While reading the text, try to visualize everything that is written. This will help you not get confused in the endless colors and shades, and will also help you understand the article more accurately. In general, go ahead and sing! By the way, who plays what? Please write in the comments - it’s interesting to know what people listen to while surfing the Internet.
Dawn
At dawn the lighting changes very quickly. Natural light has a bluish tint just before sunrise. And if the sky is clear at this time, the effect of a red sunset may be observed. In nature, a combination of high stratus or cirrus clouds with low-lying fog is often found. In such conditions, there is a transition of sunlight from directed from bottom to top to general more diffused light, in which shadows are blurred. At negative temperature the effect is more pronounced.
At dawn, you get excellent pictures of plants, open landscapes, ponds, and east-facing churches. Often fog spreads in the lowlands, near the water surface. Valley landscapes look very impressive when photographed from a high point in an eastern direction. It is often at dawn that scenes with equipment, metal structures and any other objects that have a glossy shiny surface are filmed. In natural light, such surfaces and the reflections from them look simply magnificent.
Photographer: Slava Stepanov.
The quality of light in the mountains is determined by location. If the terrain hides the sunrise, it is almost impossible to get interesting lighting effects. It should also be mentioned that dawn is most often calm. This helps to get perfect shots of smooth surfaces of bodies of water.
Natural light in the morning
After sunrise the light changes very quickly. In warm months, the sun can dispel fog or haze, in cold periods it can create it (as a result of evaporation of frost). Weak evaporations from ponds, rivers, and wet roads can be effective. If it rained at night, then in the morning the streets are wet and the plants are dim in normal conditions, will sparkle with many bright sparkles.
As the distance increases, the landscape blurs and brightens. This can be used to convey the 3rd dimension. During this period of the day, the color of the lighting changes from warm, bright yellow with golden notes to a warmish-neutral tone. In pictures taken in the morning, human skin looks very smooth. The fact is that at night our skin tightens, and in the morning the face seems refreshed - the main thing is to wash it properly.
Photographer: Maria Kilina.
An hour later, the sun has risen, creating ideal lighting for photography. Professional photographers often get up long before dawn in order to have time to prepare for the session and “catch” the optimal light. The weather forecast is almost irrelevant because morning weather is difficult to predict.
There are other reasons to wake up early and get to your shooting location in plenty of time. You will be able to independently monitor weather changes and, based on the position of the sun, understand at what time there will be optimal natural lighting for photographing specific scenes. It is advisable to keep appropriate records. Also do not forget that the observation results will only be valid for a specific time of year.
Noon
The time and duration of ideal light depends on the latitude of the area and the season. In northern regions, where the sun does not set but does not rise too high, this light is observed most of the night and all day. In temperate latitudes, suitable light remains for several hours. But do not forget that in this case the position of the luminary changes. In winter it can be low all day (I’ll talk about this in detail).
Maximum brightness occurs for four hours in the very middle of the day. In the hot summer there are also 4 ideal hours for photography. Two of them are in the afternoon, and two more in the morning. There is a dead period between them. At this time, there is a very high probability of getting overexposed in the photo.
Photographer: Ovchinnikova Elena.
In equatorial and tropical regions, natural light at midday is not suitable for photography. The sun is located high above your head and creates an annoying, blinding light that makes the surrounding landscapes expressionless.
People photography can only be done using fill light through direct additional lighting or reflectors. It is recommended to use light with a color temperature of approximately 5.2 thousand Kelvin.
Midday light in such regions can only be used to photograph canyons and gorges that are densely covered with vegetation. At other times of the day in similar corners sunlight misses. The presence of direct rays helps the photographer get bright, contrasting images.
Afternoon and evening
When heated during the day, the air absorbs moisture from water or soil. Therefore, in the 2nd half of the day, changes in the spectral composition (color) are observed. natural light, which are not always present in the morning. Warm air absorbs more moisture. Cooling as the sun moves toward sunset, it loses its ability to retain moisture. The latter condenses into invisible tiny drops, which remain in the form of a suspension. When the temperature drops sharply, it becomes foggy. This is especially true in maritime regions.
Usually the fog is very weak and visually noticeable availability of easy haze, which can “dim” the light. For this reason, summer afternoons can seem dull and gloomy, even if the sun is shining brightly. In photographs this is expressed by “suppressed” colors and tones. As the evening approaches, the situation improves as the sun's rays begin to break through the haze of dust and water particles to reveal an aerial perspective.
Photographer: Maria Kilina.
In the 2nd half summer day the air in the city may look grey. If you look at the city from an airplane, you will notice a haze of light bluish haze around it. It should be taken into account that dust and moisture scatter the rays of natural light. When the sun is high, red rays are absorbed and blue rays are scattered, raising the color temperature. A cold metallic blue appears in the photographs, looking unattractive.
The above partly explains how afternoon light differs from morning light. There are other factors, such as the characteristic orientation of building and other structures in various locations. The same gardens are located so as to capture sunlight as much as possible. Trees and plants take on their final shape, which depends on how the sun's rays hit them. But in general, morning light is more preferable than afternoon light.
Sunset
At sunset, a specific natural light is created, characteristic of the low position of the luminary, when the atmosphere allows the transmission of red long-wave radiation and reflects short-wave blue radiation. During the day, some of the red rays were absorbed by the haze, and the blue rays were scattered. Now the situation is reversed. The upper part of the sky remains blue because the angle of its illumination has changed. As a result, cool color combinations and smooth tonal gradients.
A sunset can become both a source of light and the subject of photography itself. In this case, we will consider only the quality of radiation characteristic of this time of day. At sunset, the sun's rays break through the haze or light clouds. Their color gradually warms up (the color temperature decreases).
Many photographers consider this state of the atmosphere to be the most favorable for conveying natural light in the evening and interesting in context color range. If there is a need to make adjustments, this can be done by using blue filters.
State Educational Institution of Higher Professional Education "Surgut State University"
Khanty-Mansiysk Autonomous Okrug– Ugra
Department of Life Safety
Course work
Topic: “Calculation of natural lighting”
Completed by: 04-42 group 5th year student
Faculty of Chemical Technology
Semenova Yulia Olegovna
Teacher:
Candidate of Chemical Sciences, Associate Professor
Andreeva Tatyana Sergeevna
The course work contains: 15 drawings, 9 tables, 2 sources used (including SP 23-102-2003 and SNiP 23-05-95), calculation formulas, calculations, plan and section of the room (sheet 1, sheet 2, format A 3).
Purpose of the work: determining the area of light openings, that is, the number and geometric dimensions of windows that provide the normalized value of KEO.
Object of study: office.
Volume of work: 41 pages.
Result of the work: the selected dimensions of the light opening meet the requirements of the standards for combined lighting of the office.
Introduction 4
Chapter 1. Types of natural lighting 5
Chapter 2. The principle of rationing natural light 6
Chapter 3. Designing natural lighting 9
Chapter 4. Calculation of natural lighting
4.1. Selecting daylight factor values 12
4.2. Preliminary calculation of the area of light openings and KEO with side lighting 13
4.3. Test calculation of KEO with side lighting 16
4.4. Preliminary calculation of the area of light openings and KEO at overhead lighting 19
4.5. Test calculation of KEO with overhead lighting 23
Chapter 5. Calculation of natural lighting in the office 29
Tables 32
Conclusion 39
References 40
Introduction
Premises with constant occupancy should have natural light.
Natural lighting - lighting of premises with 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
Distinguish the following types natural lighting of premises:
side one-sided - when the light openings are located in one of the external walls of the room,
Figure 1 - Lateral one-way natural lighting
side - 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 height difference of the building,
·combined - light openings provided for side (top and side) and top 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. When using this type of lighting, meteorological conditions and their changes during the day and periods of the year in a given area should be taken into account. This is necessary in order to know how much natural light will enter the room through arranged light openings of the building: windows - with side lighting, skylights of 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. The dimensions of light openings established by calculation can be changed by +5, -10%.
Unevenness of natural lighting in industrial and industrial premises 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 light 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 conditions labor standards for natural light 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 of only working surfaces with general natural lighting.
Building codes and regulations (SNiP 23-05-95) set the coefficients of natural illumination of industrial premises depending on the nature of the work and the degree 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 categories 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 the 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 district 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 region.
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; at the side - at 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 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;
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;
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;
performance preliminary calculation natural lighting of 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).
3. The natural lighting system of the building (side, top or combined) should be selected taking into account the following factors:
purpose and adopted architectural, planning, volumetric-spatial and constructive solution 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).
4. Overhead and combined natural lighting should be used mainly in one-story public buildings of large area (indoor markets, stadiums, exhibition pavilions, etc.).
5. 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.
6. When choosing light openings and light-transmitting materials, you should consider:
requirements for natural lighting of premises;
purpose, volumetric-spatial and structural design of the 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.
7. When designing side natural lighting, shading created by opposing buildings should be taken into account.
8. Translucent fillings of light openings in residential and public buildings are selected taking into account the requirements of SNiP 23-02.
9. For side natural lighting of public buildings with increased requirements for constant natural lighting and sun protection (for example, art galleries), light openings should be oriented towards the northern quarter of the horizon (N-NW-N-NE).
10. The selection of devices for protection from 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;
the difference between solar time, according to which solar maps are built, and maternity time adopted in the territory Russian Federation.
When choosing means to protect against the glare of direct sunlight, you should be guided by the requirements of building codes and regulations for the design of residential and public buildings (SNiP 31-01, SNiP 2.08.02).
11. 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.
Calculation of natural light
The purpose of calculating natural lighting is to determine the area of light openings, that is, the number and geometric dimensions of windows that provide the normalized KEO value.
Selecting KEO values
1. In accordance with SNiP 23-05, the territory of the Russian Federation is zoned into five groups of administrative districts according to light climate resources. The list of administrative districts included in the natural light supply groups is given in Table 1.
2. KEO values in residential and public buildings located in the first group of administrative districts are taken in accordance with SNiP 23-05.
3. KEO values in residential and public buildings located in the second, third, fourth and fifth groups of administrative districts are determined by the formula
e N = e n m N , (1)
Where N- number of the group of administrative districts according to Table 1;
e n- normalized value of KEO according to Appendix I SNiP 23-05;
m N- light climate coefficient, taken according to Table 2.
The values obtained using formula (1) should be rounded to tenths.
4. The dimensions and location of light openings in the room, as well as compliance with the requirements of the standards for natural lighting of premises, are determined by preliminary and verification calculations.
Preliminary calculation of the area of light openings and KEO with side lighting
1. A preliminary calculation of the size of light openings with side lighting without taking into account opposing buildings should be carried out using the graphs given for premises of residential buildings in Figure 3, for premises of public buildings - in Figure 4, for school classrooms - in Figure 5. The calculation should be made in following sequence:
Drawing 3 - Graph for determining the relative area of light openings A s.o /A p with side lighting of residential premises
Drawing 4 - Graph for determining the relative area of light openings A s.o /A p with side lighting of public buildings
Drawing 5 - Graph for determining the relative area of light openings A s.o /A p with side lighting of school classrooms
a) depending on the category of visual work or the purpose of the premises and the group of administrative districts for the light climate resources of the Russian Federation according to SNiP 23-05, determine the normalized value of KEO for the premises in question;
d P h 01 and attitude d P /h 01 ;
c) on the x-axis of the graph (Figures 3, 4 or 5) determine the point corresponding to a certain value d P /h 01, a vertical line is drawn through the found point until it intersects with the curve corresponding to the normalized KEO value. The ordinate of the intersection point determines the value A s.o /A p ;
d) dividing the found value A s.o /A p by 100 and multiplying by the floor area, find the area of light openings in m2.
2. In the case when the dimensions and location of light openings in the building design were chosen for architectural and construction reasons, a preliminary calculation of the KEO values in the premises should be made according to Figures 3-5 in the following sequence:
a) using construction drawings, find the total area of light openings (clear) A s.o and illuminated floor area of the room A p and determine the attitude A s.o /A p ;
b) determine the depth of the room d P, the height of the upper edge of the light openings above the conditional level work surface h 01 and attitude d P /h 01 ;
c) taking into account the type of premises, select the appropriate schedule (Figures 3, 4 or 5);
d) by values A s.o /A p And d P /h 01 on the graph find a point with the corresponding KEO value.
The graphs (Figures 3-5) were developed in relation to the most common dimensional layouts of premises in design practice and the standard solution for translucent structures - wooden paired opening frames.
Test calculation of KEO with side lighting
1. Check calculation of KEO Calculation of KEO should be carried out in the following sequence:
a) graph I (Figure 6) is superimposed on the cross section of the room so that its pole (center) 0 aligns with the design point A(Figure 8), and the bottom line of the graph is with a trace of the working surface;
b) according to graph I, count the number of rays passing through the cross section of the light opening from the sky n 1 and from the opposing building to the design point A ;
c) mark the numbers of semicircles on graph I that coincide with the middle WITH 1 section of the light opening through which the sky is visible from the calculated point, and with the middle WITH 2 sections of light opening through which the opposing building is visible from the calculated point (Figure 8);
d) schedule II (Figure 7) is superimposed on the floor plan so that its vertical axis and the horizontal, the number of which corresponds to the number of the concentric semicircle (point “c”), pass through the point WITH 1 (Figure 8);
e) count the number of rays P 2 according to schedule II, passing from the sky through the light opening on the floor plan to the design point A ;
f) determine the value of the geometric KEO, taking into account direct light from the sky;
g) schedule II is superimposed on the floor plan in such a way that its vertical axis and horizontal line, the number of which corresponds to the number of the concentric semicircle (point “c”), pass through the point WITH 2 ;
h) count the number of rays according to schedule II passing from the opposing building through the light opening on the floor plan to the calculated point A ;
i) determine the value of the geometric coefficient of natural illumination, taking into account the light reflected from the opposing building;
j) determine the value of the angle at which the middle of the sky section is visible from the calculated point on the cross section of the room (Figure 9);
k) based on the value of the angle and the specified parameters of the room and surrounding buildings, the values of the coefficients are determined qi , b f , k ZD , r O, And K h, and calculate the KEO value at the design point of the room.
Drawing 6- Graph I for calculating geometric KEO
Drawing 7 - Graph II for calculating geometric KEO
Notes
1 Graphs I and II are applicable only for rectangular light openings.
2 The plan and section of the room are made (drawn) on the same scale.
A- design point; 0 - pole of graph I; WITH 1 - the middle of the section of the light opening through which the sky is visible from the calculated point; WITH 2 - the middle of the section of the light opening through which the opposing building is visible from the calculated point
Drawing 8 - Example of using graph I to count the number of rays from the sky and the opposing building
Preliminary calculation of the area of light openings and KEO with overhead lighting
1. To preliminary calculate the area of light openings with overhead lighting, the following graphs should be used: for skylights with an opening depth (light shaft) of up to 0.7 m - according to Figure 9; for mine lights - according to Figures 10, 11; for rectangular, trapezoidal lanterns, sheds with vertical glazing and sheds with inclined glazing - according to Figure 12.
Table 1
| Fill type | Coefficient values K 1 for graphs in figures | |
| 1 | 2, 3 | |
| One layer of window glass in steel single blind sash | - | 1,26 |
| The same, in opening bindings | - | 1,05 |
| Single layer of window glass in wooden single opening sash | 1,13 | 1,05 |
| Three layers of window glass in separate-paired metal opening frames | - | 0,82 |
| The same, in wooden bindings | 0,63 | 0,59 |
| Two layers of window glass in steel double opening sashes | - | 0,75 |
| The same, in blind bindings | - | - |
| Double-glazed windows (two layers of glazing) in steel single opening frames* | - | 1,00 |
| The same, in blind bindings* | - | 1,15 |
| Double-glazed windows (three layers of glazing) in solid steel twin frames* | - | 1,00 |
| Hollow glass blocks | - | 0,70 |
| * When using other types of bindings (PVC, wood, etc.) coefficient K 1 is taken according to Table 3 before carrying out the appropriate tests. | ||
Area of light openings of lamps A s.f determined from the graphs in Figures 9-12 in the following sequence:
a) depending on the category of visual work or the purpose of the premises and group of administrative districts for the light climate resources of the Russian Federation according to SNiP 23-05;
b) on the ordinate of the graph, a point corresponding to the normalized value of KEO is determined, a horizontal line is drawn through the found point until it intersects with the corresponding curve of the graph (Figures 9-12), the value is determined from the abscissa of the intersection point A s.f /A p ;
c) dividing the value A s.f /A p by 100 and multiplying by the floor area, find the area of the light openings of the lamps in m2.
Preliminary calculation of KEO values in premises should be made using the graphs in Figures 9-12 in the following sequence:
a) using the construction drawings, find the total area of the light openings of the lamps A s.f, illuminated floor area of the room A p and determine the attitude A s.f /A p ;
b) taking into account the type of lantern, select the appropriate pattern (8, 10, 11 or 12);
c) in the selected picture through the abscissa point A s.f /A p draw a vertical line until it intersects with the corresponding graph; the ordinate of the intersection point will be equal to the calculated average value of the daylight factor e cf .
Drawing 9 - Graph for determining the average KEO value e cf in rooms with skylights with an opening depth of up to 0.7 m and dimensions in plan, m:
1 - 2.9x5.9; 2 3 - 1.5x1.7
Drawing 10 - Graph for determining the average KEO value e cf in public premises with shaft lamps with a light-conducting shaft depth of 3.50 m and plan dimensions, m:
1 - 2.9x5.9; 2 - 2.7x2.7; 2.9x2.9; 1.5x5.9; 3 - 1.5x1.7
Drawing 11 - Graph for determining the average KEO value e cf in public spaces with shaft lamps of diffuse light with a light-conducting shaft depth of 3.50 m and dimensions in plan, m:
1 - 2.9x5.9; 2 - 2.7x 2.7; 2.9x2.9; 1.5x5.9; 3 - 1.5x1.7
1 - trapezoidal lantern; 2 - shed having inclined glazing;
3 - rectangular lantern; 4 - a shed with vertical glazing
Drawing 12- Graph for determining the average KEO value e cp in public areas with lanterns
Test calculation of KEO with overhead lighting
The KEO calculation is carried out in the following sequence:
a) graph I (Figure 6) is applied to the cross section of the room so that the pole (center) 0 of the graph is aligned with the calculated point, and the bottom line of the graph is aligned with the trace of the working surface. Count the number of radially directed rays of graph I passing through the cross section of the first opening ( n 1) 1, second opening - ( n 1) 2, third opening - ( n 1) 3, etc.; at the same time, the numbers of semicircles that pass through the middle of the first, second, third openings, etc. are noted;
b) determine the angles , , etc. between the bottom line of graph I and the line connecting the pole (center) of graph I with the middle of the first, second, third openings, etc.;
c) schedule II (Figure 7) is applied to a longitudinal section of the room; in this case, the graph is positioned so that its vertical axis and horizontal, the number of which must correspond to the number of the semicircle on graph I, pass through the middle of the opening (point C).
Count the number of rays according to schedule II passing through the longitudinal section of the first opening ( n 2) 1, second opening - ( P 2) 2, third opening - ( n 2) 3, etc.;
d) calculate the value of the geometric KEO at the first point of the characteristic section of the room using the formula
Where R- number of light openings;
q- coefficient that takes into account the uneven brightness of the sky area visible from the first point, respectively, at angles ,, etc.;
e) repeat the calculations in accordance with points “a”, “b”, “c”, “d” for all points of the characteristic section of the room until N inclusive (where N- the number of points at which the KEO is calculated);
f) determine the average value of the geometric KEO;
g) based on the given parameters of the room and light openings, the values are determined r 2 , k f , ;
A verification calculation of KEO values at points of a characteristic section of a room with overhead lighting from skylights and mine lights should be performed according to the formula:
Where A f.v- area of the upper entrance hole of the lantern;
N f- number of lanterns;
q() is a coefficient that takes into account the uneven brightness of the cloudy sky of the ICO;
The angle between the straight line connecting the calculated point with the center of the lower hole of the lantern and the normal to this hole;
Average value of geometric KEO;
K With- light transmission coefficient of the lantern, determined for lanterns with diffuse reflection of the walls, and for lanterns with directional reflection of the walls -by value mine lantern light opening index i f ;
Drawing 13 - Graph for determining the coefficient q() depending on the angle
Drawing 14 K With lamps with diffuse reflection of the shaft walls
Drawing 15 - Graph for determining the light transmission coefficient Kc lanterns with directional reflection of the shaft walls at different meanings shaft wall diffuse reflection coefficient
K h- a calculated coefficient that takes into account the decrease in CEC and illumination during operation due to contamination and aging of translucent fillings in light openings, as well as a decrease in the reflective properties of room surfaces (safety factor).
Light opening index of a lantern with rectangular holes i f determined by the formula
Where A f.n.- area of the lower opening of the lantern, m2;
A f.v- area of the upper opening of the lantern, m2;
h s.f- height of the light-conducting shaft of the lantern, m.
R f.v , R f.n.- perimeter of the upper and lower openings of the lantern, respectively, m.
The same, with holes in the shape of a circle - according to the formula
i f = (r f.v + r f.n.) / 2h s.f , (5)
Where r f.v , r f.n.- the radius of the upper and lower holes of the lantern, respectively.
Calculate the value of the geometric KEO at the first point of the characteristic section of the room using the formula
Repeat the calculations for all points of the characteristic section of the room until N j inclusive (where N j- the number of points at which the KEO calculation is performed).
Determined by formula
The direct component KEO is sequentially calculated for all points using the formula
Determine the reflected component KEO, the value of which is the same for all points, according to the formula
. (9)
Calculation of natural lighting in the office
Theoretical part
Lighting for workrooms and offices should be designed based on the following requirements:
a) creation necessary conditions lighting on work tables located in the back of the room when performing a variety of visual work (reading typographic and typewritten texts, handwritten materials, distinguishing details of graphic materials, etc.);
b) providing visual connection with the external space;
c) protection of premises from the glare and thermal effects of insolation;
d) favorable distribution of brightness in the field of view.
Side lighting of work rooms should, as a rule, be provided by separate light openings (one window for each office). In order to reduce the required area of light openings, the height of the window sill above the floor level is recommended to be at least 0.9 m.
When the building is located in the administrative regions of the Russian Federation of light climate resource groups, the normalized value of KEO should be taken: with a depth of work rooms (offices) of 5 m or more - according to Table 3 in relation to the combined lighting system; less than 5 m - according to table 4 in relation to natural system lighting.
To ensure visual contact with the outside space, the filling of light openings should, as a rule, be done with translucent window glass.
To limit the glare of solar radiation in workrooms and offices, it is necessary to provide curtains and lightweight adjustable blinds. When designing control buildings and office buildings for the III and IV climatic regions of the Russian Federation, it is necessary to provide for the installation of light openings oriented to the horizon sector within 200°-290° with sun protection devices.
In premises, the reflectance values of surfaces must be no less than:
ceiling and top of walls.. 0.70
the bottom of the walls................... 0.50
floor........................................ 0.30.
Practical part
It is required to determine the required window area in the work rooms of the management building located in the city of Surgut (sheet 1).
Original data. Room depth d P= 5.5 m height h= 3.0 m width b P= 3.0 m, floor area A p= 16.5 m 2, height of the upper edge of the light opening above the conditional working surface h 01 = 1.9 Filling light openings with transparent glazing over metal single frames; the thickness of the external walls is 0.35 m. There is no shading by opposing buildings.
Solution
1. Considering that the depth of the room d P over 5 m, according to Table 3 we find that the normalized value of KEO is 0.5%.
2. We make a preliminary calculation of natural lighting based on the initial depth of the room d P= 5.5 m and the height of the upper edge of the light opening above the conditional working surface h 01 = 1.9 m; determine that d P /h 01 = 5,5/1,9=2,9.
3. In Figure 4 on the corresponding curve e= 0.5% find the point with the abscissa d P /h 01 = 2.9. From the ordinate of this point we determine that the required relative area of the light opening A O / A P = 16,6%.
4. Determine the area of the light opening Oh according to the formula:
0,166 A p= 0.166 · 16.5 = 2.7 m2.
Therefore, the width of the light opening b o= 2.7/1.8 = 1.5 m.
We accept a window block measuring 1.5 x 1.8 m.
5. We carry out a verification calculation of the KEO at the point A(sheet 1) according to the formula:
.
6. We superimpose graph I for calculating the KEO using the A.M. method. Danilyuk on a cross section of the room (sheet 2), combining the pole of the graph I - 0 with the point A, and the bottom line - with a conditional working surface; We count the number of rays according to graph I passing through the cross section of the light opening: n 1 = 2.
7. We note that through the point WITH on the section of the room (sheet 2) there is a concentric semicircle 26 of schedule I.
8. We superimpose graph II for calculating KEO on the floor plan (sheet 1) so that its vertical axis and horizontal 26 pass through the point WITH; Using graph II, we calculate the number of rays passing from the sky through the light opening: P 2 = 16.
9. Determine the value of the geometric KEO using the formula:
10. On a cross-section of the room on a scale of 1:50 (sheet 2), we determine that the middle of the sky section visible from the calculated point A through the light opening is at an angle ; Based on the value of this angle in Table 5, we find a coefficient that takes into account the uneven brightness of the cloudy sky of the CIE: qi =0,64.
11. Based on the dimensions of the room and the light opening, it is found that d P /h 01 = 2,9;
l T /d P = 0,82; b P /d P = 0,55.
12. Weighted average reflectance .
13. Based on the found values d P /h 01 ; l T /d P ; b P /d P according to table 6 we find that r o = 4,25.
14. For transparent glazing with a metal single frame, we find the total light transmittance.
15 According to SNiP 23-05 we find that the safety factor for windows of public buildings K h = 1,2.
16 We determine the geometric KEO at point A by substituting the values of all found coefficients into the formula:
.
Consequently, the selected dimensions of the light opening meet the requirements of the standards for combined lighting of the office.
Table 1
Groups of administrative districts
| Administrative region | |
| 1 | Moscow, Smolensk, Vladimir, Kaluga, Tula, Ryazan, Nizhny Novgorod, Sverdlovsk, Perm, Chelyabinsk, Kurgan, Novosibirsk, Kemerovo regions, Republic of Mordovia, Chuvash Republic, Udmurt Republic, Republic of Bashkortostan, Republic of Tatarstan, Krasnoyarsk Territory (north of 63° N. sh.). Republic of Sakha (Yakutia) (north of 63° N), Chukotka Autonomous Region. Okrug, Khabarovsk Territory (north of 55° N) |
| 2 | Bryansk, Kursk, Oryol, Belgorod, Voronezh, Lipetsk, Tambov, Penza, Samara, Ulyanovsk, Orenburg, Saratov, Volgograd regions, Komi Republic, Kabardino-Balkarian Republic, North Ossetia-Alania Republic, Chechen Republic, Ingushetia Republic, Khanty-Mansiysk Autonomous Okrug, Altai Republic, Krasnoyarsk Territory (south of 63° N), Republic of Sakha (Yakutia) (south of 63° N), Republic of Tyva, Republic of Buryatia, Chita Region, Khabarovsk Territory (south of 55° N. sh.), Magadan, Sakhalin regions |
| 3 | Kaliningrad, Pskov, Novgorod, Tver, Yaroslavl, Ivanovo, Leningrad, Vologda, Kostroma, Kirov regions, Republic of Karelia, Yamalo-Nenets Autonomous Okrug, Nenets Autonomous Okrug |
| 4 | Arkhangelsk, Murmansk regions |
| 5 | Republic of Kalmykia, Rostov, Astrakhan regions, Stavropol region, Krasnodar region, Republic of Dagestan, Amur Region, Primorsky Territory |
table 2
Light climate coefficient
| Light openings | Orientation of light openings along the horizon | Light climate coefficient m N | ||||
| Administrative district group number | ||||||
| 1 | 2 | 3 | 4 | 5 | ||
| In the outer walls of the building | WITH | 1 | 0,9 | 1,1 | 1,2 | 0,8 |
| NE, NW | 1 | 0,9 | 1,1 | 1,2 | 0,8 | |
| Z, V | 1 | 0,9 | 1,1 | 1,1 | 0,8 | |
| SE, SW | 1 | 0,85 | 1 | 1,1 | 0,8 | |
| YU | 1 | 0,85 | 1 | 1,1 | 0,75 | |
| In skylights | - | 1 | 0,9 | 1,2 | 1,2 | 0,75 |
| Note - C - northern; NE - northeast; NW - northwestern; B - eastern; W - western; Yu - southern; SE - southeast; SW - southwest orientation. | ||||||
Table 3
Normalized KEO values for side combined lighting in the main premises of residential and public buildings in administrative districts of various light climate resource groups
| Groups of administrative districts by light climate resources | KEO, % | |||||
| in school classes | in exhibition halls | in reading rooms | in the design rooms | |||
| 1 | 0,60 | 1,30 | 0,40 | 0,70 | ||
| 0,60 | 1,30 | 0,40 | 0,70 | |||
| 159-203 | 0,60 | 1,30 | 0,40 | 0,70 | ||
| 294-68 | 0,60 | - | 0,40 | 0,70 | ||
| 2 | 0,50 | 1,20 | 0,40 | 0,60 | ||
| 0,50 | 1,10 | 0,40 | 0,60 | |||
| 159-203 | 0,50 | 1,10 | 0,40 | 0,60 | ||
| 294-68 | 0,50 | - | 0,40 | 0,60 | ||
| 3 | 0,70 | 1,40 | 0,50 | 0,80 | ||
| 0,60 | 1,30 | 0,40 | 0,70 | |||
| 159-203 | 0,60 | 1,30 | 0,40 | 0,70 | ||
| 294-68 | 0,70 | - | 0,50 | 0,90 | ||
| 4 | 0,70 | 1,40 | 0,50 | 0,80 | ||
| 0,70 | 1,40 | 0,50 | 0,80 | |||
| 159-203 | 0,70 | 1,40 | 0,50 | 0,80 | ||
| 294-68 | 0,70 | - | 0,50 | 0,80 | ||
| 5 | 0,50 | 1,00 | 0,30 | 0,60 | ||
| 0,50 | 1,00 | 0,30 | 0,60 | |||
| 159-203 | 0,50 | 1,00 | 0,30 | 0,50 | ||
| 294-68 | 0,50 | - | 0,30 | 0,60 | ||
Table 4
Normalized values of KEO with lateral natural lighting in the main premises of residential and public buildings in various groups of administrative districts according to light climate resources
Admin groups rational areas according to light climate resources |
Orientation of light openings along the sides of the horizon, degrees. | Normalized KEO values, % | |||||
| in work rooms of management buildings, offices | in school classes | in residential premises |
vocal halls |
in reading rooms | in design rooms, drawing- design- trade bureaus |
||
| 1 | 1,00 | 1,50 | 0,50 | 0,70 | 1,20 | 1,50 | |
| 1,00 | 1,50 | 0,50 | 0,70 | 1,20 | 1,50 | ||
| 159-203 | 1,00 | 1,50 | 0,50 | 0,70 | 1,20 | 1,50 | |
| 294-68 | 1,00 | - | 0,50 | 0,70 | 1,20 | 1,50 | |
| 2 | 0,90 | 1,40 | 0,50 | 0,60 | 1,10 | 1,40 | |
| 0,90 | 1,30 | 0,40 | 0,60 | 1,10 | 1,30 | ||
| 159-203 | 0,90 | 1,30 | 0,40 | 0,60 | 1,10 | 1,30 | |
| 294-68 | 0,90 | - | 0,50 | 0,60 | 1,10 | 1,40 | |
| 3 | 1,10 | 1,70 | 0,60 | 0,80 | 1,30 | 1,70 | |
| 1,00 | 1,50 | 0,50 | 0,70 | 1,20 | 1,50 | ||
| 159-203 | 1,00 | 1,50 | 0,50 | 0,70 | 1,20 | 1,50 | |
| 294-68 | 1,10 | - | 0,60 | 0,80 | 1,30 | 1,70 | |
| 4 | 1,10 | 1,70 | 0,60 | 0,80 | 1,30 | 1,70 | |
| 1,10 | 1,70 | 0,60 | 0,80 | 1,30 | 1,70 | ||
| 159-203 | 1,10 | 1,70 | 0,60 | 0,80 | 1,30 | 1,70 | |
| 294-68 | 1,20 | - | 0,60 | 0,80 | 1,40 | 1,80 | |
| 5 | 0,80 | 1,20 | 0,40 | 0,60 | 1,00 | 1,20 | |
| 0,80 | 1,20 | 0,40 | 0,60 | 1,00 | 1,20 | ||
| 159-203 | 0,80 | 1,10 | 0,40 | 0,50 | 0,90 | 1,10 | |
| 294-68 | 0,80 | - | 0,40 | 0,60 | 0,90 | 1,20 | |
Table 5
Coefficient values qi
| Angular height of the middle ray of the sky section visible from the calculated point through the light opening in the section of the room, degrees. | Coefficient values qi |
| 2 | 0,46 |
| 6 | 0,52 |
| 10 | 0,58 |
| 14 | 0,64 |
| 18 | 0,69 |
| 22 | 0,75 |
| 26 | 0,80 |
| 30 | 0,86 |
| 34 | 0,91 |
| 38 | 0,96 |
| 42 | 1,00 |
| 46 | 1,04 |
| 50 | 1,08 |
| 54 | 1,12 |
| 58 | 1,16 |
| 62 | 1,18 |
| 66 | 1,21 |
| 70 | 1,23 |
| 74 | 1,25 |
| 78 | 1,27 |
| 82 | 1,28 |
| 86 | 1,28 |
| 90 | 1,29 |
Notes 1 For values of angular heights of the middle beam different from those given in the table, the values of the coefficient qi determined by interpolation. 2 In practical calculations, the angular height of the middle ray of the sky section, visible from the calculated point through the light opening in the section of the room, should be replaced by the angular height of the middle of the sky section, visible from the calculated point through the light opening. |
|
Table 6
Values r o for a conditional working surface
| Room depth ratio d P to the height from the level of the conventional working surface to the top of the window h 01 | Ratio of the distance of the design point from the inner surface outer wall l T to the depth of the room d P | Weighted average reflectance of floor, walls and ceiling | |||||||||||
| 0,60 | 0,50 | 0,45 | 0,35 | ||||||||||
| Room length ratio a p to its depth d P | |||||||||||||
| 0,5 | 1,0 | 2,0 | 0,5 | 1,0 | 2,0 | 0,5 | 1,0 | 2,0 | 0,5 | 1,0 | 2,0 | ||
| 1,00 | 0,10 | 1,03 | 1,03 | 1,02 | 1,02 | 1,02 | 1,02 | 1,02 | 1,02 | 1,01 | 1,01 | 1,01 | 1,01 |
| 1,00 | 0,50 | 1,66 | 1,59 | 1,46 | 1,47 | 1,42 | 1,33 | 1,37 | 1,34 | 1,26 | 1,19 | 1,17 | 1,13 |
| 1,00 | 0,90 | 2,86 | 2,67 | 2,30 | 2,33 | 2,19 | 1,93 | 2,06 | 1,95 | 1,74 | 1,53 | 1,48 | 1,37 |
| 3,00 | 0,10 | 1,10 | 1,09 | 1,07 | 1,07 | 1,06 | 1,05 | 1,06 | 1,05 | 1,04 | 1,03 | 1,03 | 1,02 |
| 3,00 | 0,20 | 1,32 | 1,29 | 1,22 | 1,23 | 1,20 | 1,16 | 1,18 | 1,16 | 1,13 | 1,09 | 1,08 | 1,06 |
| 3,00 | 0,30 | 1,72 | 1,64 | 1,50 | 1,51 | 1,46 | 1,36 | 1,41 | 1,37 | 1,29 | 1,20 | 1,18 | 1,14 |
| 3,00 | 0,40 | 2,28 | 2,15 | 1,90 | 1,91 | 1,82 | 1,64 | 1,73 | 1,66 | 1,51 | 1,37 | 1,33 | 1,26 |
| 3,00 | 0,50 | 2,97 | 2,77 | 2,38 | 2,40 | 2,26 | 1,98 | 2,12 | 2,01 | 1,79 | 1,56 | 1,51 | 1,39 |
| 3,00 | 0,60 | 3,75 | 3,47 | 2,92 | 2,96 | 2,76 | 2,37 | 2,57 | 2,41 | 2,10 | 1,78 | 1,71 | 1,55 |
| 3,00 | 0,70 | 4,61 | 4,25 | 3,52 | 3,58 | 3,32 | 2,80 | 3,06 | 2,86 | 2,44 | 2,03 | 1,93 | 1,72 |
| 3,00 | 0,80 | 5,55 | 5,09 | 4,18 | 4,25 | 3,92 | 3,27 | 3,60 | 3,34 | 2,82 | 2,30 | 2,17 | 1,91 |
| 3,00 | 0,90 | 6,57 | 6,01 | 4,90 | 4,98 | 4,58 | 3,78 | 4,18 | 3,86 | 3,23 | 2,59 | 2,43 | 2,11 |
| 5,00 | 0,10 | 1,16 | 1,15 | 1,11 | 1,12 | 1,11 | 1,08 | 1,09 | 1,08 | 1,07 | 1,05 | 1,04 | 1,03 |
| 5,00 | 0,20 | 1,53 | 1,48 | 1,37 | 1,38 | 1,34 | 1,27 | 1,30 | 1,27 | 1,21 | 1,15 | 1,14 | 1,11 |
| 5,00 | 0,30 | 2,19 | 2,07 | 1,84 | 1,85 | 1,77 | 1,60 | 1,68 | 1,61 | 1,48 | 1,34 | 1,31 | 1,24 |
| 5,00 | 0,40 | 3,13 | 2,92 | 2,49 | 2,52 | 2,37 | 2,07 | 2,22 | 2,10 | 1,85 | 1,61 | 1,55 | 1,43 |
| 5,00 | 0,50 | 4,28 | 3,95 | 3,29 | 3,34 | 3,11 | 2,64 | 2,87 | 2,68 | 2,31 | 1,94 | 1,84 | 1,66 |
| 5,00 | 0,60 | 5,58 | 5,12 | 4,20 | 4,27 | 3,94 | 3,29 | 3,61 | 3,35 | 2,83 | 2,31 | 2,18 | 1,92 |
| 5,00 | 0,70 | 7,01 | 6,41 | 5,21 | 5,29 | 4,86 | 4,01 | 4,44 | 4,09 | 3,40 | 2,72 | 2,55 | 2,20 |
| 5,00 | 0,80 | 8,58 | 7,82 | 6,31 | 6,41 | 5,87 | 4,79 | 5,33 | 4,90 | 4,03 | 3,17 | 2,95 | 2,52 |
| 5,00 | 0,90 | 10,28 | 9,35 | 7,49 | 7,63 | 6,96 | 5,64 | 6,30 | 5,77 | 4,71 | 3,65 | 3,39 | 2,86 |
If the surface finish of the room is unknown, then for the premises of residential and public buildings the weighted average reflectance coefficient should be taken equal to 0.50.
Table 7
Values of coefficients 1 and
| Type of light transmitting material | Values |
Type of binding | Values |
| Window sheet glass: | Bindings for windows and skylights of industrial buildings: | ||
| single | 0,9 | ||
| double | 0,8 | wooden: | |
| triple | 0,75 | single | 0,75 |
| Display glass 6-8 mm thick | 0,8 | paired | 0,7 |
| Reinforced sheet glass | 0,6 | double separate | 0,6 |
| Patterned sheet glass | 0,65 | steel: | |
| Sheet glass with special properties: | single opening | 0,75 | |
| single deaf | 0,9 | ||
| sun protection | 0,65 | double opening | 0,6 |
| contrasting | 0,75 | double deaf | 0,8 |
| Organic glass: | Casements for windows of residential, public and auxiliary buildings: | ||
| transparent | 0,9 | ||
| dairy | 0,6 | ||
| Hollow glass blocks: | wooden: | ||
| light-scattering | 0,5 | single | 0,8 |
| translucent | 0,55 | paired | 0,75 |
| Double-glazed windows | 0,8 | double separate | 0,65 |
| with triple glazing | 0,5 | ||
| metal: | |||
| single | 0,9 | ||
| paired | 0,85 | ||
| double separate | 0,8 | ||
| with triple glazing | 0,7 | ||
| Glass-reinforced concrete panels with hollow cores glass blocks with seam thickness: | |||
| 20 mm or less | 0,9 | ||
| more than 20 mm | 0,85 |
Table 8
Coefficient values and
| Load-bearing structures of coatings | Coefficient taking into account light loss in load-bearing structures, | Sun protection devices, products and materials | A coefficient that takes into account light loss in solar shading devices, |
| Steel trusses | 0,9 | Retractable adjustable blinds and curtains (interglazed, internal, external) | 1,0 |
| Reinforced concrete and wooden trusses and arches | 0,8 | Stationary blinds and screens with a protective angle of no more than 45° when the blinds or screens are located at an angle of 90° to the window plane: | |
| horizontal | 0,65 | ||
| vertical | 0,75 | ||
| Beams and frames are solid with section height: | Horizontal visors: | ||
| with a protective angle of no more than 30° | 0,8 | ||
| 50 cm or more | 0,8 | with a protective angle from 15° to 45° | 0,9-0,6 |
| less than 50 cm | 0,9 | (multistage) | |
| Balconies depth: | |||
| up to 1.20 m | 0,90 | ||
| 1.50 m | 0,85 | ||
| 2.00 m | 0,78 | ||
| 3.00 m | 0,62 | ||
| Loggias depth: | |||
| up to 1.20 m | 0,80 | ||
| 1.50 m | 0,70 | ||
| 2.00 m | 0,55 | ||
| 3.00 m | 0,22 |
Conclusion
During course work I studied such a parameter as natural lighting. The principle of rationing natural lighting, as well as the design of natural lighting, was considered. In this work, I calculated the natural lighting in the office. The normalized value of the natural light factor is 0.5% for the selected district. Having made a preliminary calculation, I found out the dimensions of the window unit for sufficient illumination: 1.5 * 1.8. In the verification calculation, I confirmed the correctness of the chosen dimensions of the light opening, since they meet the requirements of the standards for combined lighting of the study. The coefficient of natural light in the verification calculation is 0.53%.
GENERAL INFORMATION
Organization of rational lighting of workplaces is one of the main issues of labor safety. A lot depends on the correct lighting arrangement. industrial injuries, productivity and quality of work performed.
There are two types of lighting: natural And artificial. When calculating them, it is necessary to be guided by building codes and SNiP rules 23-05-95 “Natural and artificial lighting”.
The guidelines provide calculation methods various types natural lighting.
In accordance with the requirements of SNiP 23-05-95, all production, warehouse, household and administrative office premises must, as a rule, have natural lighting. It is not installed in rooms where photochemical exposure to natural light is contraindicated for technical and other reasons.
Natural lighting may not be provided: in sanitary premises; waiting health centers; premises for personal hygiene of women; corridors, passages and passages of industrial, auxiliary and public buildings. Natural lighting can be side, top, combined or combined.
Side natural lighting- this is the natural illumination of a room with light entering through light openings in the external walls of the building.
With one-sided side lighting it is normalized daylight factor value (KEO) at a point located at a distance of 1 m from the wall (Fig. 1.1a), i.e., farthest from the light openings at the intersection of the vertical plane of the characteristic section of the room and the conventional working surface (or floor). With side lighting, the influence of shading from opposing buildings is taken into account by the shading coefficient To ZD(Fig. 1.26).
With two-sided side lighting it is normalized minimum value KEO at a point in the middle of the room at the intersection of the vertical plane of the characteristic section of the room and the conventional working surface (or floor) (Figure 1.16).
Overhead natural lighting- this is the natural illumination of a room with light penetrating through light openings in the building’s roof and lanterns, as well as through light openings in places where there are differences in heights of adjacent buildings.
Figure 1.1 - Natural light distribution curves: A - with one-way side lighting; b - bilateral lateral; 1 - level of the conditional working surface; 2 - curve characterizing the change in illumination in the section plane of the room; RT - point of minimum illumination for lateral one-sided and two-sided illumination e min.
With top or top and side natural lighting it is normalized average value KEO at points located at the intersection of the vertical plane of the characteristic section of the room and the conventional working surface (or floor). First and last point are taken at a distance of 1 m from the surface of walls or partitions or from the axes of rows of columns (Fig. 3.1a).
It is allowed to divide the room into zones with side lighting (zones adjacent to external walls with windows) and zones with overhead lighting; rationing and calculation of natural light in each zone are carried out independently. In this case, the nature of visual work is taken into account. Conditional working surface - conditionally accepted horizontal surface, located at a height of 0.8 m from the floor.
Combined lighting is lighting in which natural and artificial light are used simultaneously during daylight hours. At the same time, natural lighting, which is insufficient for visual work conditions, is constantly supplemented with artificial lighting that meets special requirements for premises (SNiP 23-05-95 for lighting design) with insufficient natural lighting.
Figure 1.2 - Scheme for designating building dimensions for calculating natural lateral lighting:
A - size designation diagram for calculating natural side lighting: - width of the room;
L PT - distance from the outer wall to the design point (RT);
1 m - distance from the wall surface to the design point (PT);
In p- depth of the room; h 1 - height from the level of the conditional working surface to the top of the window;
h 2- height from floor level to conventional working surface (0.8 m);
L p- length of the room; N- room height; d- wall thickness;
6 - scheme for determining the coefficient To ZD: Nkz- cornice height
of the opposing building above the window sill of the building in question; Lj# - distance
between the building in question and the opposing building; M- shading border
Minimum room illumination standards are determined KEO, representing the ratio of natural light , created at a certain point of a given plane indoors by sky light (directly or after reflections), to the simultaneous value of external horizontal illumination , created by the light of a completely open sky, determined in %.
Values KEO for premises requiring various conditions illumination, taken in accordance with SNiP 23-05-95, table. 1.1.
The design of natural lighting of buildings should be based on a detailed study of technological or other labor processes carried out in the premises, as well as on the light-climatic features of the building construction site. In this case, the following characteristics must be determined:
Characteristics of visual work, determined depending on smallest size object of discrimination, category of visual work;
Location of the building on the light climate map;
Normalized value KEO taking into account the characteristics of visual work and the light-climatic features of the location of the buildings;
Required uniformity of natural light;
dimensions and the location of the equipment, its possible darkening of the working surfaces;
The desired direction of incidence of the light flux on the working surface;
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 room from the glare of direct sunlight;
Additional lighting requirements arising from the specifics technological process and architectural requirements for the interior.
Design of natural lighting is carried out in a certain sequence:
Stage 1 - determining the requirements for natural lighting of premises; definition of normative value KEO according to the category of visual work predominant in the room:
Selecting a lighting system;
Selection of types of light opening and light-transmitting material;
Selecting means to limit the glare of direct sunlight;
Taking into account the orientation of buildings and light openings on the sides of the horizon;
Stage 2 - performing a preliminary calculation of the natural lighting of the premises; i.e. calculation of glazing area Soc:
Clarification of light openings and room parameters;
Stage 3 - 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 premises, zones and areas with insufficient natural light;
Stage 4 - making the necessary adjustments to the natural lighting design and repeating the verification calculation (if necessary).
CALCULATION OF LATERAL ONE-SIDED NATURAL LIGHT
In most cases, natural lighting of industrial and administrative office premises is provided by side one-way lighting (Fig. 1.1a; Fig. 1.2a).
The method for calculating natural side lighting can be reduced to the following.
1.1.The level of visual work and the standard value of the coefficient of natural illumination are determined.
The category of visual work is determined depending on the value of the smallest size of the object of discrimination (according to the assignment) and in accordance with this, according to SNiP 23-05-95 (Table 1.1), a standard value for the coefficient of natural illumination is established , %.
Object of distinction- this is the object in question, its individual parts or a defect that needs to be distinguished during the work process.
1.2. The required glazing area is calculated Soc:
where is the normalized value KEO for buildings located in different areas;
Light characteristics of the window;
A coefficient that takes into account the darkening of windows by opposing buildings;
- floor area, m2;
Total light transmittance;
A coefficient that takes into account the reflection of light from surfaces in a room.
The values of the parameters included in formula (1.1) are determined using formulas, tables and graphs in a certain sequence.
Normalized value KEO e N for buildings located in different areas should be determined by the formula
e N =e H -m N (%),(1.2)
where is the value KEO,%, determined according to table. 1.1;
m N- light climate coefficient (Table 1.2), taken into account the group of administrative districts according to light climate resources (Table 1.3).
The value obtained from formula (1.2) KEO round to the nearest tenth.
1,5%; m N = 1,1
where is the length of the room (according to appendix 1);
The depth of the room, m, with lateral one-way lighting is equal to +d,(Fig. 1.2a);
Width of the room (according to appendix 1);
d- wall thickness (according to appendix 1);
- height from the level of the conventional working surface to the top of the window, m (Appendix 1).
Knowing the values of the relations (1.3), according to table. 1.4 find the value of the light characteristic of the window
To calculate the coefficient , taking into account the darkening of windows by a neighboring building (Fig. 1.26), it is necessary to determine the ratio
where is the distance between the building under consideration and the opposing building, m;
The height of the cornice of the opposing building above the window sill of the window in question, m.
Depending on the value according to the table. 1.5 find coefficient
The total light transmittance is determined by the expression
where is the light transmittance of the material (Table 1.6);
Coefficient taking into account light loss in window sashes of light openings (Table 1.7);
Coefficient taking into account light loss in load-bearing structures with side natural lighting = 1;
- coefficient taking into account light loss in sun protection devices (Table 1.8).
When determining the coefficient that takes into account the reflection of light from surfaces in a room, it is necessary to calculate:
a) weighted average coefficient of light reflection from walls, ceiling and floor:
Where - area of walls, ceiling, floor, m 2, determined by the formulas:
where are the width, length and height of the walls of the room, respectively (as specified in Appendix 1).
9.1 Technical and economic assessment various options natural and combined lighting of premises should be carried out for the whole year or its individual seasons. The duration of use of natural lighting should be determined by the intermediate time between the moments of turning off (morning) and turning on (evening) artificial lighting, when natural illumination becomes equal to the normalized value of illumination from the installation of artificial lighting.
In premises of residential and public buildings in which the calculated value of KEO is 80% or less of the standardized value of KEO, the norms of artificial illumination are increased by one step on the illumination scale.
9.2 Calculation of natural light in rooms should be made depending on the groups of administrative regions according to the light climate resources of the Russian Federation and the period of the year under consideration:
a) when buildings are located in the 1st, 3rd and 4th groups of administrative districts for all months of the year - according to the cloudy year;
b) when buildings are located in the 2nd and 5th groups of administrative districts for the winter half of the year (November, December, January, February, March, April) - on a cloudy sky, for the summer half of the year (May, June, July, August , September, October) - across a cloudless sky.
9.3 The average natural illumination in a room with overhead lighting from a cloudy sky at any point in the day is determined by the formula
Where e cf- average value of KEO; determined by formula (B.8) of Appendix B;
Outdoor horizontal illumination under overcast conditions; accepted according to Table B.1 of Appendix B.
Note - Outdoor illumination values in Appendix D are given for local mean solar time T M. The transition from local maternity time to local mean solar time is made according to the formula
T M = T D – N+ l - 1, (14)
Where T D- local maternity time;
N- time zone number (Figure 25);
l is the geographic longitude of the point, expressed in hourly units (15° = 1 hour).
9.4 The value of natural light at a given point A with side lighting under completely cloudy conditions, determined by the formula
where is the calculated value of KEO at the point A rooms with side lighting; determined by formula (B.1) of Appendix B;
Outdoor illumination on a horizontal surface under a cloudy sky.
Calculation of natural light at a given point M rooms away from windows in a cloudless sky should be:
a) in the absence of sunscreens in light openings and opposing buildings according to the formula
; (16)
b) when windows are shaded by opposing buildings according to the formula
c) in the presence of sunscreens in the light openings according to the formula
, (18)
where e b i- geometric KEO, determined by formula (B.9);
b b- coefficient of relative brightness of the sky area visible through the light opening; taken according to table 11;
External illumination at vertical surface, created by the diffused light of a cloudless sky; taken depending on the orientation of the surface of the building facade and the time of day according to Table B.3 of Appendix B;
Figure 25- Time zone map
b f i- average relative brightness of the facades of opposing buildings; determined according to Table B.2 of Appendix B;
Determined by formula (B.5);
r f- weighted average reflection coefficient of facades of opposing buildings; accepted according to Table B.3 of Appendix B;
External total illumination on a vertical surface created by diffuse light from the sky, direct light from the sun and light reflected from the earth's surface; accepted according to Table B.4 of Appendix B.
Calculation of the average natural illumination in a room from a cloudless sky with overhead lighting, depending on the type of light opening, is carried out:
a) for light openings in the plane of the coating filled with light-scattering materials, according to the formula
; (19)
b) for light openings in the plane of the coating filled with translucent materials, according to the formula
; (20)
c) with headlights according to the formula
; (21)
d) with rectangular lanterns according to the formula
where t O- see formula (B.1);
r 2 and k f- see formula (B.2);
e Wed- see formula (B.7);
Total outdoor illumination on a horizontal surface created by a cloudless sky and direct sunlight; accepted according to Table B.3 of Appendix B;
Outdoor illumination on a horizontal surface created by a cloudless sky; accepted according to Table B.3 of Appendix B;
b B- coefficient of relative brightness of cloudless sky areas visible through light openings; taken according to table 12;
See formula (16);
And - external illumination on two opposite sides of the vertical surface; accepted according to Table B.4 of Appendix B.
Notes
1 Direct sunlight is taken into account in illumination calculations if there are sunscreens or light-diffusing materials in the light openings; in other cases, direct sunlight is not taken into account.
2 The values of the calculated coefficients in tables 11 and 12 are given for local mean solar time.
Table 11
| Orientation of light openings | Coefficient value b b | ||||||||||||||
| Time of day, h | |||||||||||||||
| IN | 3,1 | 1,9 | 1,4 | 1,25 | 1,2 | 1,3 | 1,4 | 1,55 | 1,7 | 1,8 | 1,9 | 1,95 | 1,85 | ||
| SE | 1,05 | 1,1 | 1,45 | 2,5 | 2,6 | 1,9 | 1,5 | 1,3 | 1,25 | 1,3 | 1,35 | 1,45 | 1,6 | 1,85 | 1,9 |
| YU | 1,5 | 1,35 | 1,1 | 1,2 | 1,3 | 1,5 | 1,7 | 1,85 | 1,7 | 1,5 | 1,3 | 1,2 | 1,1 | 1,35 | 1,5 |
| SW | 1,9 | 1,85 | 1,6 | 1,45 | 1,35 | 1,3 | 1,25 | 1,3 | 1,5 | 1,9 | 2,6 | 2,5 | 1,45 | 1,1 | 1,05 |
| Z | 1,85 | 1,95 | 1,9 | 1,8 | 1,7 | 1,55 | 1,4 | 1,3 | 1,2 | 1,25 | 1,4 | 1,9 | 3,1 | ||
| NW | 1,3 | 1,5 | 1,7 | 1,75 | 1,75 | 1,7 | 1,6 | 1,5 | 1,4 | 1,3 | 1,25 | 1,25 | 1,3 | 1,9 | 2,9 |
| WITH | 1,2 | 1,2 | 1,3 | 1,45 | 1,5 | 1,6 | 1,6 | 1,65 | 1,6 | 1,6 | 1,5 | 1,45 | 1,3 | 1,2 | 1,2 |
| NE | 2,9 | 1,9 | 1,3 | 1,25 | 1,25 | 1,3 | 1,4 | 1,5 | 1,6 | 1,7 | 1,75 | 1,75 | 1,7 | 1,5 | 1,3 |
Table 12
| Type of light opening | Coefficient value b B | ||||||||||||||
| Time of day, h | |||||||||||||||
| Rectangular lantern | 1,3 | 1,42 | 1,52 | 1,54 | 1,42 | 1,23 | 1,15 | 1,14 | 1,15 | 1,23 | 1,42 | 1,54 | 1,52 | 1,42 | 1,3 |
| In the plane of the coating | 0,7 | 0,85 | 0,95 | 1,05 | 1,1 | 1,14 | 1,16 | 1,17 | 1,16 | 1,14 | 1,1 | 1,05 | 0,95 | 0,85 | 0,7 |
| Shed (oriented NW, N, NE) | 1,17 | 1,13 | 1,04 | 0,95 | 0,9 | 0,85 | 0,8 | 0,85 | 0,9 | 0,95 | 1,04 | 1,13 | 1,17 |
Examples of calculating the time of using natural light indoors
Example 1
It is required to determine how the duration of use of natural light will change in March over an average day in work room with overhead natural lighting through skylights and with a system of general fluorescent lighting, if you reduce the designed area of skylights by half and switch to combined lighting.
The workroom is located in Moscow, the accuracy of visual work performed in it corresponds to the B-1 category of standards according to Appendix I of SNiP 23-05.
The initially designed area of the lanterns provided an average KEO value in the workroom of 5%; when the area of the lamps is halved, the average value of the KEO is 2.5%. The work is carried out in two shifts from 7 to 21 hours local time.
Solution
1 In accordance with Table 1 of the list of administrative regions for light climate resources of the Russian Federation, Moscow is located in the first group and, therefore, the calculation of natural light in the room is performed for cloudy sky conditions.
2 From Table B.1 of Appendix B, write down in Table 13 the value of external horizontal illumination under overcast conditions for different hours of the day in March.
Table 13
| Time of day (local solar time) | External horizontal illumination, lux | Average natural light indoors E avg, OK | |
| at KEO = 5% | at KEO = 2.5% | ||
| - | - | - | |
| - | - | - | |
| - | - | - |
3 Consistently substituting the value into formula (13), the values of the average indoor illumination are determined for the corresponding moments in time E cp. The calculation results are recorded in table 13.
4 According to the found values E cp build a graph (Figure 26) of changes in natural light in the room during the working day at KEO = 5% and 2.5%.
5 In Appendix I SNiP 23-05 it is found that for a workroom located in Moscow, the normalized value of KEO for the B-1 category of work is 3%.
1 - change in natural light in the room at KEO equal to 5%; 2 - the same, 2.5%; A- point corresponding to the time when artificial lighting is turned off in the morning;
B- point corresponding to the time when artificial lighting is turned on in the evening
Figure 26- Graph of changes in natural light in the room during the working day
The normalized illumination is 300 lux. When the area of the lamps is halved, the average calculated value of the KEO is 0.5 of the normalized value of the KEO; in this case, in the workroom, the normalized value of illumination from artificial lighting must be increased by one step, i.e., instead of 300 lux, 400 lux should be taken.
6 On the ordinate of the graph in Figure 26, find a point corresponding to an illumination of 300 lux, through which a horizontal line is drawn until it intersects with the curve in the first and second half of the day. Points A And B intersections with the curve are projected onto the abscissa axis. Dot A the x-axis corresponds to time t a= 8 hours 20 minutes, period b - t b= 15 hours 45 minutes
The time of use of natural lighting in the workroom with an average KEO equal to 3% is determined as the difference t b - t a= 7 hours 25 minutes
7 From Figure 26 it follows that the horizontal line corresponding to illumination of 400 lux does not intersect with the curve of changes in natural illumination with an average KEO = 2.5%, this means that the time of use of natural lighting in a workroom with a halved area of lanterns is zero , i.e., during the entire working time, a constant additional artificial lighting.
Example 2
It is required to determine the natural illumination and the duration of use of natural light during the day in September under continuous cloud cover at three points A, B and C (Figure 27) of a characteristic section of a school classroom at the level of desks (0.8 m from the floor). The points are located at the following distances from the outer wall with windows: A- 1.5 m, B- 3 m and IN- 4.5 m. Calculated value of KEO at the point A e A= 4.5%, at point B e B= 2.3, at point B e B= 1.6%. Normalized illumination in classroom from the installation of artificial lighting is 300 lux. The school is located in Belgorod (50° N latitude) and operates in one shift from 8 a.m. to 2 p.m. (local solar time).
Solution
1 From Table B.1 of Appendix B, write out the values of external illumination during the day for September. Consistently substituting the values into formula (15), we obtain the values of natural illumination at given points E gA, E gb, E gV. The calculation results are recorded in table 14.
A, B, IN- Calculation points
Figure 27- Schematic cross section of a school classroom
Note - Considering that in Table B.1 of Appendix B for 50° N. w. external illumination is not given, find the required value of external illumination by linear interpolation.
Table 14
2 Based on the data in Table 14, construct a graph in Figure 28; to do this, draw a horizontal line through the point on the ordinate axis, which corresponds to an illumination of 300 lux, until it intersects with the illumination curves E gA, E gb, E gV(curves 1 , 2 , 3 ).
3 Project the points of intersection of the horizontal with the curves on the abscissa axis; time of use of natural light at a point A determined from the ratio:
t 2 - t 1 = 14 h 00 min - 8 h 20 min = 5 h 40 min.
From Figure 28 it follows that at points B And IN when it is completely cloudy in the fall, it is necessary to have constant additional artificial lighting, since throughout the day on the second and third rows of desks the natural illumination is below the normalized value.
1 - at the point A; 2 - at the point B; 3 - at the point IN
Figure 28- Graph of changes in natural light at three calculated points of the school classroom during the working day
When lighting industrial premises they use daylight, is carried out due to direct and reflected light from the sky.
From a physiological point of view, natural light is the most favorable for humans. During the day it varies within a fairly wide range depending on the state of the atmosphere (cloudiness). When light enters a room, it is repeatedly reflected from the walls and ceiling and hits the illuminated surface at the point being examined. Thus, the illumination at the point under study is the sum of the illumination.
Structurally, natural lighting is divided into:
lateral(one-, two-sided) - carried out through light openings (windows) in the external walls;
top– through light openings located in the upper part (roof) of the building;
combined– a combination of top and side lighting.
Natural lighting is characterized by the fact that the created illumination varies depending on the time of day, year, and meteorological conditions. Therefore, the relative value – daylight factor(KEO), or e, independent of the above parameters.
Daylight factor (NLC) – ratio of illumination at a given point indoors E vn to the simultaneous value of external horizontal illumination E n, created by the light of a completely open sky (not covered by buildings, structures, trees) expressed as a percentage, i.e.:
(8) Where E vn– indoor illumination at the control point, lux;
E n – simultaneously measured illumination outside the room, lux.
For measuring actual KEO needs to be carried out simultaneous measurements indoor lighting E vn at the control point and external illumination on a horizontal platform under completely open sky E n , free from objects(buildings, trees ) , covering certain parts of the sky. KEO measurements can only be carried out with continuous uniform cloudiness of ten points(totally cloudy, no gaps). Measurements are carried out by two observers using two lux meters, simultaneously (observers must be equipped with chronometers).
Checkpoints for measurements should be selected in accordance with GOST 24940–96 “Buildings and structures. Methods for measuring illumination."
The KEO values for various premises range from 0.1–12%. Normalization of natural lighting is carried out in accordance with SNiP 23–05–95 “Natural and artificial lighting”.
In small rooms with unilaterally lateral lighting is normalized (i.e. the actual illumination is measured and compared with standards) minimum KEO value at a point located at the intersection of the vertical plane of the characteristic section of the premises and the conventional working surface at a distance of 1 m from the wall, most remote from light openings.
Working surface– the surface on which work is performed and on which illumination is normalized or measured.
Conditional working surface– horizontal surface at a height of 0.8 m from the floor.
Typical section of the room- this is a cross section in the middle of the room, the plane of which is perpendicular to the plane of the glazing of the light openings (with side lighting) or the longitudinal axis of the spans of the room.
At bilateral lateral lighting is normalized minimum KEO value– in the plane in the middle premises.
IN large-sized production premises at lateral lighting, the minimum value of KEO is normalized at the point away from light openings:
at 1.5 room heights - for work of categories I–IV;
at 2 room heights – for work of categories V–VII;
to 3 heights of the room for work of the VIII category.
At upper and combined lighting is standardized average KEO value at points located at the intersection of the vertical plane of the characteristic section of the room and the conventional working surface or floor. The first and last points are taken at a distance of 1 m from the surface of walls or partitions.
(9)
Where e 1 , e 2 ,..., e n - KEO values at individual points;
n- number of light control points.
It is possible to divide the room into zones with different conditions of natural lighting; the calculation of natural lighting is carried out in each zone independently of each other.
At insufficient according to standards natural light V production premises his supplemented with artificial lighting. This kind of lighting is called combined .
In industrial premises with visual work of categories I–III, combined lighting should be installed.
In large-span assembly shops, in which work is carried out in a significant part of the room volume, different levels from the floor and on work surfaces differently oriented in space, overhead natural lighting is used.
Natural light should illuminate work areas evenly. For overhead and combined natural lighting, determine unevenness natural lighting of industrial premises, which should not exceed 3:1 for works I–VI discharges according to visual conditions, i.e.
(10)
Definite according to table 1 SNiP 23–05–95 KEO value is specified taking into account the characteristics of visual performance, lighting system, area where buildings are located in the country according to the formula
,
(11)
where N– number of the natural light supply group (Appendix D SNiP 23–05–95);
e n– coefficient of natural light (Table 1 SNiP 23–05–95);
m N– light climate coefficient, determined depending on the area where the building is located in the country and the orientation of the building relative to the cardinal points (see Table 4 of SNiP 23–05–95).