2023 Author: Philip Bishop | [email protected]. Last modified: 2023-05-24 22:24
- The need for ventilation in the house
- Natural ventilation efficiency
- Organization of ventilation of the apartment
- Types of ventilation
- Improving natural ventilation
- The use of supply units
- The most efficient ventilation system
- Ventilation device stages
- Kitchen ventilation
- Checking the ventilation system
Any modern housing, including apartment buildings, is built taking into account the minimization of heat loss in it. With the use of high-quality thermal insulation materials and appropriate construction technologies, the problem is solved without much difficulty. But at the same time, a somewhat unexpected problem arises: after all, a well-insulated room turns out to be practically airtight and unventilated! And comfortable living in such a room without a properly organized ventilation system becomes simply impossible.
The need for ventilation in the house
The rules for organizing air exchange in apartment buildings are established by the corresponding sections of the SNiP. According to these rules, the ventilation system must ensure uninterrupted air replacement in all service and utility rooms of the building - bathrooms, toilets, combined bathrooms and kitchens.
This is due not only to the high humidity of the atmosphere in these rooms, but also to the almost constant presence of a person in them, leading to the pollution of the air masses - no matter how clean this person is. Air pollution and a high concentration of moisture in it in the absence of air exchange quickly lead to very unpleasant consequences:
- the formation of condensation in the windows and their fogging;
- the appearance of dampness and mold;
- the spread of an unpleasant musty smell;
- damage and destruction of all objects in contact with such an atmosphere;
- the rapid multiplication of pathogens;
- poor health of people in the room.
Natural ventilation efficiency
According to the same SNiPs, ventilation in apartments should be carried out in a natural, supply and exhaust way: in place of the heated air leaving through the ventilation ducts through the leaks in door and window openings, open vents and other "natural openings" of the building, street fresh air enters. Although in modern metal doors and plastic windows such leaks should not be in principle - if they are available, the product is considered a marriage …
Opening windows can help a little in the warm season, but in winter it is simply inappropriate - too cold air is "pulled" from the street instead of comfortable warm air. The second drawback of an open window is dust and even outright dirt getting into the room.
On the top floor of the building, the efficiency of natural supply and exhaust ventilation is reduced to the very minimum. This is explained by the fact that for its normal operation, the height of the ventilation duct (in fact, the exhaust pipe) above the ventilation hole must be at least 2 meters; the condition for the last floor is difficult to fulfill, especially in the absence of an attic space.
The development of energy saving technologies (including heat preservation) has led to a somewhat paradoxical situation: without the use of additional draft-enhancing devices and devices, supply and exhaust ventilation of a natural type in modern apartments has become absolutely ineffective!
Organization of ventilation of the apartment
The specific type of ventilation system is selected based on the existing air exchange rates, depending on the purpose of the ventilated room, its volume and the number of inhabitants. To date, the following basic standards have been established:
- for each square meter of housing, at least 3 "air" cubic meters per hour must flow;
- for one adult you need at least 30 cubic meters of fresh air every hour;
- for kitchens with an electric stove, the rate doubles (60 cubic meters / h), when using gas stoves - three times;
- for a bathroom, it is enough to replace 25 cubic meters of air per hour;
- in toilets and combined toilets the volume of the replaced atmosphere should be greater - about 50 "cubes" per hour.
Types of ventilation
By and large, there are only two ventilation methods - natural and forced.
In the first case, a draft is used to circulate air masses, which occurs naturally due to the difference in temperatures outside and inside the room. At the same time, air moves from the room to the street.
Forced ventilation is created artificially, by using electric or mechanical fans - in this case, the direction of air movement can be any, both from the house to the street (exhaust ventilation), and from the street to the room (supply ventilation). In addition, these two ventilation systems - extract and supply - are relatively easy to combine into a combined unit. Find out about new innovations in ventilation systems.
Improving natural ventilation
The simplest ventilation method that does not require financial costs and construction work is to ventilate apartments. In this case, the air entering through the open vents and the slots or gaps in the door or window blocks is discharged through the ventilation ducts in the walls of a multi-storey building.
However, this method is far from always acceptable - especially in modern, practically sealed dwellings, in which "unauthorized" air from the street into the house is excluded. The way out is to install (cut-in) special supply valves with an adjustable opening diameter and a sound-reflecting visor into the walls.
Such valves are mounted at the level of heating radiators and, due to their modest (about 10 cm in diameter) sizes, fit perfectly into any interior. It is recommended to equip them with special heaters or at least install them near heating devices - this will ensure at least partial heating of cold air coming from the street.
Unfortunately, for all its simplicity and speed of installation, such a ventilation system has one significant drawback: its efficiency almost entirely depends on the efficiency of the existing ventilation ducts. In the cold season, when the difference between cold outside and warm indoor air is several tens of degrees, such a system provides quite high-quality air exchange; in summer, the degree of its performance is minimal …
In addition, with natural ventilation, it is impossible to control and regulate the volume of transported air. As a result, it becomes very difficult or even unrealistic to control the microclimate in the apartment.
The use of supply units
If it is impossible to remove air naturally, it is necessary to pump it out mechanically, using duct fans built into the ventilation ducts. However, in this case, reliable control of the inflow volume is not possible. And this may well lead to a situation where there is not enough fresh air in the apartment …
In such cases, it is necessary to install air handling units mounted in the main wall of the building and consisting of the following units:
- fan in the case;
- replaceable filter;
- devices for heating incoming air;
- shut-off valve.
Such a device has a design that excludes the formation of an increased level of noise during operation, and is mounted in a hole punched in the wall of the building of the corresponding diameter. After connecting to the power supply, the air handling unit begins to forcibly supply fresh air to the serviced apartment, while the old one is naturally or “ventilated” drawn through the ventilation ducts. At the same time, in order to ensure the unhindered movement of atmospheric flows, the lower zones of the interior doors are made lattice or at least cut by 1 … 2 cm.
The device in the apartment of the forced ventilation system makes it possible to ensure year-round supply of warm (if there is a heating device in the system) fresh air into the room, which excludes the formation of condensation and the development of mold in the house. But the problem of controlling the volume of exhaust air discharged through the ventilation ducts at the household level, with limited financial capabilities, is practically unavoidable - and with poor draft in the ventilation ducts, zones with a stagnant, "stale" atmosphere may form in the room.
The most efficient ventilation system
The ventilation system, free from all the above drawbacks, is a forced recuperative supply and exhaust "exhaust", which provides a constant supply of outdoor fresh air to the room and the corresponding volume of exhaust air masses. Moreover, when using additional elements, the air passing through the system is also subjected to multi-stage cleaning.
Forced ventilation with recuperation is a rather complicated system in design and installation. It consists of a large number of nodes and elements, the main of which are:
- air ducts - pipes connected into a network through which the forced movement of air masses is carried out;
- fans that ensure the movement of air flows;
- air intakes;
- air valves that prevent the penetration of masses of street air into the room when the ventilation system is off;
- filter elements;
- heating air heaters;
- noise suppression devices;
- ventilation and air intake grilles;
- elements of automatic protection against overheating;
- control systems and sensors and regulators that determine the algorithm of its operation …
The principle of energy recovery (recovery) used in the operation of such a system allows, when the air coming from the street is heated by the air masses, to reduce the consumption of energy consumed in winter by 70 … 80%!
Ventilation device stages
The design of a ventilation system begins with a comprehensive analysis of the feasibility and necessity of its use in the apartment. At the same time, the efficiency of the existing system is determined, the possibility of its improvement or the need for a complete transfer to "compulsion", the possibility of installing additional ventilation ducts is checked.
The calculation of the optimal air exchange system is done for each room separately; based on all the data received, the type of ventilation system for the apartment is selected. In this case, a ventilation diagram is drawn up, which indicates all the main technical parameters of the designed system:
- air duct tracing;
- exact lengths and sections of air ducts;
- location of all involved ventilation units;
- the exact locations of the used shut-off and control devices;
- overall dimensions of installations;
- name and amount of required materials.
In order for the result to be guaranteed, all work on both the design and installation of the ventilation system should be done by experienced specialists - only then the air exchange in the apartment will be effective, and the microclimate will not pose a danger to human health!
The ventilation device in the kitchen is complicated by the need not only to reduce air humidity, but also to clean it from various odors. To some extent, kitchen hoods installed above the stove cope with these tasks - but only to a very small extent …
Organization by means of a forced ventilation hood is ineffective - the fan installed in this household appliance is low-power and is able to "pump" a very small volume of air through itself. The hood is enough to remove steam directly above the stove - but that's all. Even recirculation-type devices do not save the day, in which the "trapped" air is cleaned through a filter system and thrown back into the room - the performance of such hoods is too low for the entire volume of the kitchen.
Effective ventilation in kitchens is possible only by creating a complete ventilation system. It should be borne in mind that the throughput of ventilation ducts built into the walls of apartment buildings, due to their small (13x13 cm) section, is low and does not exceed 300 cubic meters. m per hour (usually it barely reaches 160 cubic meters / hour …). Self-installation of too powerful "forced" will disrupt the operation of the ventilation system of the entire apartment building …
The only way to independently improve the operation of the natural air exhaust system from the kitchen is to install a low-power duct fan into the existing ventilation duct. In many cases, this allows you to create a completely acceptable microclimate in the room with minimal financial and labor costs.
Checking the ventilation system
A rough but quick test of the effectiveness of the ventilation in the apartment can be done with a simple piece of paper or a lit match. If you open one of the vents available in the apartment (any) and bring paper to the opening of the ventilation duct, with more or less efficient ventilation, it should "stick" to the grate. The flame of the match should be drawn into the channel.
It is possible to more accurately determine the performance of ventilation using an anemometer, a device designed to determine the speed of air flow. On the basis of its readings and knowing the cross-section of the ventilation duct, it is possible to calculate the volume of air passing through the duct in one hour. But, unfortunately, the availability of this method is much lower than the previous one.