Unfortunately, in our cities it is not enough to open the windows and open the doors to receive an influx of fresh air – along with it heat or frost, dust and the smell of exhaust gases, noise, insects and city smog penetrate into the housing. Exhaust ducts in apartment buildings often have insufficient cross-section and are rarely serviced, there is practically no natural draft, so smells from the kitchen and bathrooms spread throughout the house …
Forced ventilation is the only way to quickly remove stale air, regardless of the size of the housing. With supply and exhaust ventilation, cleaned, warmed up, or chilled, fresh air will enter the room. Exhaust dirty air is removed directly from the place of distribution of odors.
A properly selected and installed ventilation system will allow you to normalize the air in the room and get rid of problems such as mold as well as fogging of mirrors in rooms where the humidity is too high.
The ventilation is formed not only through bulky supply and ventilation units with a recuperator, and the estimate is not always frighteningly large. Small, but attractive and efficient exhaust fans can be used for high-quality room ventilation, fresh air can be supplied with special air conditioners, supply valves and compact devices of the supply type.
Types of room ventilation systems
- Natural ventilation
- Mechanical ventilation (forced)
With natural ventilation, the exhaust air leaves through ventilation ducts built into the wall, and fresh air flows through the windows and the gaps in the doors. This type of ventilation is present in all apartment buildings, but the quality of air removal depends on the outdoor temperature (the warmer, the worse the draft), wind speed and condition of the house ventilation duct. Mechanical ventilation of the apartment is always designed separately. Exhaust fans in the bathroom, toilet and kitchen hood above the stove are a necessary minimum of devices that the apartment owners install during the repair.
The main task of mechanical ventilation of the exhaust type in apartments is the elimination of unpleasant odors (bathroom, toilet) and odors from the kitchen, as well as reducing the humidity level in the room. For this, axial and centrifugal exhaust fans are used. When choosing them, you can not do without consulting with specialists, because the performance of the fans should not exceed the capabilities of the house ventilation duct, and the type of automation for turning on and off should be convenient for the owner of the apartment.
To supply clean air to the room, you can use both budgetary means – inlet valves for plastic windows, valves for fitting into a wall or window, window and wall inlet fans, and inlet ventilation units that can clean and heat incoming air efficiently.
Features of supply and exhaust ventilation of the room
The ventilation system of the supply and exhaust type is most often designed in apartments with a large area and can serve both one room and all rooms. Such ventilation combines the forced supply of purified street air and the extraction of exhaust air outside with the help of a supply and exhaust unit located outside the wall of the house or on the balcony. The ventilation unit for the apartment can have a different number of functions, including heating (using a heater or recuperator) and humidification. The most economical units of this type interact with the recuperator, therefore they are able to utilize the heat of the exhaust air and give it to the incoming air (90% less energy will be spent on heating!).
A properly designed kitchen ventilation system is designed to prevent the spread of excess heat, odors, products of combustion of food, gases and steam. The ventilation of the kitchen should provide air exchange at a minimum level of 90 m³ / h, the optimal level –110-150 m³ / h. The level of air exchange is determined based on the type of stove used in the kitchen.
In any apartment building in the kitchen, natural exhaust ventilation is provided – an exhaust opening is provided close to the ceiling. Natural ventilation carries out air removal into the ventilation duct with a section of 130×130 mm (ø140 mm) with a throughput of up to 150-180 m³ / h. The effectiveness of its operation depends on many factors: the ventilation duct pollution, outdoor temperature (the hotter the exhaust hood works worse), wind. We also note that the ventilation in the apartment is also natural, but unorganized, therefore, for the influx of fresh air it is necessary to ensure its flow, for example, through an open window, window, doors or by means of infiltration.
Due to the low productivity and problems with the flow of air, natural exhaust ventilation does not cope with the task. In addition to it, mechanical exhaust ventilation of the kitchen is installed. For example, it can be an exhaust hood in the kitchen (exhaust hood) that can “intercept” odors and grease until they spread throughout the room. It can also be used:
- Kitchen exhaust fan
- Household duct fan
If the door-windows are closed, a vacuum may occur during the operation of mechanical exhaust ventilation, in the absence of air flow, the efficiency of exhaust ventilation deteriorates, and in some cases ceases to work: due to the back draft, the exhaust ducts begin to work on the inflow. To avoid this phenomenon, several types of devices are used to ensure the inflow:
- Supply valves: installed on a window or in a wall (hole diameter 100-125 mm), operate without power supply. The maximum inflow is up to 40 m³ / h.
- Ventilators (breathers): devices with the possibility of heating the air, equipped with a filter and a fan. Ventilators installed in a through (ø100-125 mm) wall opening are capable of creating an inflow in the range of 35-120 m³ / h.
- Supply and exhaust ventilation units: devices with fans and a duct system that are installed in the sub ceiling space of auxiliary rooms (if the ceilings are suspended), as well as on glazed balconies or loggias. Such plants utilize the heat of the exhaust air using recuperators and are able to heat the supply air masses.
The least costly and not demanding maintenance are supply and supply and exhaust ventilators (several such devices are installed in the apartment). It is rational to use the units not only in large apartments, for high-quality air exchange, ventilators install in each room. The most profitable way to get a large volume of clean air without allergens, midges and dust – ventilators for the kitchen.
The standard ventilation of the apartment provides only exhaust ventilation of a natural type through wall grilles installed on the ceiling in bathrooms (bathroom, toilet) and in the kitchen. Thus, a vacuum is created, and to normalize the pressure through the door (overflow) grate, door gaps and a window (if any), an air inflow from other rooms is carried out.
The ventilation of the bathroom should provide a consumption of removed air of at least 50 m³ / h (optimal parameters are at the level of 54-72 m³ / h). However, a natural exhaust ventilation system is rarely able to provide the necessary level of air exchange. It’s very simple to check the natural exhaust of the bathroom:
- Fire lighters. Bring the lighter to the ventilation grill: if there is a flame tilt towards the grill, the exhaust system works.
- Piece of paper. Bring a sheet of paper to the grate: if it is pressed against the ventilation grate, the exhaust system works.
But if at the same time fungus and mold develops in the bathroom, if drops of condensation accumulate on the walls, if you feel stagnant, ripe odors – these are signs that you can’t do without an exhaust fan for the bathroom!
The installation of an exhaust fan in combination with the use of a door ventilation grille (or the organization of a ventilation gap under the door) will solve all of the above problems. As a result, unpleasant odors and excess moisture will be immediately removed from the bathroom, the causes of mold and fungus will disappear, the mirror will stop fogging. In addition, in all modern bathroom fans there is a check valve, thanks to which, even with the fan turned off, no smells from neighbors will come into your apartment!
Hood for the bathroom
It is very important to preserve the beauty of the finish in the bathroom, so the fan should be not only effective, but also aesthetic. In 90% of cases, for the organization of the hood in the bathroom, it is enough to install a household axial fan with a check valve. Its placement is made directly into the ventilation duct hole, instead of the grill, so it can have an installation diameter of 100, 120 or 150 mm. The performance of axial-type household fans is 50-220 m³ / h, and the design options are the sea!
If you need a fan for flush mounting to the ceiling or wall at some distance from the ventilation duct (only the front panel is visible), you can install a centrifugal fan with a built-in housing. The productivity of such devices is 60-300 m³ / h, the noise level is slightly higher than that of axial models. An air duct is used, which is covertly laid to the ventilation duct, such a fan will also not spoil the interior design.
The fan for the bathroom can be switched on in different ways: from a separate key, together with the light, at a certain level of humidity. Turning on and off may be slowed down by a timer. Also, the device may have several speeds, and its operation may be interval.
Often, for better control of moisture in the bathroom, fans with a humidity sensor are used. The device itself understands when it needs to work, and when not.
Most often, a toilet is meant as a toilet, so there are such concepts as a combined or separate bathroom. However, in both cases, the ventilation of the apartment should be designed so that unpleasant odors are immediately displayed outside the apartment, and not spread to other rooms, confusing guests and family members.
Unfortunately, exhaust (with a natural impulse) ventilation in our homes is not enough to organize optimal air exchange. According to DBN V.2.5-67: 2013, the performance of the hood in the toilet should be at least 50 m³ / h, and its optimal value should be 50-80 m³ / h. In the case of natural ventilation, we observe increased humidity, the development of mold and fungus in the corners, and condensation.
Only the installation of an exhaust fan will help get rid of unpleasant odors and normalize the level of humidity in the toilet. Starting to choose a fan for the bathroom, we see three options:
- Axial fans
- Centrifugal fans (built-in and laid on case)
- Channel fans
The widest choice in terms of design and functions is presented among the axial models. And for good reason – these are the most popular and popular options for toilets, consuming a minimum of electricity, low noise and compact. True, they are able to overcome only a little pressure, so on the first floors of high-rise buildings they may not be very effective. Axial models differ in mounting diameter (100, 120 and 150 mm) and performance – from 45 to 220 m³ / h. The ventilation of the bathroom with the help of an axial fan can even be organized independently – the device is installed in the ventilation duct opening, and complexity can arise only with an electrical connection.
Centrifugal fans have a case up to 10 cm thick, inside of which a “snail” is installed. There are overhead (all thickness in sight) and built-in (the body is hidden in a suspended ceiling or wall) models. An air duct is hidden from such a fan to the ventilation duct shaft. Based on aesthetic considerations, it is better to use built-in models for apartment bathrooms. Their performance may be higher than axial models, but they are able to overcome high pressure in the ventilation ducts of buildings.
For a more efficient exhaust and economical exhaust, we recommend installing fans with a shutdown timer that stop working after a period of time that you set.
Channel models are very effective and efficient, but are rarely used in standard apartments. The reason is the need to lay ducts between the rooms, which is possible only in apartments with a free layout and new buildings.
Calculation of fan performance
According to DBN 2.2-15-2005 “Residential buildings”, the exhaust from the bathroom should be at least 25 m³ / h, but this may not be enough. When selecting an exhaust fan, you must take into account the features of the bathroom (shower, jacuzzi, bathtub).
In order to calculate the fan performance for a bathroom, it is necessary to calculate the volume of the room. To do this, multiply the area (sq. M) by the height of the ceiling (m). Multiply the result by 5-10 (air exchange rates). For example, for a toilet of 2.5×1.5 m and a height of 2.5 m, a device with a capacity of 47-94 m³ / h is required.
The size of dressing rooms in apartments can be large or small. Often they consist of a fenced corner in the room and do not have windows. Do I need to ventilate them? In accordance with DBN B.2.2-15-2005 “Residential buildings”, if the size of the dressing room allows you to iron or clean clothes, in this room it is necessary to provide an extract with 1.5-fold air exchange. Therefore, if by the dressing room you mean not just a large closet, but a separate space with cabinets in which you can turn around, turn around or iron clothes, the ventilation system in the closet must be!
Things on the shelves and hangers of the cabinets appear after washing and, if necessary, ironing. Residual moisture accumulated in the fibers of the fabric will tend to evaporate. If the air exchange is not enough for this, the moisture stagnates, a “scent” of beauty arises, and the air becomes stale. Due to the fact that the wardrobe rooms are often not heated and one of the walls is “cold”, moisture condensation and the development of fungus and mold are possible. Smells in the dressing rooms can also be the source of winter clothes made of leather and fur, as well as shoes.
The ventilation of the dressing room will protect the linen and clothes stored in it from spoilage and an unpleasant odor, and prevent high air humidity and the formation of mold.
How is ventilation in the dressing room organized?
Due to the fact that the layout of many apartments does not include such a room as a dressing room, it is not equipped with an exhaust duct for natural ventilation. As a rule, the ventilation of the apartment provides air removal only through the kitchen hood and the transfer grill of the bathroom. Therefore, if the natural influx into the dressing room can still be arranged through the lower gap of the door, ventilation holes in it or wall valves, then the hood should in any case be forced.
Forced ventilation in the dressing room of an apartment can be organized in several ways:
- By means of air ducts of the supply and exhaust ventilation system.
- Using an axial or centrifugal exhaust fan for the dressing room and duct connected to the room.
- Using a duct fan and ducts.
- Due to the axial fan with an interval switch connected to a horizontally located duct.
- By means of a breather (ventilator) installed in the outer wall and a supply valve placed on top of the opposite wall, if one of the walls of the dressing room is external.
In the first four cases, air ducts are laid at the stage of repair during the arrangement of ducts of multilevel ceilings, otherwise they will remain in sight and ruin the interior design. In case of installation of a ventilator, which is installed in a through hole with a diameter of 125-150 mm, the facade of the building will deteriorate, so this option is not suitable for every apartment.
Stale air, its excess humidity, the appearance of unpleasant odors, “sweating” windows and mold on walls and closets bordering the street, all this is just an incomplete list of problems that bedroom ventilation should solve.
Of course, the ventilation of the apartment provides for the presence of ventilation ducts of natural exhaust ventilation, but what about in the summer, when the efficiency of natural draft is minimal, and dust flies into the open windows, street noise and heat penetrate? Only mechanical ventilation of the bedroom will help you, the main thing is to choose the best option for solving your specific problem.
Air exchange rates for bedrooms
For each person, an air exchange of at least 30 m³ / h is required. In this case, in accordance with DBN, the supply ventilation in the bedroom should provide a single air exchange in the room. The flow of air from adjacent rooms to the bedroom is undesirable – odors, bacteria and carbon dioxide move along with the airflow.
Ways to organize ventilation in the bedroom
Many citizens install a powerful exhaust fan in the bedroom. As a result, we get either a draft or an influx of air from the kitchen or bathroom with the attendant “aromas”. The ideal solution for bedrooms is to either organize only an influx, or use a precisely calculated supply and exhaust system.
The DBN says that bedrooms need an influx of fresh air that must come in through the windows. It also notes that when using sealed windows and windows without vents, it is necessary to install built-in ventilators in the window leaf. This advice is rational, especially since on sale you can find automatic hygro-adjustable supply valves that work silently, without the use of electricity and can be installed on the window frame even after completion of construction work. Their productivity is 5-50 m³ / h.
The influx in the bedroom can also be organized using breathers (ventilators with electric fans), which are mounted in the outer wall through a through hole 125-150 mm. Choose ventilators with a filter, the function of sound attenuation and air heating. Similar to breathers, in the bedrooms can be installed wall-mounted inlet valves with flow control that do not require an electrical connection.
If the bedroom has no windows and there is no external wall, the ventilation in the bedroom can be organized with the help of a ventilation unit, supplying heated air through the duct laid to the bedroom. Such installations are mounted on a balcony or loggia.
In a more expensive version, you can use a ventilation unit that serves the entire apartment and heats the influx due to recovery. This solution is more expensive in the organization, but as efficient as possible.
Ventilation of the living room
In the living room we spend evenings, meet guests, organize feasts and just relax after work. Therefore, the ventilation of the apartment should be equipped in such a way that there is enough fresh air in the living room, regardless of the number of people present in this room. With a large concentration of guests, at least 70-150 m³ / h of supply air is required! At the same time, the living room should not be cold during the cold periods of the year.
Often the living room in the apartment is connected to the kitchen area or loggia. To minimize the spread of odors, the supply of fresh air masses should be carried out so that the exhaust air is displaced from the living room into the kitchen, and not vice versa.
Living room ventilation equipment
In apartments, the ventilation of the living room is individually designed. One of the available methods for arranging the ventilation system is the use of wall breathers (ventilators), which are installed in the through hole prepared in the area of the heating radiator. However, it should be remembered: the influx of fresh air with this solution will not exceed 40 m³ / h.
Window ventilators, or valves, can provide greater productivity due to quantity. Such devices will be effective with a significant temperature difference inside and outside the apartment, and a pressure difference of at least 10 Pa.
The hood in both cases is natural, carried out in the direction of the kitchen and bathrooms. In the presence of multi-level ceilings or wall ducts, the best choice for the living room is the installation of ventilation units of the supply and supply and exhaust type.
Ventilation units form an optimal volume of fresh air, provide for its cleaning and heating. In the first case, only a tributary is sent to the living room, in the second – at one end of the room an influx is formed, and in the opposite a hood.
Ventilation equipment, including an influx heater, a muffler and a filter, is located on the loggia or balcony in the apartment. All ducts are hidden behind a suspended ceiling, and only ceiling ventilation grilles are visible.
If the living room does not function as a bedroom, at night the forced ventilation of the living room may be limited so that electricity is not wasted. To do this, VAV controllers are used to reduce or disable the ventilation of the living room at night.