Ventilation in a room, especially in a residential or industrial one, must function at 100%. Of course, many may say that you can simply open a window or door to ventilate. But this option can only work in summer or spring. But what to do in winter when it's cold outside?
The need for ventilation
First, it should be immediately noted that without fresh air human lungs begin to function worse. It is also possible the appearance of a variety of diseases, which with a high percentage of probability will develop into chronic ones. Secondly, if the building is a residential building in which there are children, then the need for ventilation increases even more, since some ailments that can infect a child are likely to remain with him for life. In order to avoid such problems, it is best to deal with the arrangement of ventilation. It is worth considering several options. For example, you can do the calculation of the supply ventilation system and its installation. It is also worth adding that diseases are not all problems.
In a room or building where there is no constant exchange of air, all furniture and walls will be coated with any substance that is sprayed into the air. Suppose, if this is a kitchen, then everything that is fried, boiled, etc., will give its sediment. In addition, dust is a terrible enemy. Even cleaning products that are designed to clean will still leave their residue, which will negatively affect the residents.
Type of ventilation system
Of course, before proceeding with the design, calculation of the ventilation system or its installation, it is necessary to determine the type of network that is best suited. At present, there are three main different types, the main difference between which is in their functioning.
The second group is the exhaust. In other words, this is an ordinary hood, which is most often installed in the kitchen areas of the building. The main task of ventilation is to extract air from the room to the outside.
Recirculation. Such a system is perhaps the most effective, since it simultaneously pumps air out of the room, and at the same time supplies fresh air from the street.
The only question that arises for everyone further is how the ventilation system works, why does the air move in one direction or another? For this, two types of air mass awakening source are used. They can be natural or mechanical, that is, artificial. To provide them normal work, it is necessary to carry out the correct calculation of the ventilation system.
General network calculation
As mentioned above, just choosing and installing a specific type will not be enough. It is necessary to clearly determine how much air needs to be removed from the room and how much needs to be pumped back. Experts call this air exchange, which must be calculated. Depending on the data obtained when calculating the ventilation system, it is necessary to start when choosing the type of device.
To date it is known a large number of a variety of methods calculation. They are aimed at defining various parameters. For some systems, calculations are made to find out how much to remove warm air or evaporation. Some are carried out in order to find out how much air is needed to dilute the pollution, if this industrial building. However, the minus of all these methods is the requirement of professional knowledge and skills.
What to do if it is necessary to calculate the ventilation system, but there is no such experience? The very first thing to do is to familiarize yourself with the various normative documents available in each state or even region (GOST, SNiP, etc.) These papers contain all the indications that any type of system must comply with.
Multiple calculation
One example of ventilation can be a multiplicity calculation. This method is rather complicated. However, it is quite feasible and will give good results.
The first thing to understand is what multiplicity is. A similar term describes how many times the air in a room is replaced by fresh air in 1 hour. This parameter depends on two components - this is the specificity of the structure and its area. For a visual demonstration, the calculation according to the formula for a building with a single air exchange will be shown. This indicates that a certain amount of air was removed from the room and at the same time fresh air was introduced in such an amount that corresponded to the volume of the same building.
The formula for calculation is as follows: L = n * V.
The measurement is carried out in cubic meters / hour. V is the volume of the room, and n is the multiplicity value, which is taken from the table.
If a system with several rooms is being calculated, then the volume of the entire building without walls must be taken into account in the formula. In other words, you must first calculate the volume of each room, then add up all the available results, and substitute the final value into the formula.
Ventilation with a mechanical type of device
The calculation of the mechanical ventilation system, and its installation must take place according to a specific plan.
The first stage is the determination of the numerical value of air exchange. It is necessary to determine the amount of substance that must enter the building in order to meet the requirements.
The second stage is the determination of the minimum dimensions of the air duct. It is very important to choose the correct section of the device, since such things as the purity and freshness of the incoming air depend on it.
The third stage is the choice of the type of system for installation. This is an important point.
The fourth stage is the design of the ventilation system. It is important to clearly draw up a plan-scheme according to which the installation will be carried out.
Need for mechanical ventilation occurs only if the natural inflow cannot cope. Any of the networks is calculated on parameters such as its own air volume and the speed of this flow. For mechanical systems, this figure can reach 5 m 3 / h.
For example, if it is necessary to provide natural ventilation an area of 300 m 3 / h, you will need it with a caliber of 350 mm. If mounted mechanical system, then the volume can be reduced by 1.5-2 times.
Exhaust ventilation
The calculation, like any other, must begin with the fact that performance is determined. The units of this parameter for the network are m 3 / h.
To make an effective calculation, you need to know three things: the height and area of the rooms, the main purpose of each room, the average number of people who will be in each room at the same time.
In order to begin to calculate the ventilation and air conditioning system of this type, it is necessary to determine the multiplicity. The numerical value of this parameter is set by SNiP. Here it is important to know that the parameter for residential, commercial or industrial premises will be different.
If the calculations are carried out for a residential building, then the multiplicity is 1. If we are talking about installing ventilation in an administrative building, then the indicator is 2-3. It depends on some other conditions. To successfully carry out the calculation, you need to know the value of the exchange by the multiplicity, as well as by the number of people. Need to take highest value flow rate to determine the required system power.
To find out the air exchange rate, it is necessary to multiply the area of the room by its height, and then by the multiplicity value (1 for household, 2-3 for others).
In order to calculate the ventilation and air conditioning system per person, you need to know the amount of air consumed by one person and multiply this value by the number of people. On average, with minimal activity, one person consumes about 20 m 3 / h, with average activity, the indicator increases to 40 m 3 / h, with intense physical exertion, the volume increases to 60 m 3 / h.
Acoustic calculation of the ventilation system
Acoustic calculation is a mandatory operation that is attached to the calculation of any room ventilation system. Such an operation is carried out in order to perform several specific tasks:
- determine the octave spectrum of airborne and structural ventilation noise at the calculated points;
- compare the existing noise with the permissible noise according to hygienic standards;
- determine how to reduce noise.
All calculations must be carried out at strictly established calculation points.
After all measures have been selected according to building and acoustic standards, which are designed to eliminate excessive noise in the room, a verification calculation of the entire system is carried out at the same points that were previously determined. However, the effective values obtained during this noise reduction measure must also be added here.
To carry out calculations, certain initial data are needed. They were the noise characteristics of the equipment, which were called sound power levels (SPL). For the calculation, geometric mean frequencies in Hz are used. If an approximate calculation is carried out, then correction noise levels in dBA can be used.
If we talk about design points, then they are located in human habitats, as well as in the places where the fan is installed.
Aerodynamic calculation of the ventilation system
Such a calculation process is performed only after the air exchange for the building has already been calculated, and a decision has been made on the routing of air ducts and channels. In order to successfully carry out these calculations, it is necessary to compose a ventilation system in which it is imperative to highlight such parts as the fittings of all air ducts.
Using information and plans, it is necessary to determine the length of individual branches of the ventilation network. Here it is important to understand that the calculation of such a system can be carried out in order to solve two different problems - direct or inverse. The purpose of the calculations depends on the type of the task:
- straight line - it is necessary to determine the dimensions of the sections for all sections of the system, while setting a certain level of air flow that will pass through them;
- the reverse is to determine the air flow by setting a certain cross section for all ventilation sections.
In order to perform calculations of this type, it is necessary to break the entire system into several separate sections. The main characteristic of each selected fragment is constant flow air.
Programs for calculation
Since doing calculations and building a ventilation scheme manually is a very laborious and lengthy process, we have developed simple programs who are able to do all the actions on their own. Let's consider a few. One such program for calculating the ventilation system is Vent-Clac. Why is she so good?
Such a program for calculating and designing networks is considered one of the most convenient and effective. The algorithm of this application is based on the use of the Altshul formula. The peculiarity of the program is that it copes well with both the calculation of natural ventilation and mechanical ventilation.
Since the software is constantly updated, it is worth noting that last edition The application is also able to carry out such work as aerodynamic calculations of the resistance of the entire ventilation system. It can also effectively calculate other additional parameters that will help in the selection of preliminary equipment. In order to make these calculations, the program will need data such as the air flow at the beginning and end of the system, as well as the length of the main room duct.
Since it takes a long time to manually calculate all this and you have to break the calculations into stages, this application will provide significant support and save a lot of time.
Sanitary standards
Another option for calculating ventilation is according to sanitary standards. Similar calculations are carried out for public and administrative facilities. In order to make correct calculations, it is necessary to know the average number of people who will constantly be inside the building. If we talk about permanent consumers of air inside, then they need about 60 cubic meters per hour per one. But since temporary persons also visit public facilities, they must also be taken into account. The amount of air consumed by such a person is about 20 cubic meters per hour.
If all calculations are carried out based on the initial data from the tables, then when the final results are obtained, it will become clearly visible that the amount of air coming from the street is much greater than that consumed inside the building. In such situations, most often resort to the most simple solution- extracts of approximately 195 cubic meters per hour. In most cases, adding such a network will create an acceptable balance for the existence of the entire ventilation system.
The design of ventilation of a residential, public or industrial building takes place in several stages. Air exchange is determined on the basis of regulatory data, the equipment used and the individual wishes of the customer. The scope of the project depends on the type of building: a one-story residential building or apartment is calculated quickly, with a minimum number of formulas, and serious work is required for a production facility. The method for calculating ventilation is strictly regulated, and the initial data are prescribed in SNiP, GOST and SP.
The selection of the optimal air exchange system in terms of power and cost takes place step by step. The order of design is very important, since the efficiency of the final product depends on its observance:
- Determining the type of ventilation system. The designer analyzes the source data. If you want to ventilate a small living space, then the choice falls on the supply and exhaust system with a natural impulse. This will be enough when the air flow is small, there are no harmful impurities. If it is required to calculate a large ventilation complex for a factory or a public building, then preference is given to mechanical ventilation with the function of heating / cooling the supply, and, if necessary, with the calculation of hazards.
- Outlier analysis. This includes: thermal energy from lighting fixtures and machine tools; fumes from machine tools; emissions (gases, chemicals, heavy metals).
- Calculation of air exchange. The task of ventilation systems is to remove excess heat, moisture, impurities from the premises with an equilibrium or slightly different supply of fresh air. For this, the air exchange rate is determined, according to which the equipment is selected.
- Equipment selection. It is produced according to the obtained parameters: the required volume of air for supply / exhaust; indoor temperature and humidity; the presence of harmful emissions, ventilation units or ready-made multi-complexes are selected. The most important of the parameters is the volume of air required to maintain the design expansion rate. Filters, heaters, recuperators, air conditioners and hydraulic pumps are included as additional network devices that ensure air quality.
Emission calculation
The volume of air exchange and the intensity of the system depends on these two parameters:
- Norms, requirements and recommendations prescribed in SNiP 41-01-2003 "Heating, ventilation and air conditioning", as well as other, more highly specialized regulatory documentation.
- actual emissions. Calculated by special formulas for each source, and are shown in the table:
|
Heat dissipation, J |
||
| Motor electric | N – engine power at nominal value, W; K1 - loading factor 0.7-0.9 k2η - coefficient of work at one time 0.5-1. |
|
| Lighting devices | ||
| Human | n is the estimated number of people for this room; q is the amount of heat that the body of one person releases. Depends on air temperature and intensity of work. |
|
| pool surface | 
|
V is the speed of air movement over the water surface, m/s; Т – water temperature, 0 С F – water surface area, m2 |
|
Moisture release, kg/h |
||
| Water surface, such as a pool | P is the mass transfer coefficient; F-surface area of evaporation, m 2 ; Pn1, Pn2 - partial pressures of saturated water vapor at a certain temperature of water and air in the room, Pa; RB - barometric pressure. Pa. |
|
| Wet floor | F - area wet surface floor, m 2; t s, t m - temperatures air masses, measured by dry / wet thermometer, 0 C. |
|
Using the data obtained as a result of calculating harmful emissions, the designer continues to calculate the parameters of the ventilation system.
Air exchange calculation
Experts use two main schemes:
- According to aggregated indicators. This method does not provide for harmful emissions such as heat and water. We will conditionally call it "Method No. 1".
- Method taking into account excess heat and moisture. Conditional name "Method No. 2".
Method number 1
Unit of measurement - m 3 / h ( Cubic Meters in hour). There are two simplified formulas:
L=K×V(m 3 /h); L \u003d Z × n (m 3 / h), where
K is the air exchange rate. The ratio of the volume of supply for one hour, to the total air in the room, times per hour;
V is the volume of the room, m 3;
Z is the value of the specific air exchange per unit of rotation,
n is the number of units of measure.
The selection of ventilation grilles is carried out according to a special table. The selection also takes into account average speed passage of air through the channel.
Method number 2
The calculation takes into account the assimilation of heat and moisture. If in production or public building excess heat, then the formula is used:
where ΣQ is the sum of heat releases from all sources, W;
c is the thermal capacity of air, 1 kJ/(kg*K);
tyx is the temperature of the air directed to the exhaust, °С;
tnp - temperature of the air directed to the supply, ° С;
Extract air temperature:
where tp.3 is the normative temperature in working area, 0 С;
ψ - coefficient of temperature increase, depending on the measurement height, equal to 0.5-1.5 0 C / m;
H is the length of the arm from the floor to the middle of the hood, m.
When the technological process involves the release of a large amount of moisture, a different formula is used:
where G is the volume of moisture, kg/h;
dyx and dnp - water content per kilogram of dry air supply and exhaust.
There are several cases, described in more detail in the regulatory documentation, when the required air exchange is determined by the multiplicity:
k is the frequency of air changes in the room, once per hour;
V is the volume of the room, m 3.
Section calculation
Square cross section air duct is measured in m 2. It can be calculated using the formula:
where v is the speed of air masses inside the channel, m/s.
It differs for the main air ducts 6-12 m/s and side appendages no more than 8 m/s. Quadrature affects throughput channel, the load on it, as well as the noise level and installation method.
Pressure loss calculation
The walls of the air duct are not smooth, and the internal cavity is not filled with vacuum, so part of the energy of the air masses during movement is lost to overcome these resistances. The amount of loss is calculated by the formula:
where ג is friction resistance, is defined as:
The formulas above are correct for channels round section. If the duct is square or rectangular, then there is a formula for converting to the diameter equivalent:
where a,b are the dimensions of the sides of the channel, m.
Head and motor power
The air pressure from the blades H must fully compensate for the pressure loss P, while creating the calculated dynamic P d at the outlet.
Power electric motor fan:
Selection of a heater
Often heating is integrated into the ventilation system. For this, heaters are used, as well as the recycling method. Device selection is carried out according to two parameters:
- Q in - limiting consumption of thermal energy, W / h;
- F k - determination of the heating surface for the heater.
Calculation of gravitational pressure
Applies only to natural system ventilation. With its help, its performance is determined without mechanical stimulation.
Equipment selection
Based on the data obtained on air exchange, the shape and size of the cross-section of air ducts and grilles, the amount of energy for heating, the main equipment is selected, as well as fittings, a deflector, adapters and other related parts. Fans are selected with a power reserve for peak periods of operation, air ducts are selected taking into account the aggressiveness of the environment and ventilation volumes, and heaters and recuperators are selected based on the thermal demands of the system.
Design errors
At the stage of creating a project, errors and shortcomings are often encountered. This may be reverse or insufficient traction, blowing out ( upper floors multi-storey residential buildings) and other issues. Some of them can be solved even after the installation is completed, with the help of additional installations.
A vivid example of a low-skilled calculation is insufficient draft at the exhaust from the production room without particularly harmful emissions. Let's say the ventilation duct ends with a round shaft, rising above the roof by 2,000 - 2,500 mm. Raising it higher is not always possible and advisable, and in such cases the principle of flare emission is used. A tip with a smaller diameter of the working hole is installed in the upper part of the round ventilation shaft. An artificial narrowing of the cross section is created, which affects the rate of gas release into the atmosphere - it increases many times over.
The method of calculating ventilation allows you to get a high-quality internal environment, correctly assessing the negative factors that worsen it. Mega.ru employs professional designers engineering systems any complexity. We provide services in Moscow and neighboring regions. The company is also successfully engaged in remote collaboration. All methods of communication are indicated on the page, please contact.
The quality of the air environment in the workshops is regulated by law, the standards are set in SNiP and TB. In most facilities, effective air exchange cannot be generated by a natural system, and equipment must be installed. It is important to achieve normative indicators. For this, the calculation supply and exhaust ventilation production premises.
The regulations provide different kinds pollution:
- excess heat from the operation of machines and mechanisms;
- fumes containing harmful substances;
- excess moisture;
- various gases;
- human secretions.
The calculation method offers an analysis for each type of pollution. The results are not summarized, and the largest value is taken into work. So, if in production the maximum volume is needed to remove excess heat, it is this indicator that is taken for calculations technical parameters structures. Let us give an example of calculating the ventilation of a production facility with an area of 100 m 2.
Air exchange at an industrial site with an area of 100 m 2
In production, it must perform the following functions:
- remove harmful substances;
- clean the environment from pollution;
- remove excess moisture;
- remove harmful emissions from the building;
- regulate the temperature;
- form an inflow of a clean stream;
- depending on site conditions and weather conditions, heat humidify or cool the incoming air.
Since each function requires additional power from the ventilation structure, therefore, the choice of equipment should be made taking into account all indicators.
Local exhaust
If in the technological processes of production at one of the sites emissions of harmful substances occur, then next to the source, according to the regulations, it is necessary to install a local exhaust. So the removal will be more effective.
Most often, such a source is technological tanks. For such objects, special installations are used - suction in the form of umbrellas. Its dimensions and power are calculated using the following parameters:
- source dimensions depending on the shape: side length (a*b) or diameter (d);
- flow velocity in the source zone (vv);
- suction speed of the unit (vz);
- suction height above the tank (z).
The sides of a rectangular suction are calculated by the formula:
A \u003d a + 0.8z,
where A is the suction side, a is the tank side, z is the distance between the source and the device.
The sides of a circular device are calculated using the formula:
D=d+0.8z,
where D is the diameter of the device, d is the diameter of the source, z is the distance between the suction and the reservoir.
Predominantly has the shape of a cone, the angle of which should not exceed 60 degrees. If the speed of the masses in the workshop is more than 0.4 m/s, then the device should be equipped with an apron. The amount of extract air is determined by the formula:
L=3600vz*Sa,
where L– air consumption in m3/h, vz – flow rate in the hood, Sa – suction working area.
Expert opinion
Ask an expertThe result must be taken into account in the design and calculations of the general exchange system.
General ventilation
When the calculation is done local exhaust, types and volumes of pollution, you can do mathematical analysis the required amount of air exchange. The simplest option is when there are no technological pollution on the site, and only human emissions are taken into account.
In this case, the goal is to achieve sanitary norms and purity production processes. The required volume for employees is calculated by the formula:
L=N*m,
where L is the amount of air in m 3 / hour, N is the number of employees, m is the volume of air per person per hour. The last parameter is normalized by SNiP and is 30 m 3 / hour - in a ventilated workshop, 60 m 3 / hour - in a closed one.
If harmful sources exist, then the task of the ventilation system is to reduce pollution to the maximum standards (MAC). Mathematical analysis is performed according to the formula:
O \u003d Mv \ (Ko - Kp),
where O is the air flow rate, Mw is the mass of harmful substances emitted into the air in 1 hour, Ko is the concentration of harmful substances, Kp is the number of pollutants in the inflow.
The influx of pollution is also calculated, for this I use the following formula:
L \u003d Mv / (ypom - yp),
where L is the volume of inflow in m3/h, Mw is the weight value of harmful substances emitted in the workshop in mg/h, yp is the specific concentration of pollutants in m3/h, yp is the concentration of pollutants from the supply air.
Calculation of general ventilation industrial premises does not depend on its area, other factors are important here. Mathematical analysis for a particular object is complex, it needs to take into account a lot of data and variables, you should use special literature and tables.
Forced ventilation
It is advisable to calculate industrial premises according to aggregated indicators, which express the flow of incoming air per unit volume of the room, per 1 person or 1 source of pollution. The standards set their own standards for various industries.
The formula is:
L=Vk
where L is the volume of supply masses in m 3 / hour, V is the volume of the room in m 3, k is the frequency of air exchange.
For a room with an area of 100 m 3 and a height of 3 meters for a 3-fold air change, you will need: 100 * 3 * 3 + = 900 m 3 / hour.
The calculation of exhaust ventilation of industrial premises is carried out after determining the required volumes of supply masses. Their parameters should be similar, so for an object with an area of 100 m 3 with a ceiling height of 3 meters and a three-fold exchange, the exhaust system should pump out the same 900 m 3 / hour.
Design includes many aspects. It all starts with compiling terms of reference, which determines the orientation of the object to the cardinal points, purpose, layout, materials of building structures, features of the technologies used and the mode of operation.
Computing volumes are large:
- climatic indicators;
- air exchange rate;
- distribution of air masses inside the building;
- determination of air ducts, including their shapes, location, capacities and other parameters.
Then a general scheme is drawn up, and the calculations continue. At this stage, the nominal pressure in the system and its loss, the noise level in production, the length of the duct system, the number of bends and other aspects are taken into account.
Summarizing
The correct mathematical analysis for determining the parameters of air exchange in production can only be done by a specialist using various data, variables and formulas.
Independent work will lead to errors, and as a result: violation of sanitary standards and technological processes. Therefore, if your company does not have a specialist with the proper level of qualifications, it is better to use the services of a specialized company.
Proper ventilation in the house significantly improves the quality of human life. With the wrong calculation of supply and exhaust ventilation there are a lot of problems - for a person with health, for a building with destruction.
Before starting construction, it is imperative and necessary to make calculations and, accordingly, apply them in the project.
PHYSICAL COMPONENTS OF CALCULATIONS
According to the way of work, at present, ventilation schemes are divided into:
- Exhaust. To remove used air.
- Supply. For clean air intake.
- Recovery. Supply and exhaust. Remove the used one and let in the clean one.
AT modern world ventilation schemes include various additional equipment:
- Devices for heating or cooling the supplied air.
- Filters for cleaning odors and impurities.
- Devices for humidification and air distribution in rooms.
When calculating ventilation, the following quantities are taken into account:
- Air consumption in cubic meters / hour.
- Pressure in air channels in atmospheres.
- Heater power in kWh.
- Cross-sectional area of air channels in sq.cm.
Exhaust ventilation calculation example
Before the beginning exhaust ventilation calculation it is necessary to study the SN and P (System of Norms and Rules) devices of ventilation systems. According to CH and P, the amount of air needed for one person depends on his activity.
Little activity - 20 cubic meters / hour. Average - 40 kb.m./h. High - 60 kb.m./h. Next, we take into account the number of people and the volume of the room.
In addition, you need to know the multiplicity - a complete exchange of air for an hour. For the bedroom, it is equal to one, for household rooms– 2, for kitchens, bathrooms and utility rooms – 3.
For example - calculation of exhaust ventilation rooms 20 sq.m.
Suppose two people live in a house, then:
V (volume) of the room is equal to: SxH, where H is the height of the room (standard 2.5 meters).
V \u003d S x H \u003d 20 x 2.5 \u003d 50 cubic meters.
In the same order, we calculate the performance of exhaust ventilation of the whole house.
Calculation of exhaust ventilation of industrial premises
At calculation of exhaust ventilation of the production room the multiplicity is 3.
Example: garage 6 x 4 x 2.5 = 60 cubic meters. 2 people work.
High activity - 60 cubic meters / hour x 2 \u003d 120 cubic meters / hour.
V - 60 cubic meters. x 3 (multiplicity) = 180 kb.m./h.
We choose more - 180 cubic meters / hour.
As a rule, unified ventilation systems, for ease of installation, are divided into:
- 100 - 500 cubic meters / hour. - apartment.
- 1000 - 2000 cubic meters / hour. - for houses and estates.
- 1000 - 10000 cubic meters / hour. – for factory and industrial facilities.
Calculation of supply and exhaust ventilation
AIR HEATER
Under climate conditions middle lane, the air entering the room must be heated. For this, set supply ventilation with incoming air heating.
Heating of the coolant is carried out in various ways - with an electric heater, the intake of air masses near the battery or furnace heating. According to SN and P, the temperature of the incoming air must be at least 18 degrees. celsius.
Accordingly, the power of the air heater is calculated depending on the lowest (in the given region) outdoor temperature. The formula for calculating the maximum temperature for heating a room with an air heater:
N / V x 2.98 where 2.98 is a constant.
Example: air consumption - 180 cubic meters / hour. (garage). N = 2 kW.
Thus, the garage can be heated up to 18 degrees. At outside temperature minus 15 degrees.
PRESSURE AND SECTION
The pressure and, accordingly, the speed of movement of air masses is affected by the cross-sectional area of the channels, as well as their configuration, the power of the electric fan and the number of transitions.
When calculating the channel diameter, the following values are empirically taken:
- For residential premises - 5.5 sq.cm. per 1 sq.m. area.
- For a garage and other industrial premises - 17.5 sq.cm. per 1 sq.m.
At the same time, flow rates of 2.4 - 4.2 m / s are achieved.
ABOUT ELECTRICITY CONSUMPTION
Electricity consumption directly depends on the duration of the electric heater operation, and the time is a function of the ambient temperature. Usually, the air needs to be heated in the cold season, sometimes in the summer on cool nights. For the calculation, the formula is used:
S = (T1 x L x d x c x 16 + T2 x L x c x n x 8) x N/1000
In this formula:
S is the amount of electricity.
T1 is the maximum daily temperature.
T2 is the minimum night temperature.
L - performance cubic meters / hour.
c - volumetric heat capacity of air - 0.336 W x hour / kb.m. / deg.c. The parameter depends on pressure, humidity and air temperature.
d is the price of electricity during the day.
n is the price of electricity at night.
N is the number of days in a month.
Thus, if you adhere to sanitary standards, the cost of ventilation increases significantly, but the comfort of residents improves. Therefore, when installing a ventilation system, it is advisable to find a compromise between price and quality.