The supply and exhaust systems provide ventilation of the drainage collector. The incoming stream reduces the vacuum during the drain, which disrupts the water seal in the sinks and toilets. Sewerage ventilation in a private house and multi-storey sector prevents the release of pungent odors from septic tanks and risers in the bath room or bathroom. In the period between drains, the channel works to draw odors and excess moisture.
Purpose of sewer ventilation
At the time of draining, the pressure in the knee of the riser changes, while the water is sucked out of the water seal and smells penetrate the apartment. Gases harm human health, cause allergic manifestations, poisoning, and cause explosive situations. A water trap or siphon is a curved pipe under the toilet, bath, sink and other plumbing devices. Water is constantly present in the knee, which serves as a stopper to prevent the penetration of odors.
The riser with forced feed and exhaust has an effect on the system:
- does not allow evaporation in the bathroom;
- prevents methane or hydrogen sulfide from entering the house, which appears in sewers or a cesspool;
- balances the pressure inside the pipeline.
Building codes allow installation of sewers without installing a ventilation riser for private houses up to two floors high. In such buildings, one-off drains of a small volume of drains are provided that do not overlap the diameter of the drain collector (50, 70 or 110 mm).
The situation changes if it is planned to sewage in an apartment building. Residents at the same time use the drain, the receding mass closes the channel, and safety plugs from the siphons are pulled under pressure. The need for ventilation becomes apparent with an increase in the number of storeys of the house.
Smells penetrate the room if the sewage wells are filled to capacity in the multi-story sector. There is no way for fresh water to enter the drainage line. When draining, even from one apartment, a pressure difference is obtained and on the first floors sucks water from the knees under the sink, bathtub or toilet.
The basic rules of the system device
If plumbing fixtures are not used for a long time, for example, when leaving, the water in the siphons dries, the fumes get access to the bathroom. If there is a ventilation riser in such a sewer, odors do not penetrate the home.
The ventilation system is organized in one of the following ways:
- using a fan riser;
- with installation of a vacuum diffusion valve.
The options are almost equivalent in efficiency, but in multi-story buildings, a system with two structures works better. The diameter of the collectors is chosen the same as in the internal pipeline scheme, because an increase in the size of the riser compared with the cross section of local drainage does not lead to an increase in ventilation.
Sewer ventilation can combine pipes from different materials. PVC elements function without problems in combination with asbestos-cement or metal pipes of the riser.
The vertical channel cuts into the highest section of the sewer line, the pipe of the largest diameter is used for this area. Most often, the connection point is selected at the junction of the toilet with a tee. If there is a common ventilation shaft in the structure, the head of the pipe is brought into it.Otherwise, the channel in the form of the letter G is passed through the wall.
Ventilation system selection
The scheme considers the withdrawal of the head of the ventilation duct from the house and fixation to the external fence with the help of clamps. It is practiced installing the pipe on a septic tank, which is placed at a distance from the walls of the building. The far well reduces the risk of fumes entering the interior.
An external sewer hood is equipped in a private household. If there is no drainage riser on the upper tiers, as happens in buildings for the temporary presence of residents, it is better to mount a vacuum valve.
Considering the circumstances when choosing a system:
- number of floors in the building;
- diameter of collectors of the drainage system.
The fan pipe is provided in the scheme of the autonomous sewer line and in multi-storey wiring, where the transverse size of the pipes is more than 50 mm The valve in these schemes does not crash, but a ventilation system is equipped with an exit through the roof above the roof level.
Be sure to ventilate the cesspool. A PVC collector with a diameter of 100 mm is placed, attached to the wall of the septic tank and displayed above the roof of the auxiliary building. The bottom of the pipe is insulated with a bandage from tow with molten bitumen, the head is protected from debris by sheet metal. Do not put the deflector on top of the wench. in the pipe there is increased humidity and the device mechanism is covered with ice in frosty weather.
Using a fan pipe
In the drainage manifold scheme, the fan pipe serves as a connecting element between the cesspool and the outdoor atmosphere. This method is used in almost all types of sewers and provides effective removal of unpleasant odors. A special mine in the wall of the building for the output of the pipe is provided for at the stage of designing a new house.
The principle of operation is based on the removal of the warm flow upward, and the intake of fresh air is provided by a forced method using a general exchange hood and supply air circuit. Simultaneously with the fan shaft, monoblock modules are mounted for continuous operation of the air suction pump and feed turbine.
Installation of a roof fan prevents the occurrence of a vacuum plug in the sewer riser and odors leak into the house through the side drainage bends. The drainage, pit and ventilation system of the sewer riser is designed in accordance with the provisions of the European standard according to the standards of SP 30.13330 - 2012, which regulates the organization of the internal water supply and outlet pipe.
The ultimate goal of installing a fan shaft is a trouble-free waste disposal design in a cesspool. The riser box and pipes are insulated and waterproofed, equipped with a check valve.
Using a vacuum valve
The device is placed if there is no chance to mount a vertical riser. A spring and a rubber seal are inserted inside the valve. With volley flushing of a large volume of effluent, the spiral opens the shutter and the passage for air flow is freed. The vacuum disappears, the balance is established, the spring pulls the damper back.
The vacuum fixture copes well with the supply of air to the sewer, but is sometimes not considered as a replacement. Do not use only the valve if there are cross-section pipes of 75 and 110 mm or more. The diameter of the manifold corresponds to the same size of the ventilation valve.
The insertion point is the highest point in the system near the sewer risers. More often the valve crashes into a special tee that works on branching the pipeline. The joint is completely sealed with elastic gaskets.
Effective ventilation schemes
Before installation, the vacuum aerator is checked for leaks. The interior space is filled with water from the side where air does not enter the device. Leaks in the housing are detected. The valve is always set vertically, as horizontal arrangement does not guarantee normal operation. The device does not require constant maintenance, but must be accessible for cleaning.
To reduce the ingress of debris, the valve is connected to the circuit 300 mm higher from the pipe installation in the riser. The device is placed in the attic, upper floor so that there is free air flow to it. The valve withstands temperatures from -50 to + 90 ° C. The aerator does not require insulation, as inside between the box and the lid there is air space that serves as insulation from the cold.
A rubber sleeve is used to connect the fan shaft to the drainage collector. The length of the riser increases by the height of the attic, if any, and the tip is displayed above the roof.
In public sewers, where there are several risers, it is allowed to combine the heads into one pulling system, while the mandatory principle is necessarily used. It is not recommended to connect the outlet pipe from the sewer to the chimney.
Installation Rules
The aeration valve is installed in unventilated sewer highways, and is most often used in public networks where there is a possibility of volley flushing. In such a place, the valve is installed every three points. The aerator is used in sewers, where plumbing is far from the riser, and the slope of the pipe is insufficient. The vacuum valve saves materials during the construction of engineering pipelines in the multi-storey sector in that it allows you to get rid of the fan riser. Sometimes a combined installation of two ventilation systems is used.
Rules for installing a fan pipe:
- the head should rise above the roof not less than a meter;
- combining a ventilation system from several risers is done by pipes of the same diameter;
- the outlet of the sewer ventilation shaft is located no closer than four meters from the openings of the building;
- you can not lay the highway under the roof overhangs, so as not to burden the pipes with adhering snow.
Most often, a fan riser is made of a plastic pipe with a diameter of 110 mm. A mine is provided on each drainage collector when several sewer pipelines pass nearby. The tip on the roof is displayed above the chimney by 50 cm.
