A person should be comfortable in any room: residential, work, recreation area, etc. Air is one of the main components of a favorable microclimate. Fresh and clean, without harmful impurities – these are the main qualities that it should possess. Only a good ventilation system can provide such characteristics through proper ventilation. Both supply and exhaust ventilation must function fully. Only their well-coordinated work will give the best possible result.
Natural exhaust ventilation
Air exchange in rooms equipped with this type of ventilation is carried out strictly according to the laws of physics. The speed of wind gusts, the amplitude of external and internal temperatures, the amplitude of pressure – the main engines of the air circulation process. Full dependence on weather conditions – its big drawback. In the summer, when the temperature difference inside and outside the building is almost zero, the air exchange stops. And in the winter, on the contrary: the amplitude of temperatures is large, the cold air flows well from the street, and the process of its heating occurs due to the internal heating system. Energy costs are very large – thermal energy is spent on heating the outside air. Increase the efficiency of the air exchange system can open vents and transom, the gaps in the window frames, the gaps between the floor and the door. In residential apartment buildings, natural ventilation exhaust ducts are equipped in the kitchen and bathroom. The big disadvantage is that this type of ventilation control cannot be controlled.
Natural ventilation has a lot of positive qualities, but due attention should be paid to its disadvantages, as they can create problems in further operation. Arrangement of such a system should be extremely high quality and thoughtful, adjust or “tweak” something in the course of its work will not work.
The device of a natural ventilation system consists of internal ducts, horizontal ducts and an exhaust shaft. Strengthening the exhaust air from the premises in two ways: by installing the inlet duct of the exhaust ventilation fan or by installing a special nozzle – deflector. This is a device with the help of which the existing traction in the exhaust ventilation ducts is created or increased. It is installed on the roof, at the exit of the ventilation shaft. Such a device increases the air intake by rotating the integrated turbine. The main driving force behind his work is the wind. In the absence of wind deflector helps to avoid the appearance of reverse thrust. Competent selection of such parts will provide an opportunity to get a noticeable increase in air flow by 20%.
There are several types of deflectors:
- with a flat lid – the most simple in execution. Very often skillful owners make it themselves;
- with a removable lid – most often used for chimney channels. The ability to remove the cover makes the cleaning process very easy;
- with a gable cover – this type of nozzle very well protects the ventilation ducts from precipitation (snow, rain);
- spherical shape – well suited for any exterior. Not just beautifully fit, but even decorate it.
Most often, the deflector is used in ventilation systems with a natural type of inducement, but it can reinforce a system with a forcedly designed induction.
Installation of exhaust ventilation is fairly simple. First, the lower cylinder is screwed with bolts and nuts to the air vent. Next, attach the diffuser, reverse cone and cap.
Important! Experts recommend installing deflector 1.5 – 2 m above the roof. In this way, thrust is greatly increased.
A separate view is the smoke deflector. It is installed at the exit of the smoke channel. Exhaust smoke ventilation is increasingly in demand in industries where there is a risk of fire. Such a system plays an important role in the onset of a fire, evacuating harmful carbon monoxide and smoke. For residential premises, it is less relevant and is rarely used in them.
Installation of any kind of ventilation is a rather laborious process. Only trained professionals can properly approach this issue.
Always start with the calculation of exhaust ventilation. To do this, you need to know how much air must be forced out of the room. There are state and sanitary-hygienic norms governing regulations in this area.
Supply and exhaust ventilation. Types and purpose of ventilation systems. Calculation and design of ventilation systems. Installation and maintenance of equipment.
An experienced engineer always knows where to find the necessary information. Using reference information and tables, he will calculate the amount of circulating air and what parameters it should have. The exhaust ventilation system of a residential building is calculated taking into account these rules. For this, several basic methods are used: by area of premises, by multiplicities and by SNiP.
Calculations on the floor space – the easiest way. It is based on the fact that according to the rules it is necessary to supply 3 cubic meters of air per 1 square meter of space. The number of people is not taken into account.
According to sanitary and hygienic norms, 60 cubic meters of air are required per person, which is permanently in the building, and 20 cubic meters of air per person, which is temporary. To enter the room should the amount of air equal to the compulsory discharge.
The calculation of multiplicities is considered the most laborious. The air exchange rate is a number indicating how many times the air is completely replaced within one hour. There are tables with the multiplicities given in them specifically for each room. Using special formulas, calculations are made that directly depend on these table values and the volume of the room.
Natural ventilation has the simplest scheme. Such a system consists of an air intake, grille, hood and air vent.
The scheme of mechanical ventilation includes more elements: the air intake, grilles, hood and air vent, fan, noise insulation and ventilation ducts. The control of such a device occurs with the help of electronics, which completely controls the process of removal of forced air masses.
After all calculations have been made and the necessary components have been selected, proceed directly to the installation of exhaust ventilation. Local exhaust ventilation is very relevant for residential premises. Most people use hoods in the kitchen. Its installation can be made both by a specialist and independently. Forced exhaust air, steam and odors are discharged to the outside through ducts. Managing exhaust ventilation in the kitchen is carried out manually: it turns on and off as needed.
Local exhaust ventilation with their own hands can be easily mounted using flexible ducts. Installation of the hood in the kitchen is made directly above the stove. The best option would be to bring the outlet out. In the opposite case, leading the pipe into the ventilation channels of natural ventilation, you can get the effect of reverse thrust. Clearly following the instructions, having prepared the necessary materials and tools in advance, everyone can easily install an excellent exhaust system in the kitchen.
Important! The working surface of the hood must be greater than the width of the plate. Couples should not go beyond it.
In many rooms, single exhaust ventilation is often not enough. The massive use of metal-plastic windows and doors with a tight sealant leads to blocking the flow of fresh air.
This problem can be solved by installing forced-air ventilation. With its help, they provide a solution to two important issues at once: the supply of clean air and the withdrawal of the already exhausted.
The natural ventilation system, which is most often used in residential buildings, is in fact the simplest supply and exhaust ventilation. But, as already mentioned, managing it is almost impossible. Therefore, an effective solution will be the device of the supply and exhaust ventilation system of a mechanical type. It will force the supply and discharge of air, ensure its movement in both directions. The installation of such a system is also very beneficial because you can optionally add additional components that will significantly improve the air quality in the room. Such components can be a device for humidifying the incoming air or its heating. Additional heating is called recuperation and significantly increases the energy efficiency of residential premises.
Calculation of the supply and exhaust ventilation is the first step to its installation. It depends on how the system will function in the future. First, you need to determine the purpose of the premises (residential, industrial, warehouse, etc.), its total area and the maximum number of people in it. According to this data and the multiplicity indices taken from regulatory tables, the necessary calculations are made. After that, a scheme of supply and exhaust ventilation is developed.
The scheme of supply and exhaust ventilation may include the following components:
- duct – channel for the distribution of air masses;
- fan – a device that forcibly supplies or removes air;
- air intake grille – its installation ensures that a foreign object or small animal never enters the system;
- air intakes and air distributors – responsible for managing the continuous circulation of air and its distribution;
- air valve – does not allow air to enter the room when the entire device is turned off;
- silencers – control of the noise level generated by the fan;
- filter – used for cleaning from dust and very small substances;
- air heater – a device for heating the air in winter;
- heat exchanger is a special device for energy saving;
- control system – controls the operation of all components, turns the installation on and off, reports failures.
Arrangement of supply and exhaust ventilation begins with the routing of ducts inside the premises. In the future, install additional structural elements on the outer side of the building. The last is mounted duct outlet. A device of this type must comply with the rule: air circulation must take place in the direction from the living rooms to the bathroom and kitchen.
Helpful advice! Supply and exhaust ventilation with their own hands is installed without too much difficulty. Experts advise to pay special attention to the fasteners of pipes, as they are under pressure from the air flow. With a weak fastening connections may diverge.
Natural ventilation is quite energy intensive during the cold season. It is impossible to control the incoming air masses, and the task of heating them falls on the heating systems.
The mechanical ventilation device forcibly takes in air from the street. In winter, its temperature will be much lower than room temperature. In the same way, the heating system will constantly work on heating the incoming flow, as in the case of natural ventilation. And again the energy costs are very high.
To solve the problem, the leading manufacturers in this area propose to use forced-air ventilation with heat recovery. A recuperator is a device that carries out heat exchange between warm (forcibly discharged) and cold (forcibly supplied) air flows. Its design provides only heat exchange, preventing various odors or moisture from penetrating back. Recuperator management is quite simple. The design is on – heat exchange is carried out, off – there is no heat exchange. The system with recovery is very energy efficient and, despite its high cost, quickly pays off. Forced-air and exhaust installation with recovery is most in demand among consumers today.
Efficient exhaust ventilation is very important for buildings of any purpose. A less productive natural system has a simpler device. Strengthen its capabilities will help the deflector. Installation of equipment of mechanical type will be technically more difficult option. But the simple management of such a system and the ability to adjust the parameters of the incoming air will have a positive impact on the microclimate of the room.
Local exhaust ventilation in the kitchen clearly shows everyone the importance of such equipment. All unnecessary odors, fumes, vapors are forcibly removed by exhaust ventilation. This always has a positive effect on the quality of the atmosphere, not only in the kitchen, but also throughout the room as a whole.
Systems with recuperation are very practical in terms of reducing energy costs. And, if you thoroughly delve into the description of their device, it is possible to make a recuperator with your own hands in order to significantly improve the quality of the ventilation system.