How does the ventilation of a septic tank made of concrete rings work? Is it necessary?

Ventilation of a septic tank made of concrete rings is carried out to eliminate unpleasant odors and ensure safe living for people in the country or in a private household. Typically, energy-dependent septic tank systems are created in areas adjacent to private buildings, designed to effectively process sewage waste and wastewater due to the bacteria living in them.

A septic tank is a structure in which bacteria live. They develop and multiply quickly during the active processing of organic waste discharged through the sewer system. Processing is accompanied by the release of gas, as a result, silt deposits remain in the septic tank, and clean water goes into the ground. The main problem and danger for people living in households is the possibility of gas poisoning. Therefore, the ventilation system needs to be equipped and done correctly.

Septic tank installation

Structurally, it can be expressed in the following ways:

• Separate containers for sewage water. Liquid enters the first (settlement tank), where it is processed by bacteria, and partial transformation of the waste into solid sediment occurs. In the second, the liquid is clarified, the bacteria complete processes that were not completed in the first container. From the third reservoir, 75% of the liquid purified by the biofilter is distributed into the soil through an infiltrator, used for watering plants, etc. Often, for example, such tanks are constructed from concrete rings.
• A common tank divided into three compartments in which the above processes occur followed by infiltration (septic device Tank).

The principle of operation is general: waste liquid enters through sewer pipelines into septic tanks, is purified as much as possible, distributed into the soil, or used for another purpose.

Many types of septic devices are produced, which are selected depending on the purpose, volume, frequency of operation, expected volumes of wastewater, etc.

Why is ventilation needed?

An important element of a septic system, without which it cannot fully function, is ventilation. The answer to the question of whether ventilation is needed in a septic tank is most often positive. Let's take a closer look at why you need to ventilate a septic system:

• in the second tank (compartment) there are aerobic bacteria that process wastewater after the first tank. These bacteria are necessary for the most effective purification of water from solid inclusions. The vital activity of microorganisms is associated with sufficient access to oxygen. Which is ensured by the flow of air from a ventilation pipe installed inside the tank lid;
• a product of the vital activity of aerobic and anaerobic bacteria - a mixture of gases that, at a certain concentration and accompanying conditions, pose a certain danger to human life. Among them: hydrogen sulfide, methane, carbon dioxide, volatile arsenic salts, phosphorus compounds, etc. Some of them are explosive or cause serious harm directly to human health. Their discharge must be ensured using the supply and vent pipes;
• When flushing waste water through the toilet, a vacuum occurs, creating a vacuum space. If there is no vent riser, the water seal of the toilet may be torn off, then the gas mixture from the septic tank will rise into the house. It sometimes gets inside the premises when flushing water, this is immediately determined by the unpleasant odor.

When a septic structure is equipped with ventilation, the gas flow moves up the drainpipes, and then rises through the drain riser and exits the system to the outside.

Conditions for good work

To get an effectively working septic tank, you need to pay attention to several necessary conditions

Overflows, ventilation

Overflows should be located below the sewer pipe through which the waste flows directly into the receiver. The minimum difference is 100 mm. To ensure that the liquid is immediately directed to the lower part of the container, tees are installed at the ends of the overflows.

To ensure the flow of fresh air into the septic tank, high-quality ventilation is necessary. If there are several cameras, then it is mounted either in the first or in the last container. The minimum diameter of ventilation risers is 100 mm. The inflow must be positioned so that it is always above the surface of the wastewater. Gases are vented from the receiver through a sewer riser leading to the roof of the house. It is equipped with deflector caps.

Setup

To ensure the most efficient recycling of waste, it is necessary to provide the septic tank with microflora that will break down organic matter. The first way to find bacteria is to take sediment from an actively operating station. The optimal volume of the substance is 15% of the tank volume.

An alternative is special biological products containing aerobic, anaerobic bacteria, or bioactivators (universal, narrowly targeted), which include several types of microorganisms. The former need a good flow of fresh air, the latter can work in a closed environment.

Which septic tank is better? The answer to this question is clear: this is a factory product, durable, sealed, and maximally efficient. How to properly install a septic tank in a private house? Carry out all stages correctly. Since the efficiency of the treatment plant directly depends on the quality of installation, it is better to delegate such large-scale work to the shoulders of professionals. Or involve a friend who has already installed similar structures and therefore knows everything, or almost everything, about the process.

The following video will tell you how to choose a septic tank for your home:

Types of ventilation

Depending on the location of the vent riser, there are different types of sewer ventilation:

• Internal ventilation. The vent pipe is located inside the house and is a ventilation riser to which plumbing fixtures are connected. Water is discharged in one direction, and a mixture of gases moves in the opposite direction and is discharged outside the house. The diameter must be at least 100 mm so that the waste material occupies approximately 1/3 of the total volume, the rest of the space is intended for air.

It cannot be combined with a general house ventilation system so that the exhaust air does not mix with other flows and does not enter the premises of the house.

• External ventilation. The sewer pipe is located outside the house, often mounted to the wall of the house away from the windows, or to another building on the territory of the house, depending on how the sewer system is located. The pipe is not connected to the plumbing riser, but is included in the drain pipe in the section from the house to the septic tank.

Innovative water seals

A simple scheme for cleaning the siphon.
In Europe they came up with a way out for such situations. For example, you can use siphons without a water seal (siphons with a dry water seal). Such siphons can be installed wherever conventional siphons are installed. They are indispensable in country houses where water can dry out or freeze. The installation of a dry siphon may be the only way to operate a house without human intervention. It is especially recommended when ladders are rarely used, at elevated air temperatures or in frosty conditions. In cold weather the water seal freezes, in hot weather it dries quickly. Taking into account these features of local sewage treatment facilities, it is recommended to pay special attention to the quality of construction work when installing sewerage equipment and to the quality of plumbing. If possible, it is better to minimize the number of plumbing fixtures and not use cheap and low-quality drains.

Scheme of waterproofing a septic tank made of reinforced concrete rings.

The practice of operating plumbing fixtures in Europe has shown that there are several tricks that can be used to improve the performance of sewer ventilation. To use these opportunities and not limit yourself in comfort when living in a house with local sewerage, you need to clearly know the theory of ventilation and have a good understanding of modern technologies for home sewerage systems. Complex septic tank systems and an advanced understanding of resource conservation have raised the question of more advanced devices. If you forgot to do something when building a house or didn’t plan for it, new technologies and new equipment can help out.

What does a septic tank ventilation system consist of?

In a sewer well made of concrete (or plastic) rings, the following elements must be installed:

1. Fresh air supply pipe. It is carried out from the street directly into the wastewater capture chamber. It must be installed to feed aerobic bacteria with oxygen, since without it they will simply die (unlike anaerobes, for which oxygen is harmful).
2. A pipe for removing accumulations of gases formed during the processing of household waste by bacteria. This is essentially an exhaust hood that ensures the removal of methane, hydrogen sulfide, and various phosphorus compounds that are harmful to the structure itself and to people or animals on the site.

Septic tank ventilation system diagram
These are mandatory structural elements of the system. Additionally, the exhaust air duct can be equipped with a fan to create a more stable and strong draft. In fact, such a solution is not necessary: ​​air exchange will be sufficient if the natural system is installed correctly.

Principle of operation

The system’s operation scheme is quite simple; it can be described step by step as follows:

1. A drain riser or drain valve is inserted into the sewer system of the house. Through them, air is sucked into the sewer pipe when flushing (water in the bathroom, in the kitchen, from the washing machine, when flushing the toilet, and so on). This is necessary so as not to create a vacuum inside the system, which will suck out the water seals.
2. Together with household waste, air from the plumbing point (bathtub, shower, sink, toilet) enters the central sewer pipe, which runs from the house to the septic tank.
3. Through the pipe, household waste is discharged into the sewer well, where a large fraction of the waste ultimately settles. The chamber is gradually filled with oxygen (air).
4. Through internal channels (they are mounted above the water level), air enters the following tanks.
5. Inside the tanks, bacteria are fed with wastewater and oxygen. It turns out that in each chamber the air is polluted one by one.
6. An exhaust pipe is installed in the last tank, which is discharged to the street. It is through this that polluted air comes out.

How to install a ventilation system if the house does not have a vent riser or valve?

Some houses can be built without installing a vent riser or valve. This is allowed if, for example, it is a small building in which the plumbing points are not used at the same time (for example, they do not take a shower and do not turn on the washing machine at the same time). In this case, too much vacuum is not created in the sewer system, and it will not suck in the water seals.

But in this case, air will not flow inside the septic tank, so it will be necessary to organize its flow in another way. To do this, you need to cut a vertical outlet upward into the section of sewer pipe that runs along the street from the house to the septic tank. It must be brought above the surface of the earth, to a height of at least 50 cm. In this case, the drains flowing under pressure will suck air from the street through it.

Creating ventilation for a septic tank (video)

Main rules for the design and installation of a ventilation system

When organizing such a system, the following rules should be observed:

1. The sewerage pipeline should be installed in such a size that its diameter is 30% larger than the expected volume of wastewater. This is also required to protect against the appearance of a vacuum plug during flushing, as well as to improve the flow of air masses.
2. For normal air flow, the end of the fan riser must be led out through the roof of the building. In this case, the riser must be straight, otherwise there may be air resistance and disruption of its circulation. In principle, it is not necessary to vent the vent pipe into the atmosphere: it can also be vented into the attic. As an option, you can install a vent valve instead, which will not need to be vented anywhere: it will suck in air directly from the bathroom in which it is installed.
3. To protect the channel from various debris, insects and rodents, it is necessary to mount a mesh and install a protective umbrella.
4. The passage of air masses from one concrete container to another is carried out through pipes between them. Therefore, these pipes must have a large enough diameter to avoid clogging.
5. The most common diameters for pipes (used for ventilation) in low-rise construction are 50, 110 and 125 mm.

Ventilation passage design

Let's consider the features of forced ventilation. When installing it, the usual cover is replaced with an inspection hatch. In such a hatch it is possible to arrange an air window. This hole not only acts as an outlet for exhaust gas, but also ensures constant circulation of fresh air

This is extremely important for the normal course of fermentation processes.

An additional hole for the ventilation pipe is installed at the top of the cesspool. Experts recommend choosing communications made of plastic - they are more resistant to constant exposure to aggressive environments and have a long service life.

A fan is connected to the base of the pipe in the pit. You can use a regular deflector with protective caps or buy a special device for the cesspool. To connect to the network, an additional electrical wire is laid into the drain tank, which is directly connected to the fan contacts.

Fan for cesspool

Natural ventilation uses pipes that are installed directly on the cesspool cover. The length of such a pipe can be different - it depends on the desired efficiency of the system. But the depth is strictly standardized - the pipe is installed in the drain 20 cm above the maximum fill level of the tank.

Bacteria in a septic tank

Ventilation in a septic tank made of concrete rings is the best option. Despite the fact that installing the system will entail additional costs, ventilation cannot be abandoned, as this is fraught with serious consequences.

The following bacteria live in a septic tank:

1. Anaerobic - located in the first chamber of the system, in the water column, they process all household waste (various types of detergents, organic matter, etc.), and emit explosive methane, which is not noticeable to the bike.
2. Aerobic - they live in a film directly on the surface of the water and are engaged in processing waste that was not eaten by the first bacteria. They emit hydrogen sulfide, which is poisonous and smells bad.

In addition to hydrogen sulfide and methane, septic tanks also emit volatile arsenic salts, carcinogens, and various types of phosphorus compounds. If ventilation for the septic tank is not provided or performed incorrectly, all the products of the “work” of bacteria go through the sewer system back into the house, at best creating a stench, at worst – severe poisoning and an explosion.

Independent design

In home-made installations, as well as in a cesspool tank, mainly anaerobic processes take place. Effluents entering settling tanks are divided into fractions. In this case, the heavy fraction settles to the bottom. Natural processes of anaerobic fermentation begin in the sediment, resulting in the decomposition of organic matter with the release of methane, carbon dioxide and other gases.

These gases must be removed from the chambers, and to prevent vacuum from occurring in them, it is necessary to ensure the supply of air. This is why septic tank ventilation is needed. To design a ventilation system, you need to remember the basics of physics, namely the laws of movement of air masses. Warm air always rises, and cold air always sinks.

Since the temperature of the effluent is usually higher than the ambient temperature, a difference in air pressure is created outside and inside the chambers. Therefore, when constructing ventilation for a septic tank, it is usually combined with a vent riser.

How does the system work?

• In septic tanks, in any weather, heat exchange occurs between the working environment (wastewater located inside the chambers) and the external environment (ambient air);
• If heat exchange occurs, then there is also natural air exchange. That is, the ventilation of the installation is carried out due to the pressure difference.

Location Features

The pit should not be located too close to the house

To prevent the unpleasant smell from disturbing the inhabitants of the house, you need to pay attention to the fit of the collection hatch. The outdoor toilet must be attached without gaps

Ventilation in a toilet with a cesspool can be arranged by installing a regular PVC sewer pipe with a diameter of ten centimeters. It is attached to the wall at the back. A hole for the pipe is drilled on the floor and lowered about ten centimeters. The upper end extends beyond the roof by more than twenty centimeters. The bottom of the pipe must be insulated with tow, soaked in advance in a bitumen primer. The exit is covered with a tin sheet, treated with foam or cemented.

When ventilation is installed in a cesspool without a toilet, installation is carried out in the same way. A pipe is inserted not far from the hatch, the length of which is calculated depending on the height of the outlet. If you attach an exhaust motor to the upper end, the stench will not spread throughout the area, even in the summer heat.

By constructing the ventilation system in this way, it will be possible to avoid the accumulation of harmful gases and, as a result, the occurrence of an unpleasant odor in the toilet itself.

In addition, ventilation of the cesspool will prevent the harmful effects of fumes from feces on the wooden structure. Thanks to this, the life of the country toilet will significantly increase.

When building a toilet with a cesspool, it is best to ensure that the toilet is located separately from it. It is easy to connect them using a regular sewer pipe with a large cross-section. In this case, a ventilation outlet is connected to the pipe itself through a tee. Then excellent ventilation will be guaranteed, but only if a drainage system is additionally provided for the toilet.

One way or another, the ventilation system here can be constructed in two ways:

• natural ventilation involves ventilation through increased pressure in the pit;
• with forced ventilation, air exchange will be realized through fans that are powered by electricity.

Installation of natural ventilation

Above, we briefly mentioned the installation of natural ventilation for the toilet. Let's look at this process in more detail.

The air from the cesspool will be exhausted into the atmosphere through a vertical ventilation pipe installed on the rear toilet wall. The end of the outlet at the top should extend beyond the roof.

The air will move due to the difference in pressure between the toilet and the atmosphere. Then the smell will not enter the room itself and the gases will be effectively removed outside.

The inlet of the sewer pipe must be no lower than the level of sewage filling. Then it will never be blocked by waste.

To ensure sufficient air movement, the exhaust cross-section is made more than ten centimeters, and the upper end is raised more than seventy centimeters above the roof.

To secure the pipe more tightly to the toilet wall from behind, plastic clamps are sometimes used. Then you can be calm about it even during strong winds.

In addition, the junction of the inlet pipe of the ventilation pipe and the cesspool must be carefully sealed.

Installation of forced ventilation

The most effective method of ventilation is forced. It can only be implemented if there is electrical power at the site. But when used, you don’t have to worry: all gases from organic decay will be completely removed. The device is installed as follows:

1. Even when a toilet is being built, you need to think about the location of the ventilation system and build a window for ventilation. It will be a source of lighting on one side, and an opening for air flow on the other.
2. Electricity is supplied to the toilet. A suspended structure for this will be the easiest way. When laying the electrical supply line, use a cable that has special protection from external influences.
3. The fan is selected. In order for the air circulation to occur normally here, a model with a power of up to 300 Watt will be sufficient.
4. It is best to first select a fan, and only then form the necessary hole for it. It only moves air in one direction. Usually this is an air expulsion to the outside.
5. To prevent vacuum from forming in the toilet, there must be holes for air to flow in. Their role may well be played by the gap located between the bottom end of the door and the threshold.

How to ventilate a homemade septic tank?

Let's consider how to ventilate a septic tank assembled from concrete rings, since this construction option is one of the most popular.

Organization of ventilation of single-chamber septic tanks

A single-chamber septic tank is the simplest version of a treatment plant; it differs little from a conventional filter cesspool. Used in summer cottages or in houses with minimal water consumption. The ventilation of a single-chamber model is assembled from two pipes:

• The lower pipe should have a diameter of 100 mm, it is installed on the cover;

Advice! It is important that the ventilation pipe protrudes above the ground. Otherwise, flood waters will flood the septic tank through the pipe.

• The upper pipe (ground part of the ventilation) has a diameter of 50 mm; it is inserted into the lower pipe by installing an adapter.

Organization of ventilation of a three-chamber septic tank

For a residential building in which the family will live permanently, a three-chamber septic tank is usually built. In such a private house, a varied set of plumbing fixtures is installed, so the water consumption will be quite large. In such conditions, the construction of a cesspool is impractical, since it will constantly overflow.

The three-chamber design of the septic tank will provide a more effective degree of purification. When installing ventilation of this design, the ventilation pipe is installed only in the last chamber, which is built for post-treatment and drainage of wastewater.

In the first two compartments of the settling tanks, ventilation is not installed. From the last section of the septic tank, water is discharged through drains (perforated pipes) to filtration sites. Drains are laid underground in ditches filled with sand and crushed stone. Ventilation of such a system is carried out as follows:

• The end of each drainage pipe must be brought to the surface;
• Ventilation pipes should protrude half a meter above the ground;
• Protective canopies must be installed on ventilation pipes. This is necessary to protect the system from precipitation getting inside.

Advice! A ventilation drain system will not only provide a better degree of cleaning, but can also be used to flush pipes during maintenance.

So, in order for home-made local sewage treatment plants in a private house to work effectively and, unlike a cesspool, not to emit unpleasant odors, an air exchange system must be installed. Properly designed and correctly assembled septic tank ventilation from rings will provide normal conditions for the cleaning processes to take place.

What types of cesspools are there?

Cesspools are designed to collect a wide variety of liquid waste. Making such a structure is not at all difficult. You can use rings cast from concrete, old tires and any other material. There are several types of cesspools:

• absorbing type;
• sealed type;
• septic tank

It doesn’t matter which cesspool you use, but you should know that its depth should not be more than three meters. Otherwise, there is a risk of contamination of groundwater, and this has a bad effect on the environment.

The cesspool should not be located close to the house.

When constructing it, it is necessary to select the correct tank volume. Then you can avoid overfilling and unpleasant odors.

It is necessary to periodically clean the cesspool using special antiseptics. There are even products that destroy detergents, paper and other nitrates. After treatment with this preparation, the bad smell will disappear and the liquid in the pit will decrease. If you constantly perform such actions, then you will not have to pump out the liquid soon.

How to ventilate a septic tank with your own hands

In order for a self-made concrete septic tank to work smoothly, several principles must be followed:

• To prevent blockages in the pipeline, the diameter of the pipes must be at least 30 percent larger than the expected volume of waste.
• The drain should be as straight as possible. Otherwise the air will encounter resistance.
• Protective visors will not only prevent moisture from entering the pipes. Together with the mesh, they will prevent foreign objects, small birds and insects from entering there.
• All joints must be sealed.
• The pipeline must be carefully insulated from the ingress of ground moisture. Otherwise, water from the sewer drain pipe coming from the soil can clog the passage and interfere with the exchange of oxygen.

The procedure for constructing septic tanks from concrete rings

To arrange ventilation inside a septic tank made of concrete rings, you will certainly need the following materials:

• meter reinforced concrete rings - 3 pieces for each chamber;
• cast iron hatches for each container;
• reinforced concrete slabs with holes for each chamber;
• plastic pipes with a diameter of 12 cm (their length is calculated by the distance between the house and the septic tank), as well as connecting pipes;
• bitumen or liquid glass to provide waterproofing;
• bottom concrete slab or mortar for pouring the base.

To make ventilation inside a septic tank from concrete rings, you will also need shovels, strong buckets, ropes, a powerful hammer drill, a ladder and a lifting mechanism for installing the rings (they weigh about 400 kg). The main stages of constructing a ventilated septic tank are:

1. Digging a pit. The event is carried out before delivery of reinforced concrete rings to the territory.
2. Installation of rings. At the same time, the pipeline is being assembled.
3. Complete sealing of the system, with special attention paid to the bottom of the containers.
4. Installation of ventilation risers that can eliminate unpleasant odors.
5. The final stage. Gradual backfilling of soil, its compaction.

When implementing each stage, it is necessary to carry out the work with outside help. Each operation requires the implementation of reliable insurance measures.

Non-standard ventilation solutions for sewer systems

Non-standard solutions, which at the same time do not contradict safety rules and sanitary requirements, can be a solution if a sewer hood in a private house is installed after the building itself is built. Under such conditions, the implementation of the classical scheme can cause certain difficulties.

Installation on the external wall of the house

If the ventilation pipe is routed along the outer wall of the building, from the outside it will resemble a regular drain and will not spoil the appearance of the house. The only difference will be the height of the upper part, which in any case will be above the roof level. The most common pipe diameter for such sewer ventilation is 110 mm. When choosing an installation location, you must comply with the requirements regarding the permissible distances between the fan outlet and windows (balconies, loggias) specified above.

Fence installation

Installing a drain pipe and fixing it on a fence is virtually no different from installing it on an external wall. The only feature is the greater distance of the ventilation outlet from the building. When choosing this option, it is important to take into account the location of the house and outbuildings on the neighboring site. Don't bother your neighbors with the smell from your sewer.

Ventilation to the septic tank

A sewer ventilation system in a private house, connected to a septic tank, in some cases may be considered the best option. Purification devices and storage tanks, according to the rules, must be installed at a certain distance from the house (depending on individual conditions - from 5 to 20 meters). This ensures that no unpleasant odors enter the house. In addition, it is not difficult to draw a similar conclusion during the construction of a house, when renovating and improving living conditions.

Before choosing the most suitable ventilation scheme for the sewer system of a private house, it is necessary to carefully study all the existing conditions and nuances of operating the existing sewer system.

Limitations and recommendations

If, after familiarizing yourself with the regulatory requirements, you are still full of doubts as to whether you need ventilation of the sewer system or not, we offer simplified explanations:

• If you are designing a house, then know that the district architect will not approve your project without drain outlets if the future building has more than 2 floors;
• If the number of floors is 1-2 floors, then the number of toilets and bathrooms matters. A fan output is not needed if there is only 1 of them.

But that’s not all - even if your project includes only 2 floors with one bathroom and one bathroom, their location will play a role:

• A drain pipe is needed if the bathtub and toilet are located at different levels;
• A connection to the roof is needed if a pipe with a diameter of less than 100 mm will be used to lay the sewer;
• A connection between the sewer system and the atmosphere is required if there is a swimming pool in the house;

Scheme of work (in a multi-storey and private house)

In both options, the principle of operation is the same, but there are also differences. In a private house, you can install a riser on the outer and inner walls, but in a multi-story building this is technically impossible.

Another difference is also in the method of installing the system. Most often, when designing a nine-story building, the ventilation diagram is drawn taking into account the characteristics of the building, its height and typicality. In low-rise construction, it is possible to deviate from the basic norms of SNIP and design according to the wishes of the owner of the premises.

Advantages and disadvantages of natural air exchange

Like any engineering system, the natural variety is not without its drawbacks, but also has significant advantages. To definitely decide whether to arrange it or not, it is worth comparing the list of pros with the list of cons.

Positive sides:

• Easy and inexpensive installation. This is the cheapest option for organizing stable air exchange.
• Low maintenance costs. If the system does not have mechanical devices, then it only needs periodic cleaning.
• Energy independence. Does not consume electricity, except for the installation of additional electrical appliances.
• Extremely quiet operation. Features reduced noise.
• Engineering flexibility. Ventilation can be modernized and equipped with various devices. It is possible to adjust the system performance.

Negative sides:

• Instability of traction. Its dependence on atmospheric pressure and specific weather conditions. The effectiveness of natural ventilation in summer may be insufficient.
• Formation of drafts. In winter, strong drafts can not only cause discomfort to the residents of the house due to drafts, but also significantly increase heat loss. This results in increased costs for heating the premises. It is worth noting that there are different ways to solve this problem.

Anyone can organize a natural ventilation system in a private home. Its imperfections are compensated by the simplicity of its design and minimal maintenance costs.

What is a fan boner?

(hereinafter referred to as FS)

It is needed to ensure communication between the sewerage system and the external environment, that is, to ensure that the sewerage system is not closed.

Most often this is a plastic or polyethylene pipe of the same diameter as the sewer. However, sometimes cast iron and metal are still used.

The sewer pipe is actually a continuation of the sewer pipe, except that water should not flow through it; this is the so-called dry pipe.

Installation methods

If the house has two floors and a bathroom on each, then according to building codes and regulations, a FS should be installed rather than using a vacuum valve. There are two installation methods:

• Interior.
• External.

In the first case, it is mounted completely inside the building and is brought out through the roof to the street, while it must be remembered that the minimum height from the roof to the head should be 1–1.5 meters.

It is best to run the pipe through the ridge to prevent it from being blown in by the wind. In some cases, a narrowing of the outlet diameter is allowed. However, professionals do not recommend doing this; less air will flow into the smaller size, resulting in the sound of “choking” in the room.

When passing through the floor slabs, there is no need to insert a “sleeve” between the pipe and the concrete cavity; it is better to foam it with polyurethane foam and seal it with mortar.

During warm weather, the ventilation pipe tends to expand, and in cold weather, on the contrary, it narrows. If the riser is not securely fixed and dangles in the hole, it may come out of the joints, and it will be very difficult to insert into place.

In the second case, installation is carried out at a certain distance from windows and entrance areas. For window openings and doors, the distance should be at least 400 centimeters horizontally.

It must be fastened securely. Otherwise, in winter, ice and wind will break the system.

The external ventilation method is not very different from the internal one; it is also installed above the roof ridge. Places where the roof slope hits the fan outlet should be avoided; snow and large volumes of water can damage the pipes.

After installation, it must be insulated using glass wool or mineral wool. Different regions use their own insulation thickness. In middle and northern latitudes there is a layer 100 millimeters thick. In the southern and central region, 50 mm is allowed.

This measure will avoid freezing of the air duct during the cold period, as well as the accumulation of condensate on the outer wall of the shaft. Recently, polystyrene foam coating, which is stored in metal cylinders under high pressure, has become a very popular material for ventilation insulation.

This composition is applied using a special gun and is securely fixed, forming a heat-insulating layer.

Operating principle of a sewage disposal machine

The main elements of any sewage disposal machine are: a reservoir (tank) for transporting liquid, a vacuum pump, a pipe for pumping water from septic tanks, sewer wells, drainage systems of car washes, natural reservoirs, etc. The operating principle of such equipment is as follows:

1. One end of the pipe is connected to the machine, and the other is lowered directly into a container of liquid.
2. Using a vacuum pump, water mixed with sludge is pumped into the tank. The process continues until the septic tank is completely empty or until the tank is full.
3. Disposal of reinforced waste products is carried out in strictly designated areas, taking into account environmental standards.

Theoretically, the transport tank and pumping equipment can be installed on any vehicle chassis that meets the technical requirements. In Russia, as a rule, GAZ, KamAZ or ZIL are used for such purposes.

Machine for collecting and recycling wastewater based on GAZ 3309

The maximum distance within which water can be drawn depends on the length of the pipe (hose). The standard length, regulated by the manufacturer, usually varies between 6-15 m. By individual order, this parameter can be increased to 25 m. Some sewer trucks use additional hoses, which allow increasing the length by another 5-10 m. However, even this is sometimes not possible enough to clean a septic tank located at a great distance from the roadway. In this case, additional measures will be required from the owners of the site.

Vacuum valve

(hereinafter referred to as VK)

In a one-story house, as well as in a building where plumbing fixtures are installed only on the first floors, it is allowed to use VK instead of FS.

In order to provide ventilation, a special mechanism can be installed in a small system, which is mounted using a tee connection.

It works on the reverse principle. The device has a sealed curtain with spring resistance. When a vacuum occurs in the sewer, the vacuum draws in the valve and with it the air from the room, and when the balance is restored, the spring closes the valve again, preventing the smell from leaving the pipe.

How to install

The installation of an air duct can be combined with the laying of an air duct, but you need to remember several nuances with this combination:

• The valve should not be higher than the fan riser.
• In some cases, it is possible to install the mechanism not only on a vertical, but also on a horizontal pipe.
• If the length of the horizontal section of the shaft with plumbing fixtures is more than 8 meters, install two valves at an equal distance from each other.

How to make it yourself

To do this, a plastic plug is inserted into the tee, in which several holes are drilled in a circle. So that they can be closed, a flat disk with a diameter slightly larger than the halo of holes is cut out of foam rubber.

Then you will need a simple wood screw and a loose return spring. In order for the foam rubber to press down and close the holes after the valve operates and the pressure in the system normalizes, a plastic or iron plate is inserted between the spring and the disk.

Now the screw is screwed into the cover from the reverse side. It is worth considering that the performance of a valve made independently will be several times lower than a factory one. In the factory, all calculations and drawings are carried out, which are based on all the indicators of the future sewer system, and the volume of air required to be supplied inside is calculated. It is unlikely that such actions will be possible to perform under domestic conditions.

Note : You can combine the use of a vacuum device and the FS system. In this case, the valve is installed at the end sections of the sewer pipeline.

Aerators

Scheme of a treatment facility with post-treatment in aeration tanks.
Another example of a new device is a sewer aerator. It happens that a plumbing fixture is installed too far from the riser. In this case, when using a plumbing fixture, a vacuum occurs in the pipe. It may not occur every time, but only under a certain combination of conditions for using appliances throughout the house. This phenomenon is unpredictable and unpleasant, since air from the septic tank immediately begins to flow into the room through the missing water seal.

The water seal often breaks down if the wrong diameter of the sewer is chosen for draining water or the passage in the pipe is too clogged and silted. To avoid such situations, it is necessary to take sewer pipes of the maximum possible diameter, the same throughout the entire system. This is especially true for kitchen sink drains, which often become clogged with grease. When the pipe fills during water drainage, a vacuum occurs in the pipe and the water seal breaks.

Anaerobic treatment system followed by MBR cleaning.

In this case, a new device such as an aerator helps. A vacuum will not occur in the pipe if air enters the system when water is drained. To do this, make a local riser of a certain height, which should end with an aerator. At the moment when a vacuum arises in the pipe and water begins to be sucked out of the water seal, the aerator is activated (the lid opens and air appears in the pipe). The water seal remains in place and the smell does not leak out. To prevent a vacuum from arising, a small amount of air is enough; it is sucked into the riser from any room in the house. The advantage is that there is no need to put the riser on the roof.

This could be in the attic, bathroom or storage room. This small riser with a diameter of 50 mm can be sewn into the wall and a ventilation grill can be made into the sewing. The height of the riser is important so that water does not overflow from it. For example, if you place an aerator under the bathtub on the outlet pipe (below the water level in the filled bathtub), then when a vacuum occurs, water will flow into the aerator and pour out onto the floor. Installing the aerator this way is a mistake. Risers with aerators can be installed locally if a problem arises.

How to choose pipes?

Mostly plastic or polyethylene is used, as well as polypropylene.

You will also need 45 and 90 degree bends, tee connections and couplings. It is best to use polyethylene products, since attic spaces are not always heated. An aggressive environment - frost and sun - can break the seal.

Polyethylene is very elastic and responds well to changes in weather conditions. In each case, the amount of material must be calculated separately; we can only say that in any project there must be at least one compensator and instead of bends of 90 degrees, it is better to use 45.

As for the tool, each employee chooses it for himself. To secure or cut a pipe, you need a hammer drill or a screwdriver (it all depends on the walls of the building), an angle grinder with adjustable speed, or a hacksaw.

Installation of sewer system ventilation and septic tank

First, it is necessary to ensure air ventilation of the septic tank, which is located on the street. When laying a sewerage pipeline, waste pipes are installed in it using connecting tees, which are then brought to the surface.

If the system is long, then VCs are installed every 7–8 meters. If possible, it is better to bring the underground risers as high as possible, but this does not always work out that way.

An air duct is also required on the septic tank itself. The mounted branches of the pipeline perform the function of taking air into the cavity of the line and supplying it inside the septic tank. If there is an autonomous wastewater treatment system, then the installation of the specified FS is mandatory, since aerobic bacteria living in the storage tank and processing waste require air, which will flow into the main line and into the tank itself.

In this case, the installation of check valves is not recommended, since the oxygen supply to them is limited and a deficiency of the nutrient medium for microorganisms may occur.

The second stage - installation of rings and connection of pipes

The first rings are mounted above the second; this principle cannot be deviated from. Next, reinforced concrete slabs are laid with hatches made in them. At this stage, you can release the truck crane; it will no longer be needed. You should take care of the holes intended for pipes. It is also worth noting that the design of the septic tank ventilation also requires its own opening, located above the 2nd septic component. As for the first chamber, there is no need to organize air flow there.

Next, pipes are inserted, and the main sewerage pipeline should be brought into the 1st chamber. As for the slope of the sewer system pipe, it is more than three degrees required. The main thing is no less.

Installation of pipes along the external wall of the building and on the roof

It is desirable that this be a gable wall. Before entering a bathroom or room, especially if the plumbing fixture itself is still a few meters away from the outer wall, you need to stretch an additional air duct along the outer wall, which also runs above the roof. This measure will ensure better circulation within the system.

When the sewage system inside the house is assembled at the highest point, after the plumbing fixture, a tee is installed in the pipeline with the socket facing up. Then a pipe of the same diameter is inserted into it and brought out through the ceiling to the roof. If there are various obstacles along the route (rafters, chimneys, etc.), they will have to be bypassed without changing the angle of inclination using bends.

Products from the store often do not fit in size. You'll have to cut it with a grinder and then chamfer the end to make it easier to join the bell of the next piece.

On the roof itself, the shaft exit should protrude at least 50 centimeters above the roof. Then a headband is put on its end, which will prevent moisture and snow from getting inside.

Moreover, it is unacceptable to install a weather vane or deflector; this can lead to the formation of ice and subsequent blockage of the pipeline. It is enough to put a small umbrella or visor

Throughout the entire external ventilation, inspection fittings must be installed, which look like a standard tee with a socket and an inspection window with a lid. This part is necessary to solve problems of diagnosing the internal state of the highway and performing preventive maintenance. If a blockage occurs or a foreign body enters, through such a unit it is possible to accurately determine the clogged area and eliminate it.

Important! The rubber bands must be left in the sockets and lubricated with oil or sanitary sealant. Also, if the length of the pipe was changed by cutting, a chamfer must be made at the end of the part, otherwise the cut end will rest against the sealing ring and lift it inside the socket.

System construction process

The installation of exhaust ventilation in the kitchen or bathroom begins with marking out the entire system. After this, materials are selected and calculated. Never rush into calculations. Everything needs to be done carefully and calmly.

When designing, remember that ventilation is important for its functionality with the ability to make maximum use of all conditions in each room. If you make a mistake, you will have to use mechanical air blowers, which will significantly increase the cost of the system.

For normal operation of a gravity-type system, it is desirable that the air ducts have as few turns as possible. It is recommended to install turbine deflectors on exhaust pipes rising above the roof - they will increase the outflow

Installation steps:

1. Ventilation design.
2. Purchase of equipment: sewer pipes, installation products, fasteners, fittings, mounting metal tapes.
3. Installation of brackets and clamps at the locations of ventilation communications.
4. A ventilation riser is assembled from large pipes.
5. Assembly and installation of air ducts.
6. Connecting all branches to each other.
7. Sealing of connections. There is no particular need for this, but it won’t hurt.
8. Installation of fans and valves, if provided.
9. Installation of ventilation dampers.

The end of all types of installation work is testing the system for operability. All actions consist of checking traction. To do this, you need to attach a piece of paper or a napkin to the exhaust ducts.

Design or development of a circuit

Creating a ventilation project begins with basic calculations and collection of information, then:

• Calculate the air exchange rate throughout the entire house. This indicator depends on the volume of all premises, their purpose and the number of residents. In living rooms, the air should be completely changed once every 1 hour, and in technical rooms (toilet/bath) - at least 3 times every 1 hour. By adding up the resulting figures, we obtain a performance indicator, taking into account which the diameter and height of the ventilation equipment will be selected.
• Draw a diagram of the movement of air flows. Immediately estimate the position of the intake and supply channels.
• Draw a diagram of the air ducts. For now, ignore the detailing, stick to the rules and try to fit the system in without complicating the design. This is the most difficult stage of the work. Hiding ventilation from bulky plastic pipes is not so easy.

The sketches are ready. Take some time to think about what devices you will have installed in the system and where they will be located.

Rules for installing a ventilation riser

1. The air duct must be the same diameter as the sewer.
2. The intersection of the vent riser and the ventilation of the room is unacceptable.
3. When laying a pipeline along the external wall of a building, the distance from windows and doors must be at least 4 meters.
4. The fastening must be secure and airtight.
5. An “umbrella” or headband is installed at the end of the socket, and it should not interfere with the passage of air.
6. It is allowed to combine several air ducts into a common network and only then should it be routed above the roof.