass wool or mineral wool.
It is undesirable to fill the gap between the two casing pipes with spray-insulated insulation options due to the inability to control the uniformity of the application of the heat-insulating layer.
Protecting the cap against frost by installing a casing requires less material and is simpler than warming a caisson
The pipe should be metal, as in the cold plastic becomes more fragile and ground movement can damage it.
It is also necessary to ensure that there is no water in the space between the casing and the tip. Mineral wool loses its insulating properties when moisture is absorbed, and polystyrene foam shell can be deformed when ice forms.
To prevent wetting before laying the insulation in the gap between the casings it is necessary to install an oil seal. The external size of the gland should be equal to the diameter of the additional casing, and the internal - the diameter of the main casing.
Insulation of the underground pipe system
Warming of the water line leading to the house may not be necessary if it is placed below the ground freezing level. However, the deeper the water supply system is located, the more complicated its installation and repair.
In this case, pipe insulation may cost less. thermal insulation material and be easier on the level of work required.
With the lower liner, you need less insulation costs, but it requires more complex work during installation and in the case of repair.
The use of modern insulating materials
The oldest and proven method of pipe insulation is filling the trench with expanded clay. Mineral wool without a waterproofing outer casing is not used for underground communications.
Now the number of different types of thermal insulation offered for sale allows to solve this problem for any temperature conditions. For the device of underground lines in areas above the level of freezing, they produce a “shell” of polyurethane foam and polystyrene foam with foil waterproofing sheath.
For insulation of underground branches of water supply, insulators are made of PPS and PPU with waterproofing sheath. As an alternative solution, HDPE pipes with heat insulators already attached to them are used.
Consider the main types of material that are most often used for insulation of underground water supply:
- mineral wool or glass wool is compressed under the weight of the earth, therefore, if it is used, additional work is needed in the form of creating a durable casing;
- basalt fiber covered with aluminum foil for waterproofing is a rather expensive material, but it is easy to work with;
- polystyrene and polystyrene is easy to cut, retains heat well, but protection from rodents is necessary;
- polyurethane foam keeps heat well and has moisture resistance.
For knots and turns there are special shaped shells, which is convenient for the installation of insulation. They allow without any problems to carry out the installation of insulation in the pipeline sections of any degree of complexity.
To quickly and reliably insulate the water supply line using sprayed polyurethane foam. In such cases, the pipe must be laid on a pillow of expanded clay, because the bottom of the pipeline may be uncovered insulation material.
Sprayed polyurethane foam has a very low thermal conductivity, does not get wet, does not break under the weight of the earth and it is not gnawed by mice and ants
For hard-to-reach places where the use of bulk materials is problematic, you can use a thermal paint - a modern universal liquid heat insulator. Such paint can be applied as an ordinary brush or roller, or by spraying. In addition to the main function, it protects well metal pipes from corrosion.
Use of heating cable
The principle of thermal insulation materials is reduced to the so-called “passive protection”. Thanks to its proximity, the water in the pipes will not be cooled until it flows to the heated room.
It should be understood that in a closed system without an external source of heat, the insulation system does not prevent freezing, and only increases the period until the crystallization of water under the influence of negative temperatures.
In case of infrequent use of water from the well, such insulation for the winter may not be enough. In the case of interruptions in work, it is necessary to heat the pipes for more than a day, with water drained from them, using special electric cable.
There are two ways to place the heating cable: inside the heated pipe and outside.
To enter the internal heating cable, a special system of a tee and a terminal coupling is provided, which makes it easy to carry out this procedure.
For internal installation use special cables. They are non-toxic, meet the increased requirements of electrical protection (although experts recommend connection via RCD) and they are sold complete with a sealed end coupling. Installation of such a cable is simple and it is carried out through an ordinary tee.
The main advantage of the option of indoor installation is the high efficiency of the heating system and, as a consequence, the reduction of electricity costs. The main disadvantage is the complexity of the cable through the curved sections of the pipeline.
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Installing a heating cable will eliminate the formation of ice jams in the water supply system, prevent the occurrence of emergency situations.
When the pipeline is buried below the seasonal freezing of soils, there is no need to lay the heating cable along the entire branch
If the pipeline is laid above the depth of seasonal freezing of soils, the entire line is equipped with a heating cable.
The pipe heating system is installed throughout the outer part, passing through the building structures
Cable heating is laid in two ways: by winding outside the pipe and pulling inside
After entering the water supply system into the house, the pipes also require heating in rooms without stable heating.
The installation of the heating cable is made not only on the pipeline, but also on all types of valves and fittings
In order to reduce heat loss during operation of the heating cable system, the pipes are wrapped with heat insulation, if necessary, closed with waterproofing
Operational method of heating pipes
Heated section of water supply
Heating cable on the underground line
Warming pipes in front of the house
Cable laying inside the pipe
Construction of water supply in the basement
Cable laying on fittings
Thermal insulation over cable
When external installation of the cable is necessary, first of all, to ensure its tight fit on a well-cleaned surface. The cable is attached to the pipe using aluminum tape, then the tape is carried over the entire cable so that it does not come into contact with the insulation material.
Plastic pipes are pre-coated with foil for even heat distribution.
To increase heat transfer, you can fasten several cables linearly or in a spiral. In the case of a spiral pitch of 5 cm, the length of the conductor will increase by 1.7 times with respect to the length of the covered water pipe.
Installing a thermostat allows you to significantly save energy, because the heating is turned on only when the set temperature is reached. The optimal values of the temperature of inclusion is considered from 3 to 5 degrees Celsius.
The heating cable is always installed complete with thermal insulation, otherwise the heating of the environment will be very expensive.
Additional protection during the installation phase
For the well version using submersible pump Before long downtime, the system is preserved. For this purpose, pipelines are laid with a slope towards the water source, and a check valve is installed at the outlet of the supply pipe from the barrel.
After turning off the pump, it, together with the supply pipes, is removed from the production, and water flows by gravity into the well. When using this method, it is desirable to have no “pockets” where the water might remain. The disadvantage of this method when using metal pipes is to increase the corrosion rate of the metal.
One of the rarely used methods is the creation of a “pipe in pipe” system, when a pipe of a larger diameter is put on the water pipe, which is insulated outside. The air gap thus formed serves as an additional protection against cold.
If you introduce an external pipe into the basement of the house, ensuring air circulation between the layer and the basement, you can get additional heating of the underground water supply.
Heating of the air gap due to the temperature of the technical room is one of the easiest ways to provide heat in the immediate vicinity of water.
Another option - forced circulation of water. To do this, it is necessary to install a second pipe leading from the basement to the well and a system of taps to switch the water supply to the house or to this pipe.
Including a scheduled pump, you can pump warm groundwater into the system, and pump cold water out of the system into the well. This option is convenient for a long absence of the owners of the house, when there is no water consumption.
There is a widespread opinion, including on the Internet, that it is possible to prevent freezing of water by creating excessive pressure in the system. However, the temperature of the transition of water to the state of ice decreases by only 1 degree for every 130 atmospheres of static pressure. To build a water supply system that can withstand such pressure is unrealistic.
Conclusions and useful video on the topic
Video # 1. Elementary weatherization of the walls and caisson cover with foam inside:
Video # 2. Construction of a well using a caisson, with the disclosure of the topic of insulation:
The freezing of the well and the water supply system is fraught with not only the cessation of the water supply, but also damage to the equipment and elements of the system, for the repair of which will require money and considerable effort. It is better to perform quality insulation work once and to get permanent access to water for many years.
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