Residents of high-rise buildings who decide to move to the private sector expect that closeness to nature and the desire for privacy will immediately appear in all their glory. There will be no dull urban landscapes in the window, there will be no noise of a big city coming from the windows, there will be no smells that inevitably appear from transport and the fruits of the life activity of many people living compactly. You will be able to breathe clean natural air and enjoy life. But imagine the surprise of new households when the windows in their country home fog up, the air turns out to be very humid, which is very difficult to breathe, and at the same time it can carry with it the “aromas” of the basement. And in this case, beautiful landscapes will not be so pleasing to the eye. And this phenomenon is far from uncommon. The diagnosis here is clear - problems with ventilation.
What would any normal person do if he finds himself in a similar situation? Naturally, he will try to contact specialized organizations that professionally deal with ventilation. And the likelihood that the problem will be solved is very high, since there are now enough specialists, and there are no problems with the equipment either. But we encourage you to first study this issue a little on your own, and then decide whether to apply or not. Is it possible that the problem is trivial and can be resolved on its own? In our article: “Ventilation in a private house: diagram and installation,” we will try to tell you everything we know about these issues. And we are going to do it in such a way that it is understandable to everyone, and not just to those who are not familiar with engineering.
We believe that FORUMHOUSE users will agree with the statement that a competent approach to the ventilation system is as follows - first of all, it is necessary to calculate the air exchange, then, based on this data, select the required cross-section of air ducts. And only after this can you draw up a ventilation scheme for the cottage and determine the installation location of the ventilation equipment.
Types and features
According to the user our portal (nickname on the forumpetrovk, Moscow) ventilation in the house can be divided into three types:
- Natural;
- Inflow, or as it is also called, mechanical;
- Supply and exhaust unit with heat recovery.
petrovk:
– When designing a ventilation system, you should be guided by the following principle – The air in the house should be completely renewed within 1 hour. For my frame house of 200 m2, I settled on a flow-exhaust installation with heat recovery. The installation is selected based on the number of cubic meters of air in the house, I have 600, I took the installation for 700 cubic meters.
It should be remembered that a comfortable environment in the house is created not only due to the supply of fresh air, but also due to the speed of air flow. Supply and exhaust ventilation, due to the presence of a fan in it, creates a greater air flow than natural ventilation.
When mechanical ventilation is operating, the air movement speed in the ventilation system is on average 3-5 m3/hour, and with natural ventilation it is about 1m3/hour. Let's try to figure out whether natural ventilation creates a more comfortable environment in the house. This question is not as simple as it seems. After all, in order to pass the same volume of air through the mechanical and natural ventilation systems, a different cross-section of the ventilation duct is required. This means that the installation of natural ventilation will entail an increase in the cross-section of the channel, which is not always possible from a technical or aesthetic point of view.
With any type of ventilation - regardless of whether it is natural or mechanical - it is necessary to ensure unhindered air movement throughout the house.
One option is to install doors with a cross-flow grille in the rooms or leave a small gap between the door and the floor. To properly organize the flow of air, it is necessary that the air be taken in in the cleanest room, the living room or bedroom, and taken out in the kitchen or bathroom.
In the kitchen, above the stove, the hood should run through a separate channel. If the hood is forced, then the kitchen and bathroom can be combined with one ventilation duct. The diameter from inlet to outlet should not decrease. Due to the specific nature of the kitchen hood, the air duct from it must be round, galvanized and vertical, without elbows. Do not use corrugated, aluminum or plastic ductwork.
Consultant of our forumElena Gorbunova(nickname on the forum Matilda ):
– Natural ventilation works when there is a pressure difference between the inlet and outlet. The entrance is an exhaust valve; it is placed in the ceiling of the room or in the wall under the ceiling. The exit is the top of the pipe. The drop starts from 10 meters. The pressure difference also depends on the temperature difference. It is better in winter and worse in summer.
Natural inflow is made over heating appliances, which are usually located under the windows. Or two meters above the floor.
The question often arises,
Is it possible to combine the ventilation ducts of the kitchen, bathroom and boiler room into a single system, then install a duct fan, and take everything out through the roof with one pipe.
User of our forum Vladimir(nickname on the forum Careless Angel ) believes that:
– Under no circumstances should you combine the exhaust hood with the sewer, then the whole house will smell like a toilet, regardless of whether the air duct is installed before or after the fan.
The material from which the ventilation ducts for a private home are made is also of great importance. One of the best options is the use of spiral-wound galvanized air ducts. But during self-installation, developers massively use ventilation ducts made from a sewer pipe with a diameter of 110 mm.
Matilda
:
– Sewage pipes cannot be used. In general, plastic cannot be used for air ducts, unless these are special antistatic pipes. In this case, dust will stick to the walls. In addition, sewer pipes have a small diameter. And the draft directly depends on the diameter of the air duct and the height difference. The difference in the cottages is quite small - this is not a high-rise building. This means that with a small diameter, there will be practically no traction, especially in summer. And if you install a fan, the sewer pipes will make a very unpleasant sound when the air moves.
Air ducts for ventilation for private homes - requirements and features
In order for the ventilation system to work with maximum efficiency, it is necessary that the inner surface of the air duct provides minimal resistance to air movement. Let's see how to choose the right one V air ducts for ventilation of your home.
Matilda :
- The main task
ducting is to allow air to move freely from the point of air intake to the point of its exit. And be safe from an environmental and fire safety point of view. Any loss of pressure greatly affects or eliminates air exchange during natural ventilation. Pressure losses arise from the uneven surface of the air duct, in horizontal sections, in elbows, tees, etc. With a rectangular duct shape, losses are higher than with a round one, and dust accumulates in them well.
Flexible - corrugated air duct has the greatest air resistance. And it is best used when it is necessary to make a turn or attach a kitchen hood to the ventilation duct.
Very often, developers, for various reasons, do not want to install the outlet through the roof, preferring to install the ventilation duct through the wall. It is not right.
Matilda
:
– Never, under any circumstances, vent through a wall. You'll ruin the façade.
Within a couple of years there will be a visible stain on the wall around the exit.
And thus, it is also pointless to remove natural ventilation, since there will be absolutely no difference in height, and, accordingly, pressure.
If, with a forced ventilation system, all air ducts are connected by elbows and adapters to one vertical duct, then it is recommended to install an E190P fan on the roof.
To control this fan, a thyristor speed controller is placed in a convenient place. And the air ducts themselves are taken with a diameter of 125 mm.
At FORUMHOUSE you will find an article about, a lot of useful information, a fascinating discussionchoice And after reading our video, youYou will be able to clearly see how an integrated approach to ventilation design allows you not only to provide your home with fresh air, but also to save money.
Good ventilation is a system that ensures efficient air exchange, regardless of the season. During the summer it provides a little coolness, but in winter it should not let too much heat out of the house. What a lack of ventilation means is best known to the residents of houses who replaced windows from old frames with cracks to sealed modern ones, and as a result they received: sweaty windows, stuffiness, and sometimes mold on the slopes and walls. When building our own home or renovating, we want to do everything right so as not to have such problems. The house should be warm and cozy, not too dry and damp, even in winter. How to achieve this?
Already at the design stage you should think about ventilation, then it will not be difficult to create a truly modern and efficient system. How to properly ventilate a house, is natural ventilation sufficient or is mechanical ventilation needed, how to ensure it - this article is devoted to these issues.
Why is ventilation in a private home so important?
Ventilation is the exchange of air in rooms. Exhaust air is exhausted outside, and fresh air enters the rooms. What if this doesn't happen? Various pollutants will accumulate in the room - mainly exhaled carbon dioxide, as well as the ubiquitous dust, dust mites, and mold spores. There are also harmful chemicals emitted by furniture and various equipment, and if there are smokers in the house, there are also toxic compounds carried by cigarette smoke.
The air exhaled by people and the steam coming from the kitchen and bathroom cause an increase in humidity. Water vapor is deposited on cold surfaces, such as windows and corners of the room. Damp surfaces provide a breeding ground for dust mites, which live in house dust and mold. These microorganisms can cause allergies. Mold spores attack food and can also destroy the wall on which its colony forms.
Spending a long time in rooms that are poorly ventilated is very harmful. This stimulates drowsiness, headache, dizziness, poor attention, weakness. We may feel nauseated and generally tired and even depressed. Sometimes the body can react to stuffiness with irritation of the eyes and respiratory tract, and even cardiac arrhythmia. In addition, the carcinogenic impact of mold should not be underestimated. Therefore, it is very important to get rid of ventilation problems, if any.
It is known that the ventilation system must operate in the house and continuously remove any air pollution. In addition, it is necessary to ensure the safe use of gas appliances - boiler, heater, stove, fireplace. In case of any malfunction of these devices, toxic gases should be removed from the house immediately.
It is also necessary to remove excess moisture from the house, released by our breath, accumulated as a result of cooking, drying clothes, as well as odors that appear in indoor living spaces.
How much fresh air does your home need?
To provide housing with a sufficient amount of fresh air, it is first necessary to determine the need for air exchange. How to do it?
General recommendations and examples of calculating fresh air requirements
- within an hour, as much air in the room must be replaced as the cubic capacity of the room;
- For each person living in a room, 30 m³ of air is needed per hour.
It is advisable to choose the larger of these two values.
Example.
A living area of 20 m² requires an exchange of 50 m³ of air per hour, but if it is a bedroom for two people, then 60 m³/h.
There is also an approach to calculation, which assumes that sufficient air exchange is 0.5-0.8 of the volume of the room per hour.
Example.
A living area of 20 m² requires an exchange of 25-40 m³/h.
However, it should be taken into account that in conditions of more intense pollution, more intensive air exchange will be required.
Types of ventilation - diagram
Depending on financial capabilities and preferences, we can use two types of ventilation:
These recommendations should not be taken too literally. They may not be sufficient in a home where cigarette smoking, many people live, or where guests are frequently received. The amount of pollutants released is also affected by:
- how often and how many people wash and dry clothes;
- how many times a day do they take a bath or shower;
- how often it is cooked;
- type of oven (gas or electric);
- and even the location of the house - if it is in the shade, it will collect more moisture, which also provokes pollution.
The amount of fresh air that rooms such as the kitchen, bathroom, and toilet should receive is slightly different. They require intensive ventilation during use. So:
- the bathroom requires at least 50 m³/hour of fresh air;
- toilet – 30 m³/hour;
- pantry – 15 m³/hour;
- kitchen with electric stove – 50 m³/hour;
- kitchen with gas stove – 70 m³/hour.
Separate requirements apply to the living room with a fireplace, boiler room, laundry room and drying room.
How to determine whether the ventilation in the house is sufficient using the home method?
A home way to check whether ventilation is sufficient is to measure the indoor humidity during the winter. If it is no more than 50-60%, this means that the ventilation is working properly.
The amount of fresh air that must be delivered to the room, as can be seen from the calculations given above, is very large. And in winter it will have to be warmed up, since the fresh air is quite cold. This will entail very high costs, which will be higher the colder it is outside.
Therefore, ventilation systems should be assessed not only in terms of investment costs, but also taking into account operating costs. How to properly make supply ventilation?
Natural gravity ventilation
The simplest is a natural ventilation system. Air enters the room through ventilation openings and is removed through exhaust ducts. This system is inexpensive to produce. However, its disadvantage is the high cost associated with heating the incoming cold air - in a natural ventilation system we cannot completely control the amount of air that enters the room. The colder it is, the more cold air masses come in, and the more we spend on heating.
Mechanical ventilation
Another option is mechanical ventilation, in which a fan increases the air exchange in the home. Depending on the location of the fans and the entire system, ventilation can be exhaust or supply and exhaust. It can control the amount of fresh air that enters the interior of the house, but unfortunately we will have to pay additional heating costs again.
However, it is possible to reduce air heating costs. Cold air entering a room can be preheated using heat from exhaust air from the home or heat stored in the ground. For this, recovery devices are used (which we will discuss in this article below). They allow the supply air to be preheated, thus reducing overall heating costs.
How does natural ventilation work in a house?
How to properly make natural ventilation in the house?
What does the installation of natural ventilation in a house consist of and how to make a ventilation system correctly?
The ventilation system consists of diffusers through which fresh air enters the house and ventilation ducts through which air is removed from it.
Diffusers can be factory installed in windows, but you can purchase completely sealed windows and install the diffusers in the wall. If you place them at a height of about 2 meters, then people will not feel cold air currents, since the outside air has time to mix with the warm air in the room. You can also install ventilation holes above the radiators - this way the cold air will immediately heat up.
Diffusers can be controlled manually or automatically. Using cheaper manual models, adjust the degree of opening of each of them. More convenient are automatic models that regulate the amount of incoming air to a specific level - pressure or humidity, less often: temperature, which is measured indoors and outdoors.
Ventilation ducts. The used air is blown out through the vents in the ventilation ducts. If they are equipped with a damper, you can regulate the amount of exhaust air and reduce it when the weather is too cold.
How to cheaply increase the efficiency of ventilation in your home?
The easiest and cheapest way is to install exhaust fans in the ventilation ducts. They can be controlled manually or automatically (for example, they can respond to the turning on of a light or movement in the room). The air flow in this case is carried out in the same way as in gravity ventilation systems - through diffusers. Fans are usually placed in the kitchen, bathroom and toilet, or where there are odors and moisture that need to be removed as quickly as possible.
Using a fan provides effective ventilation of the house on warm summer days, but it also has disadvantages:
- additional costs associated with the electricity consumption of these devices;
- Another disadvantage is the noise they make, which can be avoided by installing fans at the end of the exhaust duct on the roof.
Is it possible to control the air supply and exhaust?
Regulation of not only the amount of exhaust air, but also the supply can be ensured in the supply and exhaust ventilation system. How to properly install exhaust and supply ventilation? This requires two fans - supply and exhaust, which can be placed away from the rooms, for example, in the attic - this is a good option.
The fans are connected to all rooms via two pipelines: supply and exhaust. One provides fresh air, the second removes polluted air. Although this requires more money, in this way you can completely control the amount of air entering individual rooms, and we can also install additional equipment in such a system:
- filters that purify incoming air;
- air heater for preheating;
- an air humidifier, which will improve its quality in winter, when the rooms are usually too dry.
How to save energy used for ventilation in the house?
Installing a supply and exhaust installation usually entails another solution - installing a heat recovery (that is, recovery) system. Although the air handling unit is expensive, and with a heat recovery air handling unit it will be even more expensive, this design will help reduce operating costs, which will pay off in the future through heat savings.
When ventilating a house in winter, we lose a lot of heat, which is removed outside along with polluted air. The incoming fresh air needs to be heated - and this can increase by up to half the cost we pay for heating the house during the same time. If, for example, the cost of heating is 3,000 rubles, then taking into account ventilation losses, it can rise to 4,500 rubles!
That's why there is increasing interest in devices that can retain some of the heat that would normally be lost through heat recovery, as well as through a ventilation system in which fresh air is preheated in the ground.
How does heat recovery ventilation work?
How to properly ventilate a room so that it is energy efficient? A modern and relatively simple method is recovery. The main element of such a system is a heat exchanger - recuperator. A stream of cold air passes through it and a stream of exhaust warm air is released. The special design of the heat exchanger allows the exhaust air to transfer some of the heat to the incoming air. How efficiently a device transfers heat depends on the indoor and outdoor temperatures, humidity and the design of the heat exchanger.
This device is useful not only in winter. On hot summer days you can cool the supply air in this way.
It is not beneficial to use a recuperator only during transition periods, when the temperature difference between inside and outside is small and heat recovery becomes uneconomical. In order for air to pass through the recuperator, two fans are needed - for air supply and air exhaust, and their operation also costs money, since they also consume electricity.
The heat exchanger with fans is part of a device called a heat recovery ventilation unit. In addition to the heat exchanger, the thermally and acoustically insulated housing panel contains air filters and sometimes a heater.
The external elements of a heat recovery system are an air intake through which air enters the interior, and an outlet chute located at a distance from the air intake through which the exhaust air is discharged outside.
Fresh air enters the housing through air intakes, where it is cooled in the summer and warmed up in the winter, and enters the room through ventilation ducts. The exhaust air is discharged from the ducts back into the body of the device, where it gives off heat and is then removed from the building.
The recuperator can be installed in the attic or basement. This requires four connecting pipes - two inlet and two outlet. The exhaust air inlet is connected to the pipe system in the kitchen, bathroom and toilet, and the fresh, heated air outlet is connected to ventilation ducts with adjustable end diffusers located in the living room, hallway and bedroom. The remaining two tubes go outside the building.
What types of recuperators can be used in the ventilation system?
The most popular are plate-type recuperators. Their operation is very simple - streams of hot and cold air flow parallel to each other between the heat exchange plates, which ensures heat exchange without mixing. Two fans move the air. The efficiency of heat recovery in such a recuperator is 60-70%.
Counterflow heat exchangers are designed very similarly, only the air passes through them a little differently. Such devices are larger in size, but have higher efficiency - up to 90%.
Tubular heat exchangers are sometimes used, however, due to their large size, their use is limited, despite their relatively high efficiency - above 90%.
Rotary heat exchangers can also be found on sale. They are very efficient - efficiency is 80-90%. But they can allow a small amount of exhaust air to enter the fresh air, which can lead to the spread of odors in the house. Their advantage is partial removal of moisture. Proponents of rotary heat exchangers say odor transfer is negligible. Such models are very popular in the Nordic countries - Scandinavia.
In a house where allergy sufferers live, you can use a filter to supply air, thereby removing allergenic particles.
When purchasing a recuperator, you should choose a model with a smooth five-stage variable fan speed. The more adjustment possibilities, the better the recuperator regulates the speed in accordance with the air exchange needs.
How can you use the natural heat of the earth in a ventilation system?
If fresh air enters the house through a ground heat exchanger, this will allow the ventilation system to use natural heat or cold that accumulates in the ground: at a certain depth, the ground temperature is almost constant and does not depend on the outside air temperature. Such a heat exchanger can be used all year round - in winter it warms the outside air and cools it in summer. The efficiency of heat transfer depends on the surface area of the heat exchanger, the depth at which it is located and the intensity of the air flow.
A ground heat exchanger is built as a pipe system or a layer of gravel is used. Air is drawn in through the inlet. The cold obtained from the earth can completely satisfy the needs of a private single-family home during hot weather.
A precondition for proper operation of the heat exchanger is that it is properly sized. It can't be too small because the ground will then stop giving off enough heat or taking it in during periods when the system is being used for cooling. Such a device does not require electricity and is therefore very economical.
The ground heat exchanger for recovery only works when it is hot or very cold. During the transition period, it is turned off and air is exchanged from an external air intake located on the wall of the building.
How to properly ventilate your home - video
Thanks to publications in the media, now everyone knows that ventilation is the most important engineering system of any room. Poor ventilation in a house can lead to illnesses in its inhabitants and to the failure of finishing materials and building structures.
When designing the ventilation of a private house, most developers take into account the layout of the building and the materials used in construction. But to create an effective ventilation system, it is necessary to take into account climatic conditions, as well as the operating mode of the building. The features of ventilation of a private house in winter will be discussed in this article.
Possible ventilation schemes for a private house
The home ventilation system is responsible for removing excess moisture and exhaust air from the premises. Based on this, the following air exchange schemes can be used in private homes:
- Natural supply and exhaust ventilation of rooms where the inflow is organized through the natural leaks of windows and doors.
- Mechanical supply and exhaust system, providing air exchange through fans.
- Combined systems with natural exhaust and forced fresh air.
Each of these schemes requires competent design and calculations. But if in the warm season problems with ventilation can be solved by opening a window or vent, then in winter this cannot be done without losing precious heat.
Problems associated with natural ventilation in winter
When constructing private houses in our country, natural ventilation is most often used. It has a lot of advantages, among which the most significant for the developer are ease of implementation and low cost of execution. But its use also has one drawback - the influence of the temperature difference between the house and the street on the circulation of air flows: the greater the difference, the better the air exchange.
The problem with natural ventilation at home during the cold season lies precisely in increased air exchange, during which up to 40% of the heat is released into the atmosphere along with exhaust air and, as a result, heating costs increase.
But if we are talking about the ventilation system, we cannot help but touch upon the problem of underground ventilation in a private house in winter.
The space under the floor must be ventilated to prevent condensation from occurring on joists and insulating floor structures.
When organizing uncontrolled ventilation of the subfloor in winter, heat loss through the floor can reach 20%. If we add to this the possible losses that increased air exchange creates, we get a significant figure. Many owners of private houses with basements solve the problem of heat loss during natural ventilation of the subfloor in wooden houses in winter by closing the vents. This, as a rule, helps to reduce losses, but there is a risk of condensation, rot and mold damage to wooden structures in the “pie” of the floor.
We cannot ignore the issue of organizing ventilation of the attic space. If there is insufficient air circulation in the attic in the summer, a hot roof will increase the air temperature in living spaces, which may result in additional costs for creating an air conditioning system. In winter, on the contrary, good air exchange in the attic will contribute to significant heat loss through the ceilings. At the same time, condensation may form in the roofing pie and the attic room, which will negatively affect the condition of the rafters and the thermal insulation layer.
Conclusion 1: Natural ventilation cannot fully guarantee high-quality air exchange and heat retention in a private home.
Advantages and disadvantages of forced ventilation in winter
Mechanical ventilation in a private home has a lot of advantages, among which the most significant is control of air exchange volumes and air circulation speed. The use of mechanical ventilation will allow you to adjust air exchange and, therefore, reduce heat loss.
But even here, not everything is smooth, since the year-round use of mechanical ventilation “results” in significant financial costs for paying bills for the use of electricity.
Conclusion 2: The constant use of a forced ventilation system in private homes may not be economically viable.
Methods for rational creation of ventilation
Taking into account climatic conditions and the economic component, the most rational way to organize air exchange in a private house may be combined ventilation. In summer, the house will be ventilated using natural inflow and exhaust. In winter, air exchange in the room will be carried out by a forced system, which includes supply and exhaust fans, filter elements, a recuperator and automation. The use of such a system in a private home will save up to 25% of heat and compensate for the financial costs of paying for electricity consumed by the mechanisms. 
There is another way to provide controlled ventilation in a private house, in which a ground heat exchanger is used instead of a recuperator. To do this, it is necessary to organize the flow of outside air through a heat exchanger placed in the ground below its freezing level. Cold air masses will be heated by the natural heat of the earth, which will reduce electricity consumption for heating the supply air in the cold season.
Question to the expert
Many people ask whether it is possible to turn on the air conditioner for ventilation in the winter to effectively mix the colder supply air with heated air in the living room? Let's begin with The use of household air conditioners in the cold season is prohibited. If available, you can expand the range of operation of climate control equipment, but only for cooling (not heating)! In ventilation mode, only the fan of the indoor unit works, which drives the air masses in the room through the filter. That is why it is possible to turn on the split system in the “ventilation” mode in winter.
Air exchange is ensured by draft in the exhaust air duct system. They start in rooms (usually in the kitchen and bathroom, in the dirtiest rooms in the house). Then the air ducts go up to the attic and from there to the roof.
Air draft is created in these ventilation ducts. Due to this, the exhaust air from the house goes outside. And to replace it, fresh air enters the house - through windows, doors, leaks in the walls and double-glazed windows.
Air moves through exhaust ducts due to two simple laws of physics:
- Warm air tends to rise
- Air tends to where the pressure is lower
Factors that influence the draft force in air ducts:
- Temperature difference between exhaust and street air
In winter, the draft is stronger because warm room air tends to rise through the exhaust ducts. In summer there is no temperature difference, there is zero draft - and air exchange practically stops. - Vertical distance between room and roof
At the top, the pressure is lower than at the surface of the earth. Therefore, the higher the exhaust duct ends, the greater the pressure drop. Which means the traction is stronger. - Wind speed and direction
Wind occurs when atmospheric pressure is distributed unevenly. If there is a zone of high pressure near the windows, and at the exit from the exhaust pipe there is a zone of low pressure, then the air will easily enter the house and easily go out.
We cannot control the wind, pressure, or temperature outside the window. This is the main disadvantage of natural ventilation - dependence on weather conditions.
But there are a few tricks that will help you properly create natural ventilation in a private home with your own hands. Some of them can be used only at the design stage, others - even in a completed house with a complete renovation.
