How natural ventilation works
Natural ventilation in our apartments is designed in such a way that air flows can freely flow from one room to another, moving from an area of high pressure to an area of lower pressure, i.e. from heat to cold. One air comes out, and another comes in its place. This is physics or the law of nature, and we are powerless against it.
With the advent of beautiful and airtight plastic windows in our homes, as well as metal doors with high-quality seals, the supply air cannot enter the apartments and the natural movement of air or air exchange stops. There is no more fresh air in the dwellings, the apartment is stuffy and high humidity. And here our man comes up with an additional problem for himself - this is the installation of exhaust fans and "umbrellas" over the stoves.
The basic principles of organizing ventilation in the kitchen
Modern residential buildings are provided with a built-in ventilation system. It works due to the difference in densities of warm air in the room and cold air inside. For the ventilation of an ordinary living space, a well-designed and properly built natural exhaust is quite enough, but in conditions of active cooking, its efficiency will be low. To protect yourself from such problems, you need to solve two key problems:
- install an exhaust ventilation system in the kitchen;
- provide a steady supply of fresh air.
There is a very important principle in medicine - do no harm. The same applies to repair and construction work. If, without understanding the design features of ventilation systems, you start reorganizing them, you can get a diametrically opposite result.
Very often, tenants of apartment buildings try to expand the kitchen space by demolishing or relocating existing ventilation ducts. As a result, it may turn out that with such a reorganization it will not be possible to make a high-quality hood, and the atmosphere of the room will begin to be filled with the aromas of one's own or a neighbor's toilet. The second problem for which kitchen ventilation may not work is cheap plastic windows.
Old wooden structures did not provide complete tightness of the premises, so natural ventilation occurred through their cracks. Modern windows are able to completely block the flow of fresh air, which, of course, will reduce the cost of heating such a room, but at the same time exclude the possibility of ventilating it in the closed position.
A working exhaust vent will remove contaminated air from the kitchen, creating an area of low pressure. For this reason, air from neighboring rooms will rush into it, into which, in turn, flows from ventilation systems or a staircase will be drawn. As a result, the apartment will be filled with the aromas of common areas and neighboring apartments, which is unlikely to please anyone.
There are two main rules:
- any unauthorized intervention in the natural ventilation system can lead to its failure;
- window openings of the kitchen should be equipped with devices that provide fresh air.
Types of ventilation systems for the kitchen
Even the most perfect natural ventilation is not able to cope with the atmosphere of the kitchen, so it needs to use additional systems that can intensify air exchange. Such devices are classified according to:
- installation method;
- working principle.
Depending on which design is chosen, both the results obtained and the costs of creating an outflow of polluted air will differ. The fumes concentrated in the atmosphere of the kitchen contain a lot of grease, soot and other contaminants, which, if not removed, will settle on the furniture, quickly making it unsightly. The same threatens freshly made repairs. You can install the hood both independently, using the instructions attached to it, and with the involvement of specialists who will perform this work, taking into account the characteristics of the ventilation system of a particular house.
Differences between ventilation and exhaust systems
Many people confuse ventilation with an exhaust hood, naively believing that they are one and the same. That, by installing an exhaust dome over a stove without a fan and connecting the air duct to the regular channel of the ventilation unit, they will get two in one - both ventilation and exhaust. Will such ventilation work? Of course not.
First, the main opening of the ventilation duct is blocked by an air duct. Secondly, the dome of the hood will be located approximately at the middle of the height of the kitchen, which significantly reduces the effectiveness of natural ventilation. Thirdly, such a system without a fan is absolutely useless and is not able to cope with fumes, most of which, together with warm air, bypassing the exhaust dome, will rise to the ceiling.
There are two options that allow you to use the ventilation system and the exhaust system at the same time. Complementing each other, they will create a comfortable microclimate in the kitchen:
- Use of a circulation hood.
- Installing a flow hood with a check valve.
Natural air exchange in the kitchen of a private house
The natural ventilation of the kitchen of a private house is experiencing the same difficulties as in the apartment, and maybe even more, since a lot of mistakes are made, starting from the design process. It seems that there is a ventilation system in the house, but on closer examination it simply does not work. Next, we will consider the main mistakes in the design and installation of the ventilation system of the cottage.
- Location of ventilation grilles. By all rules, they should be at least 10 cm. from the ceiling, since warm, exhaust air must exit through them, displaced by colder - supply air. But in practice, things are not so rosy: In many kitchens, the exhaust grates are much lower, and as a result, a stagnation zone is formed that is above the grate.
- To save money, in a private house, often, neighboring rooms are equipped with one ventilation shaft. That is why air, and with it smells, can move from the kitchen to the room, and not through the ventilation shaft. From the standpoint of sanitary and hygienic standards, this is wrong.
- Another common mistake in the design of natural ventilation in a private house is the insufficient height of the ventilation pipes. Due to the small pressure difference, such ventilation may not work.
The cottage kitchen must have a natural ventilation system, but in practice, most developers do not consider this necessary and install only forced ventilation, which depends on electricity. There is no electricity, and the fans do not work, the exhaust air masses are not removed.
Very often makes the ventilation system work incorrectly, oddly enough - a fireplace. When the fuel burns, it burns oxygen and pumps air out of the ventilation ducts.
These are just the main mistakes that are made when designing the natural ventilation of a private house. But how to make ventilation in the kitchen more efficient?
Efficient do-it-yourself ventilation
If the ventilation in your house does not work or works poorly, then with some simple knowledge or following our advice, even an amateur can revive it.To do this, you need to know the principles of air flow and a few basic rules.
- The kitchen belongs to the room with intensive air exchange. According to the norms, the air exchange in this room should be no less than 90m3/hour. Translated into a more understandable language, this means that 90 cubic meters of waste air masses should be removed from your kitchen in one hour. But according to the balance equation ∑ Lpr. = ∑ Lvyt, for sufficient air exchange, an inflow of 90 m3 / h is needed.
Armed with knowledge, now to restore ventilation in the kitchen, you need to install an exhaust fan, in the ventilation duct, with a capacity of at least 90m3 / h. But we remind you that this is only if the natural exhaust air from this room does not work.
Now you need to take care of the supply air. It is possible to keep the windows open in the kitchen year-round, but we think that this is not an option. For good air exchange, you can install supply valves in the wall that faces the street. As a rule, they are mounted behind a heating radiator and the incoming cold air masses immediately heat up. The main thing is to maintain a balance between the volume of supply and exhaust air.
The ventilation system of your home, made in accordance with all the rules, will provide you with fresh and clean air, and will delight you with the absence of foreign odors and high energy efficiency.
Circulation hoods
The principle of operation of these hoods is that they do not remove polluted air from the kitchen, but due to the installed filters, they clean it from small drops of fat, moisture and odor. In fact, this is a unit for collecting fatty particles and air filtration. In this case, regular ventilation provides circulation and air change. Such a hood consists of such structural elements as:
- Frame.
- Electric fan.
- Fat catcher.
- Carbon filter.
The fan provides a constant supply and passage of air through the filters. The first filter collects and retains fatty particles, the second (fine carbon filter) neutralizes odors and moisture. Dirty filters must be replaced and are fairly easy to change. The service life of filters depends on the hood model, design and frequency of its use.
Types of suspension systems
Suspension systems are classified according to their location in the kitchen. This will depend on how and where they will be attached. Among the suspended ventilation systems, the following varieties can be distinguished:
- wall;
- corner;
- island.
The first ones are the most common. They are made in a variety of design options, so it is easy to choose a product that is suitable in appearance to previously purchased furniture.
Island products can be placed anywhere in the room, as they are mounted to the ceiling. Such designs are often used in design options for kitchen furniture.
Built-in and suspended ventilation systems
A typical kitchen has a fairly standard set of furniture needed to store food and utensils. The exhaust ventilation system must fit into the interior created by these items, without taking up a lot of space, which is usually not enough in many older houses. Kitchen ventilation can be performed:
- built into a wall cabinet or table;
- suspension.
The first ones easily fit into any interior and are especially good when the kitchen is made to order. There are many design projects that allow you to hide the technical elements of the structure inside the furniture, so the presence of powerful exhaust ventilation in it can be guessed only after it is turned on.
Hanging products are the most popular and common.They can be purchased separately and installed in addition to the existing kitchen furniture, but they can also be part of a set made to order for a specific room interior. Such structures are mounted above the stove and have a variety of designs and technical features.
How to properly organize the hood in the kitchen with a gas stove
For today day almost all cuisines in private houses and apartments are equipped with a hood, and this is a problem. The problem is not in the hood itself, but in the fact that the ventilation ducts are far from always designed for its use. Standard air ducts in our dwellings have a section of 130x130mm, and their maximum capacity is 180m3/h. But modern "umbrellas" have a capacity that exceeds the throughput by several times, and this has an extremely negative effect on the operation of the general house ventilation system, as well as the ventilation of one's own apartment.
In order to properly organize the ventilation of a kitchen with a gas stove, you need to make it mixed, i.e. correctly combine the work of the exhaust "umbrella" and natural ventilation. This can be done in two ways.
- Connect the kitchen hood air duct to the air outlet duct, above the grille of the natural ventilation system. Moreover, the air duct must be directed to the shaft with a turn upwards.
- The second method involves connecting the kitchen hood duct, above the natural ventilation opening, without filling it into the shaft. But at the same time, the ventilation grill must be equipped with a check valve so that it overlaps the grill when the exhaust “umbrella” is operating.
