The sewer system in a private house is as much a part of engineering as heating with water supply. A feature of this infrastructure can be called close interfacing with a number of other communication networks. In many ways, these are indirect connectives, sometimes playing an auxiliary, and sometimes a paramount role. The nodes of the second kind include the combination of ventilation and sewage due to the transitional communication structure.
System purpose
Sewers and liquid household waste are collected in the sewer, which creates an unfavorable sanitary and hygienic background in the pipeline and adjacent parts of the house. Without an air vent, bad odors with vapors can create conditions for the formation of pathogenic bacteria and microorganisms, which will be much more difficult to get rid of. For this reason, sewer ventilation is organized for the home in one configuration or another. Most importantly, the communications of the ventilation system should have a natural or forced air vent, providing free circulation of air flows.
Ventilation system design
At the stage of development of the project, an arrangement of ventilation circuits connecting the sewer pipeline and the street air environment is drawn up. The main calculations are done in relation to house interchanges. In the classical scheme, the vertical riser (fan pipe) forms the basis of such ventilation. The project should consider its location and diameter. As for the first nuance, it is recommended to place the riser as close as possible to windows and other openings directly connected to the street. The smaller the distance to the exit points, the better. The diameter for the channels of a private house averages 110 mm, but, again, a lot will depend on the technical capabilities of the riser device.
Do not forget that the communication channels of heating, ventilation, water supply and sanitation architects try to combine into one highway to save space. That is, one large canal connecting the first and second floor can include heating, water supply and standard ventilation lines. However, this principle of pipe alignment does not work in relation to a fan pipe precisely because of sanitary restrictions. This riser must be placed separately with its own insulation.
Pipe selection
Many experts recommend immediately contacting the sewer pipes, since they will allow organically continuing the air branches directly from the sewage. In addition, such pipes are cheaper and made of plastic, which in itself facilitates installation work. But choosing pipes of this format for sewer ventilation, two points should be considered:
- A strong rupture in diameters is possible when connecting the channels to the main ventilation system - sometimes the sections do not coincide, not to mention the materials used to make the pipes. Leveling such inconsistencies with adapters is much easier and safer in the infrastructure of the sewer system.
- Technical plastic is not the best solution for the ventilation system of a residential building, as it can release harmful substances when heated. Nevertheless, its use is allowed in the organization of exhaust systems that do not imply the possibility of inflow.
It is possible to refuse sewer pipes in favor of stainless and galvanized analogues. These are heavy pipes, it is difficult to mount and join them, but at the same time they are durable, reliable and environmentally friendly.
Installing a fan pipe
The riser is preferably made from the same pipe from which the sewer channel or the septic tank is made. It is desirable that this be a high-strength and heat-resistant plastic. By the time of installation, a vertical channel with a roof outlet should be prepared. If it is not, you will have to change the layout of the bathroom, forming a hole in the ceiling for the pipe.
The sewer ventilation fan stand is fastened with clamps, sealing materials and holders, the ends of which are fixed to the wall. It is advisable to use not rigid, but “floating” plastic clamps with the possibility of regulation. The pipe rod must be oriented strictly vertically without slopes, bends and with a minimum number of transition nodes. Especially in a two-story house, it is difficult to do without segmented installation of the fan pipe, but in this case, if possible, the number of parts should be reduced. The connection is carried out by thermal soldering using sealants and solid repair clamps.
Installation of vacuum valves
In the upper part of the riser, a valve must be installed that will operate at moments of rarefied air. Such regulation will not allow odors to leave the riser directly in the room. The valve itself is provided with a cover with a spring, which normally covers the valve outlet, and when internal pressure rises, it opens and releases harmful gases to the outside.
How to install a vacuum valve for ventilation in a sewer system? Installation is carried out as a plumbing joint. The main thing is to provide for such a position of the device so that the possibility of wiring through several small-format channels is preserved. If you follow the advice of specialists, then usually the valve pipe is seated in a fan pipe, after which it is sealed and sealed. It is important to ensure the mechanical fastening of the device, since its head part weighs quite a lot, and the reference point is one - in the connection node with the riser. Therefore, it is necessary to foresee 2-3 rigid clamps fixed to the wall on the passage line of the exhaust pipe.
Riser insulation
In hot weather, ventilation works efficiently due to the natural difference between indoor and outdoor temperatures. During operation, constant heat transfer occurs, so the flows freely rise up according to the law of thermodynamics. But is it necessary to make a forced ventilation installation in the winter? With constant use, the riser will not freeze, as heated wastewater is warmer than air. But in other cases, and especially in cold regions, it will not be superfluous to insulate sewage ventilation.
Heating can be supplied from the boiler room or central hot water mains. The task will be to ensure normal temperature conditions in the rooms where the riser passes. In the attic you will have to insulate the pipe with special materials - a mineral wool winding is optimal.
Organization of ventilation output
A direct exit of the channel to the outside is carried out using a ventilation fungus. This device, which also works on the principle of a valve, but is already located on the roof surface. That is, it will be necessary to provide for a hole in the ramp and roofing. Mounted ventilation of the sewerage on the roof with the help of complete fasteners on a carrier basis. On the metal tile or profiled sheet, special holes are made for the screws on which the nozzle with a round niche is attached. A ventilation mushroom is installed in it, which is fixed under the roof with clamping joints and clamps on the back side, and immediately sealed with holes with sealant.
Ensuring safe operation of the system
Even at the design stage, you should consider the possibility of free access to all technological and functional nodes of the ventilation duct. Connection points, mounts, transition sections and working equipment must be open for quick repair. Seal failure is the most dangerous occurrence during the operation of such systems. The discharge of sewage gases into the living quarters is hazardous to health, therefore the malfunction should be fixed as soon as possible.
About once every six months, a regular diagnostics of the ventilation system of the sewage system is carried out, in which the technical condition of the communications from the lower connection point to the outlet to the outside is evaluated. For complex and productive systems that work with large volumes, it is desirable to install climate control. Sensors for monitoring the air environment in places where the fan pipe passes are also connected to it.
General ventilation tips
In the process of developing the project and carrying out installation operations, one should remember the following recommendations of specialists who will help you choose the right strategy for organizing the ventilation duct for sewage:
- A hood over the roof in the form of a mushroom is at least 1 m high.
- If the sewage system has long intra-house wiring, then it is better to install two risers at different points - this will allow to unload the duct system.
- The inclusion of sewer ventilation in the shaft of the main duct system can only be done provided that the duct runs on exhaust without pressure, and a group of valves will be used in front of the joint.
- The hood on the chimney is not necessary, because due to the warm drains it will accumulate condensate in the winter.
- It is forbidden to mount the outlet pipes under the overhangs and cornices, as they can be damaged by outgoing precipitation.
Conclusion
There are many options for designing an air circulation system in a sewer system. The most common configuration, including a fan pipe riser, but you can do without it. For example, vertical ventilation of the sewage system in a private household is not required if there is a swimming pool or communications that provide a one-time drainage of water with the closure of the main drain. In this case, it is desirable to provide a bathroom with a kitchen with aeration and disinfecting systems with the effect of microventilation. Also, do not forget about the final collection of waste. The intensity of their reception will largely determine the parameters of the optimal ventilation system - in particular, its performance and throughput.