Drawing of a room under combined lighting. Course work: Calculation of natural lighting. Natural Light Design

Natural light is most favorable for vision, since sunlight is necessary for normal human life. Visible rays of the solar spectrum (400-760 microns) provide the function of vision, determine the natural biorhythm of the body, have a positive effect on emotions and the intensity of metabolic processes; ultraviolet spectrum (290-400 microns) - stimulates the processes of metabolism, hematopoiesis, tissue regeneration and has an antirachitic (vitamin D synthesis) and bactericidal effect.

All rooms with constant occupancy should, as a rule, have natural light.

Natural lighting of the premises is created due to direct, diffused and reflected sunlight. It can be side, top, combined. Side lighting - through light openings in the external walls, top lighting - through light openings in the covering and lanterns, and combined lighting - in external walls and coverings.

The most hygienic is side lighting penetrating through windows, since overhead light with the same glazing area creates less illumination in the room; in addition, light openings and lanterns located in the ceiling are less convenient for cleaning and require special devices for this purpose. It is possible to use secondary lighting, i.e. lighting through glazed partitions from an adjacent room equipped with windows. However, it does not meet hygienic requirements and is allowed only in such areas as corridors, wardrobes, bathrooms, showers, utility rooms, and washing departments.

The design of natural lighting in buildings should be based on a detailed study of technological or other processes carried out indoors, as well as on the light-climatic features of the territory. This takes into account:

Characteristics of visual work; location of the building on the light climate map;

Required uniformity of natural light;

Equipment location;

The desired direction of incidence of the light flux on the working surface;

Duration of use of natural light during the day;

The need for protection from the glare of direct sunlight.

The following are used as hygienic indicators of natural light in premises:

Natural illumination coefficient (NLC) - the ratio of natural illumination indoors in control points measurements (at least 5) to the illumination outside the building (%). There are two groups of methods for determining KEO - instrumental and calculated.

In rooms with side lighting, the minimum value of the coefficient is normalized, and in rooms with overhead and combined lighting - the average value. For example, KEO in trading floors with side lighting should be 0.4-0.5%, with top lighting - 2%.

For enterprises Catering when designing side natural lighting, KEO should be: for halls, buffets - 0.4-0.5%; hot, cold, confectionery, pre-cooking and procurement shops - 0.8-1%; washing kitchen and tableware - 0.4-0.5%.

Luminous coefficient is the ratio of the area of the glazed surface of windows to the floor area. In industrial, commercial and administrative premises it should be at least -1:8, in domestic premises - 1:10.

However, this coefficient does not take into account climatic conditions, architectural features buildings and other factors affecting lighting intensity. Thus, the intensity of natural light largely depends on the design and location of windows, their orientation to the cardinal directions, and the shading of windows by nearby buildings and green spaces.

The angle of incidence is the angle formed by two lines, one of which runs from the workplace to the upper edge of the glazed part of the window opening, the other - horizontally from the workplace to the window. The angle of incidence decreases as you move away from the window. It is believed that for normal illumination by natural light, the angle of incidence should be at least 27o. The higher the window, the greater the angle of incidence.

Hole angle is the angle formed by two lines, one of which connects workplace with the top edge of the window, the other with the highest point of the light-obscuring object located in front of the window (opposing building, tree, etc.). With such darkness, the illumination in the room may be unsatisfactory, although the angle of incidence and luminous coefficient are quite sufficient. The hole angle must be at least 5°.

The illumination of the premises is directly dependent on the number, shape and size of windows, as well as on the quality and cleanliness of the glass.

Dirty glass with double glazing reduces natural light to 50-70%, smooth glass retains 6-10% of light, frosted glass - 60%, frozen glass - up to 80%.

The illumination of rooms is affected by the color of the walls: white reflects up to 80% sun rays, gray and yellow - 40%, and blue and green - 10-17%.

For best use light flow entering the room, walls, ceilings, and equipment must be painted in bright hues. Particularly important is the light coloring of window frames, ceilings, upper parts walls that provide maximum reflected light rays.

The cluttering of light openings sharply reduces the natural illumination of the premises. Therefore, at enterprises it is prohibited to fill windows with equipment, products, containers both inside and outside the building, as well as to replace glass with plywood, cardboard, etc.

In warehouses, lighting is usually not provided, and in some cases it is undesirable (for example, in pantries for storing vegetables), and is not allowed (in refrigeration chambers). However, natural lighting is advisable for storing flour, cereals, pasta, food concentrates, and dried fruits.

In case of insufficient natural light, combined lighting is allowed, in which natural and artificial light are used simultaneously.

Methods for proper planning of natural lighting

But knowing the types of natural lighting, we are not one step closer to uncovering the question of how to organize correct lighting at home? To answer this, let us look at the main stages of planning step by step.

Standards for natural lighting of buildings

In order to properly plan lighting, we first of all must answer the question, what should it be? The answer to this question is given to us by SNiP 23 - 05 - 95, which establishes KEO standards for industrial, residential and public buildings.

KEO is the natural light coefficient. It is the ratio between the level of natural light at a certain point in the house and the illumination outside the room.
The optimality of this parameter was calculated by research institutes and summarized in a table, which has become the norm in design. But in order to use this table we need to know our latitude.

From the lessons of BZD and geography, you must remember that the further south you go, the higher the intensity of the solar flux. Therefore, the entire territory of our country was divided into five light climate zones, each of which has two subspecies.
Knowing our light climate zone, we can finally determine the KEO we need. For residential buildings it ranges from 0.2 to 0.5. Moreover, the further south you go, the smaller the KEO.
This is again due to geography. After all, the further south you go, the higher the outdoor illumination. And KEO is the ratio of illumination outside the room and inside it. Accordingly, to create the same level of illumination for houses in the south and north, the latter will have to make more efforts.

To move on, we need to find out where is this point in the house for which we will determine the level of illumination? The answer to this question is given to us by clauses 5.4 - 5.6 SNiP 23 - 05 -95.
According to them, with two-way side lighting of residential premises, the normalized point is the center of the room. With one-way side lighting, the normalized point is a plane one meter from the wall opposite the window. In other rooms, the normalized point is the center of the room.

Note! For one-, two- and three-room apartments This calculation is made for one living room. In a four-room apartment, this calculation is made for two rooms.

For overhead and combined lighting, the normalized point is a plane one meter from the darkest walls. This standard also applies to industrial premises.
But everything that we have given above is prescribed for use in residential and public buildings. With production, everything is a little more complicated. The fact is that production is different. On some I process meter-long workpieces, while on others I deal with microcircuits.
Based on this, all types of work were divided into eight classes depending on the level of visual work. Where products smaller than 0.15 mm are processed, they were assigned to the first group, and where accuracy is not particularly needed, they were assigned to the eighth. And here's for industrial enterprises KEO is selected based on the level of visual work.

Selecting window systems for a building

Natural light will enter our building through the windows. Therefore, knowing the standards that we need to comply with, we can move on to choosing windows.

The very first task is choosing window systems. That is, we must decide what kind of lighting we will have - top, side or combined in each room. To answer this question, you need to take into account the architectural structure of the building, its geographical location, the materials used, the thermal efficiency of the house, and of course the price will play an important role.
If you opt for overhead lighting, then you can use so-called skylights or skylights. These are special structures that often, in addition to light, also provide ventilation for buildings.
Light aeration lanterns in most cases have a rectangular shape. This is due to ease of installation. At the same time, the triangular shape is considered the most successful in terms of lighting. But for triangular skylights there are practically no reliable systems for raising windows for ventilation.
Light aeration lamps are usually installed above industrial buildings with high internal heat generation, or on buildings located in southern latitudes, as in the video. This is due to the large heat losses of such window systems.

	Rectangular aeration lanterns are recommended for use in II-IV climatic zone. Moreover, if the installation is carried out in areas south of 55° latitude, then the orientation of the lantern should be south and north. Such lamps should be used in buildings with excess sensible heat above 23 W/m 2, and with a level of visual performance of IV-VII category.
	Trapezoidal aeration lanterns are designed for the first climate zone. They are used for buildings in which class II-IV visual work is performed and with excess sensible heat above 23 W/m 2.
	It is recommended to install skylights in climate zones I-IV. In this case, when buildings are located south of 55 0, diffuse or heat-protected glass should be used as light transmitting materials. It is used for buildings with excess sensible heat less than 23 W/m2 and for all classes of visual work. It is important to note that the lights must be evenly spaced across the entire roof area.
	A skylight with a light-conducting shaft can be used for all climatic zones. It is usually used for buildings with air-conditioned air and a small range of temperature differences (for example, it is quite possible to install it yourself in residential buildings), as well as for areas where class II-VI work is performed. They are widely used in buildings with suspended ceilings.

Rooflights have recently become increasingly widespread both in production and in residential construction. This is due to the ease of installation of such systems and a fairly comfortable cost. The heat losses of such window systems are not so great, which allows them to be successfully used in northern latitudes.

Note! To eliminate the possibility of injury to a person, all horizontal and inclined surfaces of vertical lighting must have special grids. They are necessary to prevent falling glass fragments.

If you decide to use natural side-type room lighting, then SNiP II-4-79 recommends giving preference to standard-type window systems. For such systems, all the necessary calculations have already been made and there are even recommendations. You can see these recommendations in the table below.

For side natural lighting important aspect is the shading of window systems from adjacent buildings. This must be taken into account when making calculations.

For buildings in which the wall opposite the window is located at a considerable distance, multi-tiered window systems are often installed. But it should be remembered that the height of one tier should not exceed 7.2 meters.
A very important aspect when choosing window systems is their correct orientation to the cardinal points. After all, it’s no secret that windows facing south provide significantly more light. This should be used to the maximum in buildings constructed in northern latitudes. At the same time, for buildings built in southern latitudes, it is recommended to orient windows to the north and west.

This will not only make it possible to use daylight more efficiently, but also reduce costs. Indeed, for buildings in southern latitudes, special light-blocking devices are installed to limit the glare of the sun, and with the correct orientation of the windows this can be avoided.

Combination of KEO standards and illumination standards

But KEO standards are not designed for every type of building. Sometimes it may happen that, according to KEO standards, the illumination is sufficient, but the illumination standards for the workplace are not met.

This lack of natural light can be compensated by creating combined lighting, or linked through critical outdoor lighting.

Critical outdoor illumination is the natural illumination in an open area equal to the standardized value of artificial lighting. This value allows you to bring the KEO in accordance with the requirements for artificial lighting.
For this, the formula E n =0.01eE cr is used, where E n is the standardized value of illumination, e is the selected KEO standard, and E cr is our critical external illumination.

But even this method does not always allow achieving the required standards. After all, natural light indicators do not always make it possible to achieve standardized values of workplace illumination. First of all, this applies to buildings located in northern latitudes, where the intensity of the light flux is lower and heat losses they don't give you the option to install a large number of windows

Especially for finding the golden mean, there is a so-called calculation of reduced costs for natural lighting. It allows you to determine whether it is more profitable for a building to create high-quality natural lighting or to limit it to combined, or perhaps even artificial, lighting.

Conclusion

Rooms without natural light are not nearly as comfortable as buildings with direct sunlight. Therefore, if such a possibility exists, natural light should definitely be created for any buildings and structures.

Of course, the issue of natural lighting is much more voluminous and multifaceted, but we have fully covered the main aspects of natural lighting in buildings, and we really hope that this will help you in making the right choice lighting for home or business.

The design of natural lighting in buildings should be based on the study of labor processes performed indoors, as well as on the light-climatic features of the building construction site. In this case, the following parameters must be defined:

characteristics and category of visual work;

group of the administrative district in which the construction of the building is proposed;

the normalized value of KEO, taking into account the nature of visual work and the light-climatic features of the location of the buildings;

required uniformity of natural light;

duration of use of natural light during the day for different months year, taking into account the purpose of the room, operating mode and light climate of the area;

the need to protect the premises from the glare of sunlight.

Designing natural lighting for a building should be done in the following sequence:

determination of requirements for natural light premises;

choice of lighting systems;

selection of types of light openings and light-transmitting materials;

choosing means to limit the glare of direct sunlight;

taking into account the orientation of the building and light openings on the sides of the horizon;

performing a preliminary calculation of the natural lighting of the premises (determining the required area of light openings);

clarification of the parameters of light openings and rooms;

performing a verification calculation of the natural lighting of the premises;

identification of rooms, zones and areas that have insufficient natural lighting according to standards;

determination of requirements for additional artificial lighting of rooms, zones and areas with insufficient natural light;

determination of requirements for the operation of light openings;

making the necessary adjustments to the natural lighting design and repeating the verification calculation (if necessary).

The natural lighting system of a building (side, top or combined) should be selected taking into account the following factors: the purpose and adopted architectural, planning, volumetric and structural design of the building;

requirements for natural lighting of premises arising from the peculiarities of production technology and visual work; climatic and light-climatic features of the construction site; efficiency of natural lighting (in terms of energy costs).

Overhead and combined natural lighting should be used mainly in one-story public buildings of large area (indoor markets, stadiums, exhibition pavilions, etc.).

Lateral natural lighting should be used in multi-story public and residential buildings, one-story residential buildings, as well as in one-story public buildings in which the ratio of the depth of the premises to the height of the upper edge of the light opening above the conventional working surface does not exceed 8.

When choosing light openings and light-transmitting materials, you should consider:

requirements for natural lighting of premises; purpose, volumetric-spatial and constructive solution building; orientation of the building along the horizon; climatic and light climatic features of the construction site;

the need to protect premises from insolation; degree of air pollution.

When designing side natural lighting, the shading created by opposing buildings should be taken into account. Shading is taken into account in accordance with the section of this Code of Rules.

The choice of devices for protection against the glare of direct sunlight should be made taking into account:

orientation of light openings on the sides of the horizon;

the direction of the sun's rays relative to a person in the room who has a fixed line of sight (student at his desk, draftsman at the drawing board, etc.);

working hours of the day and year, depending on the purpose of the premises;

differences between solar time, according to which solar maps are constructed, and maternity time adopted on the territory of the Russian Federation.

When choosing products to protect against the glare of direct sunlight, you should be guided by the requirements building codes and rules for the design of residential and public buildings (SNiP 31-01, SNiP 2.08.02).

During a single-shift work (educational) process and when operating premises mainly in the first half of the day (for example, lecture halls), when the premises are oriented towards the western quarter of the horizon, the use of sunscreen is not necessary.

In some cases, for example, when conducting examinations, there is a need for an objective assessment of the natural lighting of premises based on KEO measurements using lux meters. Modern photometric devices have silicon photocells as sensors, equipped with yellow and green light filters that correct their spectral sensitivity according to the spectral sensitivity of the human eye, as well as special nozzles cosine correction. Correction of spectral sensitivity and cosine can also be done using a computer. Selenium photocells are used less frequently, as they are short-lived and require constant calibration on a photometric bench.

Their sensitivity depends on air temperature. Considering that all calculations and KEO standards have the cloudy sky of the ICO as the main assumption, KEO measurements can only be made under continuous cloudiness of ten points. However, there may be exceptions, for example in the case of KEO measurements in the presence of light guides or light guiding devices. In this case, the KEO value becomes conditional. And when measuring outdoor illumination, it is necessary to shield the direct light of the sun.

When calculating the efficiency of such devices, the total illumination from the direct sun and sky (Eq) should be taken as the value of external illumination.

To measure KEO, a journal of field measurements is prepared, which indicates the place, time and weather during measurements, instruments, proportionality coefficient between the readings of lux meters (in the case of low-quality instruments), geometric parameters rooms and light openings, reflection coefficients of internal and adjacent external surfaces, type of filling of the opening and its contamination. The safety factor is determined by dividing the light meter readings when the sensor is positioned in a vertical plane outside the glass and inside behind the glass. The reflectance of surfaces is measured using a reflexometer. In addition to this data, the journal must contain tables for recording measurement results. The results of indoor measurements, usually at five points on the working surface, pre-marked along a characteristic section, are synchronized in time with the results of outdoor light measurements taken on an open, unshaded area, preferably on the roof of a building. For this purpose, external illumination is measured every minute. Next to each result, the measurement time is recorded. Internal illumination at the designated points is measured at the same time. The time of each measurement is also recorded. When filling out the measurement log, in the “external illumination” column, a result is selected that coincides in time with the result of measuring internal illumination at a given point. Measurements at each point should be carried out at least twice to eliminate random errors. The results obtained must be averaged.

KEO as a percentage is determined by dividing the reading of the internal lux meter by the reading of the external lux meter and multiplying by 100. If there is a “calibration” coefficient k between the readings of the internal lux meter, determine by the formula

Introduction

Premises with constant occupancy should have natural light.

Natural lighting is the illumination of premises by direct or reflected light penetrating through light openings in external enclosing structures. Natural lighting should be provided, as a rule, in rooms with constant occupancy. Without natural lighting, it is allowed to design certain types of industrial premises in accordance with the Sanitary Standards for the Design of Industrial Enterprises.

Types of natural lighting

The following types of natural indoor lighting are distinguished:

· lateral one-sided - when the light openings are located in one of the external walls of the room,

Figure 1 - Lateral one-way natural lighting

· lateral - light openings in two opposite external walls of the room,

Figure 2 - Lateral natural lighting

· upper - when lanterns and light openings in the covering, as well as light openings in the walls of the difference building heights,

· combined - light openings provided for side (top and side) and overhead lighting.

The principle of normalizing natural light

Natural lighting is used for general lighting of production and utility rooms. It is created by the radiant energy of the sun and has the most beneficial effect on the human body. Using this type of lighting, one should take into account meteorological conditions and their changes during the day and periods of the year in a given area. This is necessary in order to know how much natural light will enter the room through the light openings of the building: windows - with side lighting, light lanterns the upper floors of the building - with overhead lighting. With combined natural lighting, side lighting is added to the overhead lighting.

Premises with constant occupancy should have natural light. Established by calculation The dimensions of light openings can be changed by +5, -10%.

The unevenness of natural lighting in industrial and public buildings with overhead or overhead and natural side lighting and main rooms for children and adolescents with side lighting should not exceed 3:1.

Sun protection devices in public and residential buildings should be provided in accordance with the chapters of SNiP on the design of these buildings, as well as with the chapters on building heating engineering.

The quality of lighting with natural light is characterized by the coefficient of natural illumination to eo, which is the ratio of illumination on a horizontal surface indoors to the simultaneous horizontal illumination outside,

where E in is the horizontal illumination indoors in lux;

E n - horizontal illumination outside in lux.

With side lighting, the minimum value of the natural illumination coefficient is normalized - to eo min, and with overhead and combined lighting - its average value - to eo avg. The method for calculating the natural light factor is given in Sanitary standards design of industrial enterprises.

In order to create the most favorable working conditions, natural light standards have been established. In cases where natural light is insufficient, work surfaces should be additionally illuminated with artificial light. Mixed lighting is allowed provided additional lighting is provided only for working surfaces in general natural light.

Building codes and regulations (SNiP 23-05-95) set the coefficients of natural illumination of industrial premises depending on the nature of the work in terms of accuracy.

To maintain the necessary illumination of the premises, the standards provide for mandatory cleaning of windows and skylights from 3 times a year to 4 times a month. In addition, walls and equipment should be systematically cleaned and painted in light colors.

The standards for natural lighting of industrial buildings, reduced to the K.E.O. standardization, are presented in SNiP 23-05-95. To facilitate the regulation of workplace illumination, all visual work is divided into eight ranks according to the degree of accuracy.

SNiP 23-05-95 establish the required value of K.E.O. depending on the accuracy of the work, the type of lighting and the geographical location of production. The territory of Russia is divided into five light belts, for which the values of K.E.O. are determined by the formula:

where N is the group number of the administrative-territorial region according to the provision of natural light;

The value of the natural illumination coefficient, selected according to SNiP 23-05-95, depending on the characteristics of visual work in a given room and the natural lighting system.

Light climate coefficient, which is found according to SNiP tables depending on the type of light openings, their orientation along the horizon and the group number of the administrative district.

To determine whether natural illumination in a production room corresponds to the required standards, illumination is measured with overhead and combined lighting - at various points in the room, followed by averaging; with side-by-side lighting - in the least illuminated workplaces. At the same time, the external illumination and the calculated K.E.O. are measured. compared with the norm.

Natural Light Design

1. The design of natural lighting of buildings should be based on the study of labor processes performed indoors, as well as on the light-climatic features of the building construction site. In this case, the following parameters must be defined:

characteristics and category of visual work;

group of the administrative district in which the construction of the building is proposed;

the normalized value of KEO, taking into account the nature of visual work and the light-climatic features of the location of the buildings;

required uniformity of natural light;

the duration of use of natural light during the day for different months of the year, taking into account the purpose of the room, operating mode and light climate of the area;

the need to protect the premises from the glare of sunlight.

2. Design of natural lighting of a building should be carried out in the following sequence:

determination of requirements for natural lighting of premises;