The microclimate in the house is of great importance, and its condition depends on how correctly the ventilation system is equipped. This affects not only the well-being of the inhabitants. Without effective air exchange, humidity increases, as a result, condensation appears, the tree begins to rot, the metal begins to rust.
In order to avoid such troubles, you need to know how to make ventilation in a two-story house competently so that life in it is comfortable.
From the article we have proposed, you will learn everything about the options for arranging systems that provide the air exchange necessary for life. We will introduce you to the peculiarities of the organization of ventilation of two-story buildings. Let's talk about how calculations are made for the correct selection of equipment.
The content of the article:
-
Existing types of air exchange
- Natural ventilation of the house
- Forced ventilation of a two-story house
- Mixed type specificity
- Features of the organization of ventilation on the second floor
- Calculation of the main parameters of the ventilation system
- Conclusions and useful video on the topic
Existing types of air exchange
Based on the method of inducing air movement, there are three types of air exchange:
- natural;
- forced;
- mixed.
Each of these types has advantages and disadvantages. To figure out which option has more advantages, you need to familiarize yourself with all the details.
Natural ventilation of the house
For natural air exchange in a two-story house, you do not need to install equipment that stimulates air movement. Everything here is based on the rules of physics - gravity, the principles of changing the pressure of gases.
Gravitational circulation occurs due to the leakage between structural components in windows and doors. Due to a change in the physical state, air masses that have penetrated from the street inside move independently into the vents, the system ventilation ducts. At the same time, the heat transfer of the premises increases.
A typical solution for private two-storey houses is a ventilation duct located vertically and brought out to the roof. This is ideal for a newly built house, since the box must be provided for in the project and mounted during the construction process.
Correct installation of the ventilation duct and the supply of hoses to it from the premises provides sufficient traction regardless of the vector and strength of the wind
Uninterrupted service of the natural ventilation system in a private two-story house is impossible without good traction.
It depends on a number of indicators:
- temperature differences inside the room and outside its outer walls;
- the height of the shaft and its section;
- wind that worsens or improves traction;
- the quality of the thermal insulation of the channel;
- the presence of turns, bends in the duct.
When the temperatures inside and outside are balanced, cravings deteriorate. A significant increase in the outside temperature will result in reverse draft. The way out is a ventilation shaft of great height.
Air enters into rooms such as the dining room, bedroom, living room, and is removed through utility rooms. The first ones are called dry, and the second ones are called wet. Thus, dry air enters the house, and moist air is removed.
Supply air masses enter the house through supply valves installed in the walls. They can be covered when necessary. When installing the system, the incoming channels are made from below, and the outgoing ones from the top so that they go out to the roof.
This construction is based on the fact that cold air, which tends to displace warm air, will always be at the bottom, and warm at the top. Air circulates between rooms through a gap at the bottom of the door of at least 1.5 cm.
Sometimes the air intakes are cut into the upper area of the wooden window frames. The same device is available in plastic windows with climate control.
The use of a natural air exchange pattern is justified if the house is located in an area where the air is really clean. The operation of such a system does not require additional electricity costs. If the scheme meets all the requirements, the rate of air exchange can be adjusted.
Forced ventilation of a two-story house
The operational parameters of a forced-type hood in a two-story private house are much higher than that of a natural one, since additional equipment is involved in the air exchange. There are three types of forced air exchange systems according to the principle of operation: supply, exhaust, supply and exhaust.
According to its functional purpose, mechanical ventilation is divided into two categories - local and controlled. The first works only in one specific place, and the second, in the future, can ventilate the house completely. An example of local exhaust ventilation is a cooker hood.
The exhaust air flows are removed through a channel with an exit to the roof. As with natural ventilation, air inlets are located in dry rooms, and exhaust air vents are located in rooms with high humidity.
The functioning of the controlled system is based on a central fan. As a rule, it is mounted in the attic and connected to the air intake ducts with pipes - flexible or rigid
The advantages of forced ventilation are as follows:
- intensive air circulation due to high discharge speed;
- exclusion of the influence of external factors;
- controllability process;
- the ability to pre-prepare the incoming air masses.
For the device of the supply circuit, the same supply valves are used as for natural ventilation. The only difference is in the presence of a fan blowing air into the room. Install it in an air duct laid in the wall. From the side of the room, the channel is closed with a lid, and from the street - with a lattice so that dust, various animals, and precipitation do not get inside.
Install supply valve not difficult. A hole is made in the wall using a drill or perforator. Then they clean it, lay the air duct, mount the valve and the protective grill.
More advanced functionality has breather. A fan, protective grilles, an air duct are also present here. But besides this, there are sensors that control humidity, temperature, if necessary, they automatically start the equipment.
Majority breathers equipped with a built-in convector that heats the air entering the room. This allows you to maintain a constant temperature, which is not only comfortable, but also reduces heating costs.
Equipment for organizing a ventilation system in a private house with two floors is installed in places where air removal is extremely necessary - in the kitchen, sanitary unit.
The hood device in the bathroom is due to high humidity, ignoring which will lead to the formation of mold, which carries a direct threat to health
A fan is also used as exhaust equipment for the bathroom. Place it at the entrance to ventilation duct, then masked with a protective grill. It does a good job of normalizing indoor humidity levels.
Along with humid air, it is necessary to remove unpleasant odors and fat from the kitchen. Cooker hood mounted above the hob and connected to the ventilation duct. A fan located inside the equipment draws out and removes the exhaust air masses from the room.
In a large two-story house, a forced draft system may not be efficient enough. This is explained by the fact that dirty air is forced out, and fresh air enters naturally in a small volume. Under these conditions, a more acceptable option is supply and exhaust ventilation.
For this combined system, air is drawn in and out by fans. The building envelope must be highly airtight. Often the role of supply equipment is played by breathers, and in wet rooms, exhaust mechanisms are mounted.
Thus, the intensity of air exchange increases, and the volume of air masses, both introduced and removed, will be under control. In more powerful systems, in addition to supply and exhaust equipment, there is heating or cooling. Sometimes humidifying and air filtering devices are additionally mounted. Most complex systems are equipped with a recuperator.
The recuperator allows you to seriously save on heating in the cold season, because the supply air is heated. Its plate version is a dimensional unit, therefore it is installed in a separate room.
The supply air jets, before entering the house, pass through the heat exchanger, meeting with the warm air rushing outside. Structurally, the unit is designed so that air avalanches do not mix, but a warm jet heats up a cold one. The latter comes to the house already warm.
In all respects, forced centralized ventilation with recuperation is the most perfect way to equip a ventilation system, since it allows you to solve many problems at once:
- to establish optimal air exchange throughout the house without focusing on weather conditions;
- prepare the supply air;
- automate and regulate air exchange in a significant range, based on different indicators of the microclimate in individual rooms;
- save heat energy.
The implementation of the forced scheme is associated with considerable financial costs. The equipment that is part of it requires periodic maintenance. In addition, such a ventilation model requires the constant presence of a power supply for its operation.
It is advisable to provide backup power when installing a forced ventilation system in a two-story house. It will be useful not only for maintaining the microclimate in the premises, but also will allow you to enjoy all the other benefits of civilization.
Mixed type specificity
The mixed type of ventilation involves the use of both a gravitational scheme and a mechanical one, i.e. forced. Typically, in such systems, ventilation devices that provide air exchange in a two-story house, fans are installed both on the exhaust components and on the supply air.
Depending on the state of the atmosphere and microclimate inside the house, in mixed systems, either an exhaust or an inflow is turned on. At activation of the hood air masses from the street will spontaneously flow into the vacated rarefied space. If the inflow is started, the forced air will itself displace the excess.
Features of the organization of ventilation on the second floor
Natural ventilation on the second floor can be arranged in two ways. The first of them provides for the presence of an entrance door that blocks the air flow from below. Thus, the airspace is divided into independent blocks.
The door from the stairs to the second floor must have an effective seal. In addition, it is advisable to install a door closer here. It will automatically return the door to its original position
It is also possible to divide the airspace of the floors with the help of a door installed in front of the stairs leading up.
The scheme of natural ventilation of the second floor is similar to that of the first:
- Clean air enters the rooms through a wall or window supply valve.
- Through leaks or overflow air from the rooms flows into the bathroom, other auxiliary rooms.
- Dirty air flows out through the ventilation shaft.
Supply valves are installed in living rooms, exhaust valves are installed in a dressing room, hallway, bathroom. At the doors of all rooms they leave overflow slots or gratings are installed.
In order for the ventilation to function normally, it is necessary not only to ensure the tightness of the front door to the floor. It is necessary to eliminate other ways of possible cross-flow of air jets between floors - places where communications pass, leaks in the ceilings.
The second method is used when the layout is made in such a way that there is no door from the stairs to the second floor. Here, the air space of each room is individually insulated.
For this purpose, inlet valves are cut in all the rooms of the second floor, and the doors are made sealed and constantly kept closed. To remove contaminated air masses in rooms, natural ventilation channels are provided.
The disadvantage of the second method is the need to increase the number of ventilation ducts. Ideally, each room should have an individual duct ending on the roof.
When combining the ventilation ducts of a two-story house, you cannot connect bathrooms and kitchens with living rooms. It is unacceptable to combine and place near each other extracts of sewer risers and ventilation systems of premises
Combining ventilation ducts degrades system performance. There are times when it is still necessary to do this, but even if this option is chosen, the design will turn out to be rather complicated.
There are circumstances in which it is not always possible to create the necessary air exchange with the help of natural ventilation on the upper floor:
- It is practically impossible to completely exclude air exchange between floors.
- The ventilation ducts of the second floor have a lower height, therefore, the traction force in them is lower in comparison with the ducts of the lower level.
For these reasons, it is better to use forced exhaust ventilation to ensure a comfortable environment.
Calculation of the main parameters of the ventilation system
For the device of effective ventilation in a two-story house, a preliminary calculation is required, based on the air exchange standards specified in SP 55.13330.2011. The main purpose of the calculation is to determine the size of the ducts in accordance with the volume of air to be removed.
In the construction of the ventilation system of a two-story house, equipment of greater capacity is needed than for a construction on one level. Usually, a ventilation unit with a capacity of at least 400 m3 / hour is included in the project.
The calculation is done for each floor, observing the following sequence:
- Find, according to table 1 of the Building Regulations, the total minimum volume of air (Qп) coming from the street in the amount required for ventilation of rooms equipped with supply valves.
- The total minimum volume of air masses to be removed (Qw) from all rooms equipped with an exhaust duct is selected from the relevant section of the standards.
- The obtained minimum parameters (Qp and Qw) are compared. The larger value will be the smallest design air capacity (Qp) of all exhaust shafts on the floor.
- Based on the value of the height of the house, they choose the size of the shaft on the floor vertically.
According to the height of the ventilation shaft and the minimum capacity of the channels located on the second floor, the number of shafts is selected according to a special table.
The table shows the performance of a single exhaust ventilation duct made of concrete blocks in relation to its height and room temperature. Channel section 204 cm²
The selected standard channels must have a total productivity in mᶾ / hour not less than the calculated Qр. The shafts are distributed between the rooms so that the standard air exchange in each of them is ensured.
If it turns out that air speed and the performance of the duct is insufficient, then the length of the shaft or the section is increased. To ensure equal thrust in each duct, all ducts on the floor must have the same length.
It should be noted that the above calculation scheme is a simplified version. A professional calculation is much more complicated and can only be performed by a specialist.
Conclusions and useful video on the topic
The author of this video told about the creation of ventilation in a private house and the solution of problems arising during its installation:
The installation process of supply ventilation is shown in the video clip:
Reasonably executed ventilation system in the house is the key to the health of the people living in it. But this is not its only task - it must preserve the structural elements of the building from gradual destruction under the influence of high humidity.
Information on the types of ventilation systems, operating features will help you choose the best option for optimal air exchange in the house.
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