Automated water supply of a private house from a well

Recommendation points

• Well construction. Caisson
• Selection of pumping equipment
• Installing the pump
• Installation and laying of the pipeline
• Insulation of the pipeline
• Hydroaccumulator
• Controllers
• Pump power supply

Are you the happy owner of a small country house or are you just going to build a serious country mansion? Or maybe you are just a rural person with experience who finally decided to bring water into the house and make the life of your family a little more comfortable? In any case, the issue of organizing autonomous water supply will sooner or later come up for you..

Even in a house outdoors, it is very difficult to give up such familiar benefits of civilization as a bath, toilet, washing machine, mixer on the kitchen sink. And someone just needs a pool, a sauna with a shower, a fountain in front of the house … It is considered normal to spend about 150 – 250 liters per person daily. This is drinking and household water, as well as irrigation. In general, options are limited only by the homeowner’s imagination and financial capabilities..

Do not think that uninterrupted water supply to a home is a luxury that, for monetary reasons, is inaccessible outside of city apartments. Yes, very often in rural areas there is no centralized water supply even in projects. Sometimes there are common networks, but they are unreliable (low pressure, shutdowns, etc.) or the water in them does not meet any quality standards. The way out is the search and extraction of water from the earth.

If earlier people got by with digging shallow wells and scooping up life-giving moisture with buckets, now, with the advent of new technologies, it has become possible to automate the processes of lifting and distributing water from deep underground sources, including artesian wells (up to 200 meters from the surface).

Well water is usually cleaner than well water, as it is at a decent depth and protected from surface contamination. In addition, its reserves can be many times greater than in wells, and in fact, to supply a large household every day, up to 4 – 5 cubic meters of H2O may be required, and this is without intensive watering.

An automated autonomous water supply system must ensure uninterrupted water supply to the building, regardless of the season and weather conditions, without systematic human participation. To do this, it is necessary to carry out a number of complex and time-consuming activities, but the game is worth the candle.

Well construction. Caisson

Let’s assume that you already have a well. It’s time to start arranging the caisson. This is a kind of chamber, rectangular or made in the form of a cylinder. The main task of the caisson is to protect the well from groundwater, freezing of pipes and equipment at subzero temperatures, and foreign objects entering the casing.

Often such structures are made of metal, reinforced concrete, plastic. The option with the use of brickwork has the right to life.

Old brick masonry

One way or another, around the head of the well, a hole should be dug about 2 meters deep and about 1.5 X 1.5 meters in area. At its bottom, a reinforced concrete slab with a thickness of 100 mm is poured. On top of it, masonry is made in the form of a rectangular well. The resulting camera should rise above the ground at least 200 mm, from above it can be covered with sheet metal, slate, or, again, a concrete slab with a hatch and holes for power cables. Inside, on the walls of the caisson, it is worth installing embedded elements for the device of a possible intermediate overlap, thermal insulation (for example, expanded polystyrene). Embedded can be used to secure ropes and ropes on which pumping equipment is lowered into the well.

The caisson rises above the surface

Particular attention should be paid to waterproofing the caisson so that it does not fill up with groundwater. The outer side of the masonry is coated with bituminous mastic and hot glued over with sheet waterproofing materials (such as “euroruberoid”).

Selection of pumping equipment

Now, one of the next tasks facing the developer is the competent choice and installation of a suitable pump, because it is reasonably considered the heart of the system, its most expensive element..

Most manufacturers of pumping equipment offer a very wide range of their products, there is a choice for all occasions, for any wallet.

Important indicators for which pump options should be considered are the required head and predicted water flow..

It is necessary to calculate and take into account at what height from the mirror (dynamic level) it is necessary to raise water, what is the length of the horizontal pipeline, how many consumption points are planned to be simultaneously used, what is the debit (amount of water produced) of the well, what is the diameter of the casing.

The main thing is that the pump performance (the volume of pumped water per unit of time) does not exceed the debit (so that there is no “dry running”), but also not too small. The best indicator is minus 10-15% of the debit.

The diameter of the pump casing is selected based on the diameter of the well (it should not be much smaller), however, even here you need to know the measure so that there are no problems with its extraction, for example, for replacement / prevention. It is worth considering possible curvatures, irregularities and local narrowing.

Installing the pump

In order for the entire water supply system to remain under pressure, a check valve is installed immediately on the pump outlet. Then the pressure pipe will be constantly powered, there will be no air in it. In the case of only outdoor (surface) use of the well, the valve is not installed, then the water leaves after shutdown, the pipes remain empty – nothing freezes.

After the check valve, a compression sleeve is installed to connect the pipeline.

Downhole pumps have special lugs through which a steel cable or nylon rope is threaded. It is better to use a galvanized rope in a PVC sheath from 4mm in diameter. To fix it, clamps made of stainless materials are used.

With the help of plastic ties with an interval of 1.5-2 meters, the pipe and the power cable are attached to the cable, without tension.

The pump is lowered into the well so that the distance from it to the bottom is at least 500 mm. There are also restrictions (indicated in the equipment passport) on the permissible water column above the pump, then, perhaps, you will have to deepen less.

To lower the pump and especially to raise it from the well, when the weight of the pipeline filled with water is added to the weight of the equipment, it is very convenient to use a wooden drum with a crank, like on wells, it is on it that a safety fastening cable is hooked.

Gate from the old well

The drum is mounted on a sturdy metal structure located above the caisson. It is recommended to build a small canopy of arbitrary shape above it, especially since under it you need to start a power cable with a waterproof outlet for outdoor use.

A crossbar is mounted above the caisson for attaching the lifting drum

Before the first start, the pump should lie in water for 5-10 minutes, fill.

Installation and laying of the pipeline

For external pressure water supply, polyethylene pipes are excellent. They are sold in coils and do not require welding / soldering and additional connections over extended areas. Such pipes are inexpensive, they are strong and durable, sufficiently plastic and reliable..

The water supply from them is assembled quickly and easily, even in sub-zero temperatures. Connections are made manually, without specialized equipment or tools, by means of mechanical socket clamps with rubber O-rings. Couplings (saddles) are reusable, they have a wide variety of configurations (elbows, straight and angle couplings, threaded transitions, tees, etc.).

Attention! Use a properly labeled food pipe.

The inner diameter of the pipe is selected based on the characteristics of the system and pumping equipment. The minimum allowable figure is 25mm (25 * 2.3 PN 10).

To prevent the water from freezing in winter, pipes along the street should be laid in a trench dug below the freezing depth. The bottom of the ditch is freed from stones and other protruding objects, then sand filling is made and a pipe is laid, previously wrapped with a heat insulator with a closed cellular structure.

Particular attention should be paid to the place where the pipeline enters the house. Very often, passing the foundation, the pipe is bent along the radius, and it rises to a dangerous height for freezing, moreover, in the underground space, especially near the outer wall, subzero temperatures are possible. In this place, it is advisable to use an angle pipe socket and thermal insulation. It will also prevent the formation of condensate, because the water from the well is cold enough.

It is also worth installing a detachable connection (coupling) in the caisson, so that, having disassembled it, it is convenient to remove the pressure pipe without kinks.

There are two pumps in the old wide well. Pipes have collapsible connections

Insulation of the pipeline

If the water conduit is planned to be used all year round, it will be imperative to take care of its competent insulation. As we already said, the most reliable way is to lay the pipes below the freezing depth, where the temperature does not drop below zero. However, sometimes this depth is large enough for some latitudes – up to two meters, which entails certain difficulties and serious labor costs, or for some technical reason, it is not possible to go deeper to the required distance.

When the water supply is located above the freezing depth, perhaps the best option is to heat the water pipe with an electric cable. A special heating cable is wrapped around the pipe in coils, or attached to it linearly with aluminum tape. Sometimes the cable is laid inside the water pipe. The heating cable can also be used in relation to local sections of the water conduit, for example, at the entrance of the pipe into the house, as the most dangerous place.

The self-regulating cable is very convenient to use, it does not require the use of control blocks, thermostats, etc. It changes its power depending on the temperature of the environment in which it is located, which makes it possible to efficiently consume energy, since different loads are installed in different sections. On average, a properly selected and installed heating cable consumes 9 – 12 watts per linear meter.

It is better to place a water pipe with a cable in a casing made of a propylene sewer pipe of a larger diameter and insulate it with foam plastic, expanded polystyrene or other similar materials..

Regardless of how the heating cable is installed, the pipeline should be insulated!

There are a lot of materials suitable for a water pipe insulation device. Their main feature is minimal thermal conductivity and low moisture absorption rates. The so-called “shell” made of polystyrene or expanded polystyrene, which is made of two parts with a spike lock, has very good performance. From sheet polystyrene, boxes of various shapes that cover the water conduit are sometimes made. The pipe in the trench can be poured with penoizol, thus making a sealed structure. It should be noted that thermal insulation materials made on the basis of foamed rubber, basalt wool are also used for these purposes..

Due to its low cost and excellent performance characteristics, the most widespread is the thermal insulation of a water supply system made of foamed polyethylene. It is very practical and quite durable, which is provided by the elasticity and closed cellular structure of this material. Foamed polyethylene is very easy and convenient to work with; only a knife and scotch tape are required for its installation. Foamed polyethylene of various diameters is produced with a two-meter stocking with a special seam-blank.

Water filtration

Very often water from a well is not potable without filtration for a number of reasons. This is especially true for new and shallow wells – up to 40 meters. Bacterial contamination; excess iron, manganese, hydrogen sulfide, fluorine, boron; nitrates and nitrites; hardness salts; mechanical impurities (sand, chalk, rust, unwinding fibers …) – that’s what you have to expect trouble from.

To get a working filtration system, it is necessary to take into account such factors as the performance of the water supply system, oxidizability, pH level, and all other water parameters. Therefore, you should make a water analysis in a specialized laboratory, and based on the results obtained, select filter equipment..

For cleaning from mechanical impurities, washing mesh filters with a mesh size of 20 to 500 microns are used. The same function is performed by cartridge filters, which are a housing made of plastic or steel and located inside a working element that periodically requires replacement. High-speed pressure filters – columns filled with filtering material – have excellent performance..

Water is purified from iron using reagent sorbents with a certain service life (potassium permanganate, chlorine, ozone …), or reagent-free filters with new non-aggressive fillers. In a reagent-free filter, iron is removed, for example by oxygen oxidation.

Removal of excess calcium and magnesium is carried out by using ion-exchange resin in filter units, which is capable of absorbing hardness salts on the surface of its granules. It is believed that filters based on ion-exchange resin, made using the latest technologies, are universal and capable of performing the entire complex of water purification.

Carbon filters purify water from organic acids that give it unpleasant taste, color and odor.

To disinfect water, filters based on an ultraviolet lamp have most often been used recently, the radiation of which kills spore and vegetative forms of bacteria. They do not introduce any elements like chlorine into the water, do not change its properties and do not cause pipeline corrosion, such as ozone.

The filtering equipment is installed in a heated room after a pressure switch and a hydraulic accumulator. The filter unit begins with the installation of a coarse filter, followed by iron removers and softeners, at the end there is an ultraviolet lamp. The system can then be equipped with a reverse osmosis unit. Before and after the filters, collapsible American valves should be installed for easy removal and maintenance of equipment. It is often necessary to connect a drainage outlet to the filter unit for flushing and regeneration measures.

Hydroaccumulator

Almost all modern autonomous water supply systems without the use of a storage tank are equipped with hydraulic accumulators. This is a welded metal vessel, painted with a powder composition, inside which is a replaceable rubber membrane. Outside, it has a nipple for pumping air and a flange with a threaded socket for connecting to the water supply.

Horizontal hydroaccumulator

The main task of the accumulator is to reduce the number of pump on / off cycles, prevent water hammer, and create some water supply.

A certain air pressure is pumped into the non-working chamber of the vessel by a car pump, approximately 1-2 atmospheres (depending on the set intervals for the automatic operation). Water entering the accumulator expands the membrane, which fills almost the entire internal space. When the downhole pump reaches the set pressure in the system, it will shut off. By opening any tap, you get water from the accumulator (the membrane is compressed under the action of compressed air) until the pressure drops to the mark set for turning on the pumping equipment. Thus, the pump does not react in any way to frequent small water intakes, therefore its resource increases greatly.

The volume of the accumulator is selected in accordance with the characteristics of the pump and the system as a whole. Options are available from 24 to 500 liters. Large vessels can be used as an emergency supply of water in the event of a temporary lack of power supply, because water from the accumulator enters the pipes under the action of internal pressure.

Controllers

A lot of instruments are now available that control many parameters of the borehole pump..

As for the on / off device, the PM / 5 mechanical pressure switch is considered the simplest and most reliable. It, according to the established pressure indicators (most often from 1.2 – on to 3.2 bar – off), closes or opens the contact group responsible for the power supply of the pressure equipment. Sometimes it is necessary to change the factory settings of the relay when assembling the system from separately selected elements. This is easy to do by rotating the clamping nuts and checking the on and off thresholds with the pressure gauge..

Even if you are very careful about the choice of pump performance in relation to the flow rate of the well, it is imperative to install protection against “dry running”. If the water level falls below the inlet of the pump, but it continues to work, it may overheat and fail..

For example, the LP / 3 relay sensor reacts to a critical pressure drop (sign of lack of water) in the system and turns off the pump. To start the water-lifting equipment, it is necessary to forcibly close the contacts by pressing a special button. The system is also filled when the pump is turned on for the first time..

The black device is a pressure switch, the blue one is a dry run sensor

Sensors of “dry running” on the duct have a reed switch that starts the pump and react to the movement of water through the pipes, or rather its absence.

Dry-running controllers are installed in the pump power circuit in series with the pressure switch.

Automation elements (pressure gauge, pressure sensor, dry-running switch, hydraulic accumulator, inlet and outlet piping) are assembled using a fitting with five leads of different diameters (inch and? Inch).

Combined pump control units are commercially available, they include a flow sensor, a pressure switch, and a pressure gauge. Such devices are compact and convenient, they are often used in systems without a hydraulic accumulator..

All automation is recommended to be located in dry heated rooms, the caisson is not suitable for this, no matter how spacious it is.

Small utility room for household needs

Pump power supply

The correct cross-section of the supply conductor is selected according to the pump power. As a rule, a three-core (neutral, line, ground) copper cable with a cross section of 2.5mm is sufficient². It is rational to take power supply directly from the shield through a separate circuit breaker (from 10 amperes).

The wires go to the control devices and, through the relay contacts, go to the well through the air or in the ground. Since most pumps have an integrated, protected cable terminated with a plug, an outdoor socket is installed in the caisson area.

In the absence of electricity, the water in the house also naturally disappears. The way out is to use a gasoline or diesel generator for emergency situations..

Sometimes, for the correct operation of automation and even pumps, it may be necessary to use voltage stabilizers / normalizers, especially for imported equipment, which requires fairly stable and accurate characteristics of the incoming electricity.