Natural lighting - information and assessment methods

Facts about natural light and vision

As mentioned earlier, daylight is necessary in buildings

It should be sufficient in a school, although proper lighting in a small sales area or even a warehouse is equally important. In the lives of train drivers, as well as drivers of public and private transport, lighting generally plays a key role.

They need to clearly see and distinguish between signals and instrument readings located on control panels. Drivers should also have a clear view of the road ahead. In this case, the correct distribution of light sources is the key to the safety of the driver and passengers.

The human eye distinguishes objects due to the difference in brightness of the object itself and the background - this is contrast sensitivity. The smaller the differences a person notices, the higher the contrast sensitivity of his eyes. However, it has a limit, after which it decreases.

In addition, the eyes have a resolving power associated with the ability to distinguish the smallest details. Normally it is equal to one. Resolving power decreases as the eye's sensitivity to small elements increases.

Visual acuity is inversely proportional to resolving power. It just increases as a person’s ability to notice the smallest details increases. If a person’s resolving power is 2, then his visual acuity is 0.5.

The performance of vision is determined by a number of factors:

the brightness of the object that a person is looking at;
contrast between subject and background, as well as viewing time and angular dimensions.

The visual performance of the eye becomes better if the working surface is well illuminated. Also, shine should be removed from the field of view. Visual work is divided into 5 categories (see table).

Vision accuracy	Minimum size of distinguishable object	Vision work category
Highest	Up to 0.15 mm	I
Very high	0.15 - 0.3 mm	II
High	0.3 - 0.5 mm	III
Average	0.5 - 1 mm	IV
Small	1 - 5 mm	V

Effect of lighting on vision

Standards

Based on hygiene standards, the following principles are distinguished:

purpose of industrial and residential premises;
size of small parts for visual discrimination;
background contrast of rooms;
speed of detailed perception;
type of natural light;
type of artificial source.

To prevent the negative impact of reduced lighting levels, it is necessary to rationally locate production areas. Thus, the following hygiene requirements for rational lighting are highlighted:

uniform distribution;
proximity to the sun's rays;
lack of glare and shine.

Lighting is the use of sunlight and artificial lighting devices to rationally ensure hygiene and perception of the entire surrounding space. According to regulatory hygiene, it is divided into 3 varieties: natural, artificial and mixed.

For natural light

Natural lighting comes from the action of the sun's rays, as well as from the diffused sky. It is highly valued because human eyes always adapt to it. Illumination should be used evenly in different areas of enterprises.

Natural lighting is mandatory for administrative, domestic, and industrial premises. And in corridors and other utility rooms, light can enter through the glazed partitions of adjacent rooms. It can also come from both windows and ceilings, or in a combined way.

Natural light hygiene depends on:

geographic latitude of the area;
window locations;
opening designs;
time of year and day;
weather conditions.

The hygiene of lighting is significantly increased by the influence of light colors and shades that cover parts of the furniture, as well as the ceiling and walls. So, judging by the value of the natural light coefficient, white color reflects about 80%, so most commercial enterprises paint as many pieces of furniture as possible only in light colors. And cluttering windows reduces lighting in industrial premises, so it is not recommended to fill the area of window openings with various rubbish or use artificial substitutes instead of glass.

The upper part of the window should be at a distance of about 0.15-0.3 meters from the ceiling, so the light penetrates most deeply into the room. The surface of the frames should not exceed 25% of the total window area. Glass should always be straight and clean, otherwise up to 50% of natural light may be blocked.

For artificial lighting

Artificial lighting is divided into 3 types: general, local and mixed. Most often, people use general lighting that comes from overhead bulbs. Local is intended for illumination of production areas.

Depending on how the lighting is distributed over the surface, lighting devices with direct, diffuse, and reflected light are distinguished. Direct light is always directed from top to bottom. Such lamps have a blinding effect, cause eye fatigue and negatively affect mental stability.

Reflected light acts in the reverse order. It goes to the ceiling, and from there it is reflected down. This hygienic illumination is most pleasing to the eye, as it always distributes artificial light evenly.

The most common type is diffuse lighting, which always meets all hygienic standards. This type of light protects the eyes from bright light and distributes it evenly on all sides.

Dust is one of the most harmful pollutants

Hygienists have long noticed that dust, when it enters the body, harms a person in several ways. Russian doctor F.F. Erisman described this process in his scientific works. It turns out that dust damages the respiratory system, scratching it with the sharp edges of small particles (mechanical effects), causes poisoning with toxic substances (chemical effects), and transports pathogenic bacteria and viruses inside a person (bacteriological effects).

Dust always dances in the air around us. And there is no escape from it. This problem is especially acute in factory workshops and premises. Small particles of industrial dust up to 5 micrometers in size penetrate very deeply into the lungs - right up to the alveoli. This means that the harmful effects are increasing. And particles ranging in size from 5 to 10 micrometers, as a rule, remain in the upper respiratory tract.

To assess the harmful effects of dust on the human body, it is necessary to know its approximate amount in the air and its composition. The dust content in the air basin is measured by the mass of dust particles per unit volume and is expressed in milligrams per cubic meter. Sometimes another value is used - a specific number of dust particles in 1 cubic centimeter of air.

The determining factor influencing the development of dust pathology is the mass of dust accumulated in the body. Although its quantity depends on the concentration of dust particles in the air and their dispersion.

Lighting standards for the workplace

There are various indicators that indicate the optimal number of suites for different properties. The main groups are an office, a production facility, a warehouse, and a residential building. All requirements are drawn up in accordance with SNiP and are indicated in the LC for each site.

Light level in the office

For a general office where a computer device is used – 200-300 Lux.
For offices with a large area and a designer layout - 400 Lux.
For offices where work with drawings is carried out - 500 Lux.
For a conference room – 200 Lx.
For stairs and escalators – 50-100 Lux.
For the corridor and hall – 50-75 Lx.
For the archive – 75 Lk.
For the pantry – 50 Lux.

Hygienic requirements for natural lighting in the home

Indicators. The most common methods for assessing natural lighting are lighting and geometric. The first includes the determination of the coefficient of natural illumination (KEO), the second - the determination of the light coefficient, the angle of incidence of light rays, and the angle of the opening.

KEO is the ratio of the illumination of a point located inside a room to the simultaneous illumination of a horizontal surface located outside the room and illuminated by diffuse light from the entire sky.

KEO= Ep/Eo100%,

where En is the illumination (lx) of a point located indoors at a distance of 1 m from the wall opposite the window; E0 is the illumination (lx) of a point located outdoors, provided it is illuminated by diffused light from the entire sky.

The value of this coefficient is expressed as a percentage and is normalized depending on the purpose of the room and the nature of the work performed in it. For residential premises, KEO must be at least 0.5

The angle of incidence of light rays is formed by two lines emanating from one point on the table to the upper and lower edges of the window. The magnitude of this angle decreases as you move away from the window. Normal illumination with natural light will be ensured if the angle of incidence of light rays is less than 27 degrees. This indicator allows only a rough estimate of the level of natural illumination in the premises, since it does not take into account many factors that influence the amount and duration of illumination. It must be resorted to when the KEO cannot be determined (there are no graphs, nomograms and corresponding tables).

The angle of the hole allows us to judge the size of the vault of heaven directly illuminating the place under study. The larger the angle, the larger the visible area of the sky and the better the lighting.

The angle of the opening is also formed by two lines emanating from the observation point to the upper edge of the window and to the upper point of the opposing building or tree (obscuring the light of an object) located in front of the window outside the building. The magnitude of this angle characterizes the visible part of the sky, i.e., it gives an idea of the degree of darkening of the room by tall objects located in front of the windows. The hole angle must be at least 5 degrees.

Luminous coefficient is the ratio of the glazed surface of windows to the floor area in the room. It is expressed as a fraction. The numerator is the size of the glazed surface of the windows, and the denominator is the size of the floor area. The numerator is taken as one, and in this case the denominator is set to a number showing how much of the floor area is occupied by the glazed surface of the windows. The standard luminous coefficient depends on the nature of the lighting. For residential premises it should be at least 1/8-1/10.

All of the above indicators of natural light are, to one degree or another, related to the insolation of premises. Insolation is the irradiation of surfaces by direct sunlight. In accordance with the “Sanitary norms and rules for ensuring insolation of residential premises and public buildings, as well as residential areas of cities and other populated areas”, it is necessary to ensure continuous direct solar irradiation in territories and premises for at least three hours a day for buildings for the period from 22 March to September 22 in areas starting from 60° N. w. and further south, from April 22 to August 22 for areas north of 60° N. w. The insolation conditions of the territory and premises are calculated when choosing types of buildings and their orientation, when determining the relative placement of buildings, choosing sites for children's institutions and schools, playgrounds and utility areas.

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Standardization and assessment of natural lighting in premises

Standardization and hygienic assessment of natural lighting of existing and designed buildings and premises is carried out in accordance with SNiP II-4-79 using lighting engineering (instrumental) and geometric (calculation) methods.

The main lighting indicator of natural lighting of premises is the natural illumination coefficient

(KEO) - the ratio of natural illumination created at a certain point on a given plane inside a room by the light of the sky to the simultaneous value of external horizontal illumination created by the light of a completely open sky (excluding direct sunlight), expressed as a percentage:

KEO = E1/E2 100%,

where E1 – indoor illumination, lux;

E2 – outdoor illumination, lux.

This coefficient is an integral indicator that determines the level of natural light, taking into account all factors influencing the conditions for the distribution of natural light in the room. Measurement of illumination on the working surface and in the open air is carried out with a lux meter (Yu116, Yu117), the operating principle of which is based on the conversion of the energy of the light flux into electric current. The receiving part is a selenium photocell having light-absorbing filters with coefficients of 10, 100 and 1000. The photocell of the device is connected to a galvanometer, the scale of which is calibrated in lux.

▼When working with a lux meter, the following requirements must be observed (MU RB 11.11.12-2002):

The receiving plate of the photocell must be placed on the working surface in the plane of its location (horizontal, vertical, inclined);
random shadows or shadows from people and equipment should not fall on the photocell; if the workplace is shaded during work by the worker himself or by protruding parts of equipment, then the illumination should be measured under these actual conditions;
the measuring device should not be located near sources of strong magnetic fields; Installation of the meter on metal surfaces is not allowed.

The coefficient of natural illumination (according to SNB 2.04.05-98) is normalized for various rooms, taking into account their purpose, the nature and accuracy of the visual work performed. In total, 8 categories of visual accuracy are provided (depending on the smallest size of the discrimination object, mm) and four subcategories in each category (depending on the contrast of the object of observation with the background and the characteristics of the background itself - light, medium, dark). (Appendix, Table 2).

With side one-sided lighting, the minimum value of KEO is standardized at the point of the conventional working surface (at the level of the workplace) at a distance of 1 m from the wall farthest from the light opening.

▼Geometric method for assessing natural light:

1) Luminous coefficient

(SC) – the ratio of the glazed area of windows to the floor area of a given room (the numerator and denominator of the fraction are divided by the value of the numerator). The disadvantage of this indicator is that it does not take into account the configuration and placement of windows, and the depth of the room.

2) Depth coefficient

(depths) (KZ) - the ratio of the distance from the light-carrying wall to the opposite wall to the distance from the floor to the upper edge of the window. The short circuit should not exceed 2.5, which is ensured by the width of the ceiling (20-30 cm) and the depth of the room (6 m). However, neither SK nor KZ do not take into account the darkening of windows by opposing buildings, so they additionally determine the angle of incidence of light and the angle of the opening.

3) Angle of incidence

shows at what angle light rays fall on a horizontal work surface. The angle of incidence is formed by two lines emanating from the point of assessment of lighting conditions (workplace), one of which is directed towards the window along the horizontal working surface, the other towards the upper edge of the window. It must be at least 270.

4) Hole angle

gives an idea of the size of the visible part of the sky illuminating the workplace. The opening angle is formed by two lines emanating from the measuring point, one of which is directed to the upper edge of the window, the other to the upper edge of the opposing building. It must be at least 50.

The assessment of the angles of incidence and opening should be carried out in relation to the workstations furthest from the window.

21. Artificial lighting: hygienic significance, research methods

The lack of natural lighting must be compensated for by artificial lighting, which is the most important condition and means of expanding active human activity.

▼Requirements for artificial lighting:

· sufficient intensity and uniformity of the created lighting;

· should not have a blinding effect;

· should not create sharp shadows;

· must ensure correct color rendering;

· the spectrum created by artificial light sources should be close to the natural solar spectrum;

· the glow of light sources must be constant over time; they should not change the physical and chemical properties of indoor air;

· Light sources must be explosion- and fire-proof.

Artificial lighting is provided by lamps (lighting installations) of general and local lighting. The lamp consists of a source of artificial lighting (lamp) and lighting fixtures. Incandescent lamps and fluorescent lamps are currently used as sources of artificial electric lighting for premises

▼Compared to incandescent lamps, fluorescent lamps have a number of advantages:

1) create diffused light that does not produce sharp shadows;

2) characterized by low brightness;

3) do not have a blinding effect.

However, fluorescent lamps have a number of disadvantages:

1) color rendering violation;

2) creating a feeling of twilight in low light;

3) the appearance of monotonous noise during operation;

4) periodicity of the light flux (pulsation) and the appearance of a stroboscopic effect - a distortion of visual perception of the direction and speed of rotating, moving or changing objects.

Lighting fixtures are used to redistribute the light flux for the required purposes. It also protects the eyes from the glare of the light source, and the light source from mechanical damage, moisture, explosive gases, etc. In addition, the fittings play an aesthetic role.

To characterize artificial lighting, note the type of light source (incandescent lamps, fluorescent lamps, etc.), their power, lighting system (general uniform, general localized, local, combined), type of fittings and, in connection with this, the direction of the luminous flux and character light (direct, diffuse, reflected), the presence or absence of sharp shadows and shine.

Reflected gloss –

the characteristic of reflection of the light flux from the working surface in the direction of the worker’s eyes, which determines a decrease in visibility due to an excessive increase in the brightness of the working surface and a veiling effect that reduces the contrast between the object and the background. The requirements for lighting installations are reflected in the Appendix (Table 4).

The hygienic standardization of artificial lighting is based on such conditions as the purpose of the room, the nature and conditions of work or other activities of people in a given room, the smallest dimensions of the parts in question, their distance from the eye, the contrast between the object and the background, the required speed of differentiation of parts, the conditions for adaptation of the eye , driving mechanisms and other objects dangerous in terms of injury, etc. (Appendix, Table 5).

The uniformity of lighting in the room is ensured by the general lighting system. Sufficient illumination in the workplace can be achieved by using a local lighting system (desk lamps). The best lighting conditions are achieved with a combined lighting system (general + local). The use of local lighting alone without general lighting in office premises is unacceptable.

Artificial lighting assessment

Artificial illumination can be measured directly on work surfaces using a lux meter or determined approximately by calculation method.

▼According to MU RB 11.11.12-2002, measurement of artificial lighting using a lux meter from artificial lighting fixtures (installations), including when working in combined lighting mode (natural + artificial) should be carried out at workplaces in the dark, when the ratio natural light to artificial light is no more than 0.1. With combined lighting (general + local) of workplaces, first measure the total illumination from general lighting lamps, then turn on local lighting lamps and measure the illumination from general and local lighting lamps.

To roughly estimate artificial illumination during the daytime, first determine the illumination created by combined lighting (natural and artificial), and then when the artificial lighting is turned off. The difference between the obtained data will be the approximate value of illumination created by artificial lighting.

▼Calculation method "Watt"

determination of artificial illumination is based on calculating the total power of all lamps in the room and determining the specific power of the lamps (P; W/m2). This value is multiplied by the coefficient Et, which shows what illumination (in lux) a specific power of 10 W/m2 provides.

For incandescent lamps, illumination is calculated using the formula:

E = (P • Em)/(10 • K),

where E – calculated illumination, lux;

P – specific power, W/m2;

Et - illumination at a specific power of 10 W/m, - depends on the power of incandescent lamps and the nature of the luminous flux (found from Table 9 of the Appendix);

K – safety factor for residential and public buildings is 1.3.

The formula is suitable for lamps of the same power. For lamps of different power, illumination calculation is carried out separately for each group of lamps. The results are summarized.

When using fluorescent lamps, a specific power of 10 W/m2 corresponds to 150 lux of illumination (regardless of their power and the nature of the luminous flux).

▼Calculation of the required number of lamps

to create a given level of artificial illumination in a room can be done by calculation using specific power tables (Appendix, Table 6). These tables are compiled for the corresponding luminaires and the corresponding reflectance coefficients of the ceiling, floor and walls (Ppot, Ppol, Pst).

The value of the specific power depends on the height of the lamp suspension, the area of the room and the level of illumination that needs to be created in this room.

To determine the required number of lamps, the found specific power value (at the intersection of the required level of illumination and the area of the room, taking into account the height of the suspension) must be multiplied by the area of the room and divided by the power of all lamps included in the lamp. The SHOD lamp includes two fluorescent lamps with a power of 40 or 80 W.

▼Calculation of the brightness of the illuminated surface

performed according to the formula:

L = (E • K)/π,

where L – brightness – luminous intensity emanating from a unit surface area in a certain direction (candela/m2; cd/m2);

E – illumination, lux;

K is the surface reflectance coefficient (the ratio of the reflected light flux to the incident light flux);

π =3.14.

Surface reflectance values: white –0.8; light beige – 0.5; light yellow – 0.6; green – 0.46; light blue – 0.3; dark yellow – 0.2; dark green – 0.1; brown – 0.15; black – 0.1; surgical field – 0.2; freshly fallen snow – 0.9; untanned skin – 0.35.

The level of brightness of a luminous surface determines its brilliance.

The optimal brightness of working surfaces is several hundred cd/m2. The permissible brightness of light sources that are constantly in a person’s field of vision is no more than 2000 cd/m2, and the brightness of sources that rarely fall into the field of view is no more than 5000 cd/m2. Brightness exceeding 5000 cd/m2 causes a feeling of glare.

▼Calculation of the illumination uniformity coefficient

(the ratio of minimum to maximum illumination) is calculated according to the formula:

q = (E 100%)/Emax,

where q – coefficient of illumination uniformity, %;

E – illumination of the working surface under study, lux;

Emax - maximum illumination in a given room, lux.

With complete uniformity of illumination, q is equal to 100%. The smaller the q value, the less uniform the illumination of the room. The illumination of the darkest place in the room should not be more than 3 times weaker than the illumination of the lightest place.

The main lighting indicator of natural lighting of premises is the natural illumination coefficient

KEO = E1/E2 100%,

where E1 – indoor illumination, lux;

E2 – outdoor illumination, lux.

▼When working with a lux meter, the following requirements must be observed (MU RB 11.11.12-2002):

The receiving plate of the photocell must be placed on the working surface in the plane of its location (horizontal, vertical, inclined);
random shadows or shadows from people and equipment should not fall on the photocell; if the workplace is shaded during work by the worker himself or by protruding parts of equipment, then the illumination should be measured under these actual conditions;
the measuring device should not be located near sources of strong magnetic fields; Installation of the meter on metal surfaces is not allowed.

▼Geometric method for assessing natural light:

1) Luminous coefficient

2) Depth coefficient

3) Angle of incidence

4) Hole angle

The assessment of the angles of incidence and opening should be carried out in relation to the workstations furthest from the window.

21. Artificial lighting: hygienic significance, research methods

The lack of natural lighting must be compensated for by artificial lighting, which is the most important condition and means of expanding active human activity.

▼Requirements for artificial lighting:

· sufficient intensity and uniformity of the created lighting;

· should not have a blinding effect;

· should not create sharp shadows;

· must ensure correct color rendering;

· the spectrum created by artificial light sources should be close to the natural solar spectrum;

· the glow of light sources must be constant over time; they should not change the physical and chemical properties of indoor air;

· Light sources must be explosion- and fire-proof.

▼Compared to incandescent lamps, fluorescent lamps have a number of advantages:

1) create diffused light that does not produce sharp shadows;

2) characterized by low brightness;

3) do not have a blinding effect.

However, fluorescent lamps have a number of disadvantages:

1) color rendering violation;

2) creating a feeling of twilight in low light;

3) the appearance of monotonous noise during operation;

4) periodicity of the light flux (pulsation) and the appearance of a stroboscopic effect - a distortion of visual perception of the direction and speed of rotating, moving or changing objects.

Reflected gloss –

Artificial lighting assessment

Artificial illumination can be measured directly on work surfaces using a lux meter or determined approximately by calculation method.

▼Calculation method "Watt"

For incandescent lamps, illumination is calculated using the formula:

E = (P • Em)/(10 • K),

where E – calculated illumination, lux;

P – specific power, W/m2;

Et - illumination at a specific power of 10 W/m, - depends on the power of incandescent lamps and the nature of the luminous flux (found from Table 9 of the Appendix);

K – safety factor for residential and public buildings is 1.3.

The formula is suitable for lamps of the same power. For lamps of different power, illumination calculation is carried out separately for each group of lamps. The results are summarized.

When using fluorescent lamps, a specific power of 10 W/m2 corresponds to 150 lux of illumination (regardless of their power and the nature of the luminous flux).

▼Calculation of the required number of lamps

The value of the specific power depends on the height of the lamp suspension, the area of the room and the level of illumination that needs to be created in this room.

▼Calculation of the brightness of the illuminated surface

performed according to the formula:

L = (E • K)/π,

where L – brightness – luminous intensity emanating from a unit surface area in a certain direction (candela/m2; cd/m2);

E – illumination, lux;

K is the surface reflectance coefficient (the ratio of the reflected light flux to the incident light flux);

π =3.14.

The level of brightness of a luminous surface determines its brilliance.

▼Calculation of the illumination uniformity coefficient

(the ratio of minimum to maximum illumination) is calculated according to the formula:

q = (E 100%)/Emax,

where q – coefficient of illumination uniformity, %;

E – illumination of the working surface under study, lux;

Emax - maximum illumination in a given room, lux.

Regulatory requirements at a glance

The main regulatory document regulating natural lighting in residential buildings is SanPiN 2.2.1/2.1.1.1278-03

“Hygienic requirements for natural, artificial and combined lighting of residential and public buildings” (download a scanned copy) with amendments and additions in 2010 (download).

The standards indicate the values of the standard indicator of natural lighting of premises - KEO

(natural light factor) and control points at which these values must be ensured are determined.

Natural lighting in residential buildings is standardized only in living rooms and kitchens

, not counting the general house evacuation routes. In other rooms, a lack of natural light is allowed.

Natural lighting of areas of territories, both urban and garden, is not specified in the standards

.
There are insolation standards for areas of territories (download a scanned copy), but there are no standards for natural lighting of areas of territories
.

The standard value of KEO depends on the location of the light opening

(side or top).
Considering that overhead natural lighting of residential premises is exotic and less sensitive to shading by surrounding buildings, further we will consider only natural lighting of premises with lateral light openings. In this case, the KEO value should be 0.5%
. SanPiN 2.2.1/2.1.1.1278-03 provides different values for offices and children’s rooms, but in design practice they are practically not used, with the exception of the construction of private houses on an individual order. It is assumed that residents of mass-built residential buildings accept the assignment of rooms at their own discretion, allocating the brightest areas of the apartments for children's rooms and offices. In addition, the newer SanPiN 2.1.2.2645-10 “Sanitary and epidemiological requirements for living conditions in residential buildings and premises” does not provide these values.

Natural lighting in a room depends not only on the KEO value, but also on the location of the point at which it is provided

. In all residential premises, the KEO calculation (control) point is located on the floor, along the axis of the room. If the room has a non-rectangular shape, for the correct location of the calculation (control) point, the shape of the room should be reduced to a rectangle, one of the sides of which is a wall with a light opening.

The standard value of KEO, depending on the composition of the rooms in the apartment, should be provided either in the center of the room or in the depths

(at a distance of 1 m from the wall farthest from the window with a light opening). In the interior of the room, the design point should be located in the living room of a one-room apartment, in one of the rooms of two- and three-room apartments, or in two rooms of apartments with more than three rooms. In other living rooms of apartments and kitchens, the control point is located in the center of the room. Particular attention is paid to the case when living rooms have two windows in opposite or angled walls (two-way natural lighting). In this case, the KEO control point is located in the center of the room, including in one-room apartments.

How is illumination measured (natural and artificial lighting)

Difference between Illumination and Luminous Flux

Today in the lighting market there is a lot of confusion with technical parameters, such as luminous flux (measured in lumens (Lm) and illumination (measured in lux (Lx). Most, when selecting lamps, pay attention to the luminous flux (Lm - indicated on the packaging of each LED lamp ), and not on illumination requirements. Most often, the summed luminous flux of a lamp or LEDs, without light and heat losses, is taken into account.

Light flow

, can only be measured in a special laboratory; it is impossible to do this yourself with available instruments! In regulatory documents there is a concept of luminous flux, but there are no specific requirements for it.

Illumination

anyone can measure on their own, without complex equipment. What is illuminance?

Illumination is the ratio of the luminous flux to the area on which it falls. Moreover, it must fall on this plane exactly perpendicularly. It is measured in lux, lux (lx).

Why measure illumination?

Scientists have proven that bad (or, conversely, too good) light through the retina of the eye affects the working processes of our brain.

As a result, light affects a person’s psychological state: if there is not enough light, he feels depressed, decreased performance, drowsiness; if the light is too bright, it promotes excitement, connecting additional resources of the body, causing their increased wear and tear. Both are equally harmful.

If the light is chosen correctly, then due to improved illumination, productivity in the workplace can be increased by 25-30%.

Standards

Until recently, in Russia, to measure illumination, they were guided by the interstate standard for measuring illumination - GOST 24940-96. This GOST uses concepts such as: illuminance, average, minimum and maximum illuminance, cylindrical illuminance, natural illuminance factor (KEO), safety factor, relative spectral luminous efficiency of monochromatic radiation.

In 2012, Russia introduced its own national standard for measuring illumination, GOST R 54944-2012 “Buildings and structures. Methods for measuring illumination".

In this GOST, new concepts have been added to those that existed before: semi-cylindrical illumination, emergency lighting, backup lighting, evacuation lighting, security lighting, work lighting.

In 2016, the Code of Rules was adjusted - SP 52.13330.2016, which, after updating in 2011, underwent minor changes, such as:

according to paragraph 4.1, now it is the average illumination that is normalized, and not the lowest;
paragraph 7.3.1 states that it is prohibited to use LED lighting devices in educational institutions;
paragraph 7.6.9 defines new standards for placing evacuation safety signs;
and etc.

Parameters for illuminance assessment

Light waves

As one of the types of electromagnetic waves, they are distinguished by the length and frequency of oscillations, which are related to each other by the following mathematical relationship:

b = c/&

where A is the wavelength; m;s—speed of light propagation, 300,000 km/h; oscillation frequency, Hz (1 Hz is equal to one oscillation per 1 s). The power of light

measured in candelas (cd). 1 cd corresponds to V60 of the intensity of light emitted in a perpendicular direction by the surface of an absolute black body with an area of 1 cm2 at a platinum solidification temperature of 1760°C.

Illumination

measured in lux. Lux (lx) is the illumination of a surface for each square meter of which a luminous flux equal to one lumen (lm) falls:

1 lux = 1 lm/1 m2.

Lumen

- this is the luminous flux emitted within a solid angle of 1 ster by a source whose luminous intensity is equal to 1 sv; is found as the ratio of the area of illumination to the square of the distance to the light source. If a surface is illuminated by several sources that create illuminances ?, E2, etc. on it, then the total illumination of the surface E will be equal to their sum.

Ripple factor

. Changing indoor lighting conditions causes adaptation of the visual organs, which is based on physiological and photochemical processes leading to changes in visual sensitivity. Frequent and sudden changes in lighting conditions affect the physical condition of the human body.

Discrimination speed

and
the stability of clear vision
of objects also depend on the level of illumination. The speed of discrimination is especially high at an illumination level of 400-500 lux; the stability of clear vision corresponds to an illumination level of 130-150 lux.

Important factors that must be taken into account when determining the illumination of premises are the color schemes of the interiors and the difference in brightness of the observed object and the background against which the object is viewed. Thus, the luminance contrast

depends on the level of illumination: the lower the illumination, the greater the contrast should be. The brightness of the background is determined by the amount of reflected light perceived by the human eye.

Types of lighting

Illumination is provided by installing windows and lamps.

In some cases, uniform illumination of the room is required, in others, the illumination of workplaces should be standard, and the illumination of the entire room may be two to three times less. This depends on the purpose of the premises and is achieved by using certain types of lamps and their placement, which is provided for by the project. Lighting can be natural or artificial.

Daylight

Sources of natural light are:

Sun,
the moon (more precisely, the light reflected by it),
scattered light of the sky (this is not just a poetic name, a term used in protocols for measuring illumination).

Natural lighting in rooms depends

from the area where the building is located. SNIP defines the concept of light climate - this is the name of the nature of changes in illumination in the open air during the day, month, year. The light climate directly depends on the geographic latitude of the area and the altitude of the sun.
from the orientation of the building,
on the distance of the building from obscuring objects;
on the location of light openings and their sizes:
Location: For better illumination of the most remote points of the premises, it is necessary that the upper border of the light opening be raised as high as possible above the floor level, and the point furthest from the window should be at a distance not exceeding twice the height of the upper edge of the opening above the floor.
Size: In residential and office premises, the requirements for the size of light openings are different: in residential premises - 1:8 in relation to the area of the illuminated floor, in service and administrative premises - at least 1:10. The size of the light opening is equal to the area of the opening minus 15% of the area attributable to window devices.

Based on all these factors, the room has a certain level of illumination, which is characterized by the natural illumination coefficient (NLC)

, which is the ratio of indoor illumination (Lx) to instantaneous outdoor illumination (Lx), measured by KEO as a percentage (%)

The coefficient of natural light for residential and public buildings and industrial premises with side lighting depends on the accuracy of the work performed and ranges from 1.5 to 2, and for rooms with rough work KEO = 0.5. With overhead and combined lighting, in accordance with SNiP, this coefficient ranges from 2 to 7.

Artificial lighting

Sources

artificial lighting - any lighting devices (lamps, luminaires, LED strips)

When determining the performance characteristics of artificial lighting, it is necessary to pay attention to

light power,
uniformity of lighting,
lack of harsh shadows and shine.

Lighting standards are established by SNiP depending on the purpose of the premises and the work carried out there.

Detailed information can be found in the articles:

Illumination standards according to regulatory documents"

“Pulsation standards according to regulatory documents”

Service factor

(inversely proportional to the safety factor, KZ, used previously)

When planning illumination at the project stage, it is important not to forget that during operation any lighting device can reduce the illumination it creates. To compensate for this decline, an operating factor (FE) is introduced during design.

FE for artificial lighting takes into account:

pollution
non-recoverable change in the reflective and transmitting properties of optical elements
decline in luminous flux
failure of light sources
contamination of the surfaces of premises, external walls of a building or structure, roadway or street.

FE for natural lighting takes into account:

contamination and aging of translucent fillings in light openings,
reduction of the reflective properties of room surfaces. As an example, when enclosing surfaces become dusty in laboratories, illumination decreases by 10% per year, in woodworking shops by 30% over six months.

Measurement of illumination of workplaces is carried out together with measurements of noise levels, dust and pollution, vibration - in accordance with SanPin (sanitary rules and regulations).

Illumination is measured using a LUXOMETER (from Lux)

A lux meter is a mobile, portable device for measuring illumination, the operating principle of which is identical to a photometer.

Rules of use:

the device is always in a horizontal position;
it is installed at points, the location of which is calculated according to the methodology specified in State Standards. The number of control points must be at least 10;
All lux meters are certified, and the lux meter error, according to GOST, should be no more than 10%.

Lux meters can be subjective or objective.

Subjective lux meter

is based on equalizing the brightness of two illumination fields (the illumination of one field is known). It consists of a valve photocell and a measuring device. The electric current produced by a photocell when its surface is illuminated is proportional to its illumination. Therefore, a measuring device calibrated in lux immediately shows the illumination value.

Objective lux meters

are more accurate, in them the role of an analyzer is performed by a selenium photocell, and the readings are recorded by a galvanometer. When light rays hit the receiving part of the photocell, an emf is generated in the device circuit, proportional to the illumination level. The instrument scale has 50 divisions indicating three limits of illumination measurements: 0-25, 0-100, 0-500 lux. If the illumination exceeds 50 lux, then an absorber is installed on the photocell, which expands the main measurement limits by 100 times, which makes it possible to measure illumination of 0-50,000 lux.

Measurements are carried out separately for artificial and natural lighting. In this case, you need to make sure that no shadow falls on the device, and that there is no source of electromagnetic radiation nearby. This will interfere with the results. After all the necessary measurements of illumination have been made, based on the results obtained, using special formulas, the necessary parameters are calculated, and a general assessment is made. That is, the obtained parameters are compared with the standard, and a conclusion is made about whether the illumination of a given room or area is sufficient.

A separate protocol is filled out for each type of measurement in each room or section of the street. An assessment protocol is issued both for each room or territory, and for the entire facility. This is required by GOST. “Illumination measurement” must be carried out according to the rules.

Recommendations for measuring illumination for LED lamps

Measurements of illumination of LED lamps must be carried out after their 2-hour operation, when they reach operating mode (several times during the day). LEDs and power supplies generate a lot of heat. It is removed due to heat-dissipating materials (aluminum, compound, etc.) and a certain design (large radiator area, etc.). However, elevated temperatures have a serious impact on illumination.
In order not to make a mistake with the illumination parameters, it is better to immediately set the illumination drop factor when designing, which depends on the type and characteristics of the object.
Monitor the operation of LED lamps and lighting parameters throughout the warranty period, because... If the manufacturer declares a warranty period of 3 years or more, then the lamps, subject to the conditions, must remain of high quality throughout the entire period.
If the operating conditions of the lamps occur at temperatures above +45 degrees, then measurements of illumination must be done much more often than regulated by the standards.

On a note:

On some Internet resources you can find information: “In living rooms, the standard lighting for incandescent lamps is 25-30 lux, for fluorescent lamps - 75 lux.” This information is out of date and indicates minimum illumination. But, as was written earlier, in the latest edition - SP 52.13330.2016, the average illumination is now standardized, and not the lowest. And taking into account the transition to LED light sources, the average illumination for residential premises is 200 Lm.

Principles of illumination regulation

As mentioned earlier, the level of illumination of the room must meet the standards of SNiP dated May 23, 1995 “Natural and artificial lighting”. The document specifies hygienic requirements, methods and principles for assessing illumination, as well as the coefficient of natural light that various types of premises must comply with.

These sanitary standards take into account not only the purpose of the premises (public, residential, administrative and household), but also the categories of visual work. The document also talks about light openings and provides a zoning of Russia according to the light climate. The Russian Federation is divided into 5 climatic regions.

Smolensk, Ryazan, Kaluga, Moscow, Tula, Vladimir, Novosibirsk, Kurgan, Sverdlovsk, Kemerovo, Nizhny Novgorod regions, the republics of Mordovia, Chuvashia, Tatarstan, Bashkortostan, Yakutia, Udmurtia, Chukotka Autonomous Okrug, Krasnoyarsk and Khabarovsk territories.
Oryol, Kursk, Belgorod, Chita, Bryansk, Penza, Lipetsk, Samara, Voronezh, Saratov, Sakhalin, Magadan, Ulyanovsk, Volgograd, Tambov regions. Republics of Komi, Kabardino-Balkaria, Chechnya, Ingushetia, Altai, part of Yakutia, Tyva, Buryatia. Khanty-Mansi Autonomous Okrug, part of Khabarovsk Territory.
Pskov, Kaliningrad, Novgorod, Yaroslavl, Tver, Ivanovo, Kostroma, Vologda, Kirov regions. Karelia. Nenets and Yamalo-Nenets AO.K
Murmansk and Arkhangelsk regions.
Astrakhan and Amur regions; Stavropol, Krasnodar and Primorsky territories. Republics of Dagestan and Kalmykia.

Standardization of window openings depending on the light climate

For each of these regions, the necessary indicators of artificial and natural lighting are given (see table on sunlight):

Openings for light (location)	The cardinal directions where the light openings are located	Light climate (coefficient)
Administrative district number
1	2	3	4	5
External walls of the building	North	1	0,9	1,1	1,2	0,8
North-West and North-East	1	0,9	1,1	1,2	0,8
East and West	1	0,9	1,1	1,1	0,8
SE, SW	1	0,85	1	1,1	0,8
South	1	0,85	1	1,1	0,75
Anti-aircraft lights	—	1	0,9	1,2	1,2	0,75

It is very important to correctly calculate the coefficient of natural light in the room. As a unified system for calculating KEO, it is customary to use the formula: e = EB / EN. https://www.youtube.com/embed/S7XVDFHsQ9Q

E in this case means KEO, which is obtained by dividing the illumination of the room with heavenly light by the illumination of the external horizontal surface. This method of calculating natural light allows you to accurately determine how windows and lanterns should be positioned in a building under construction.

Daylight

Useful Interesting articles

15.06.2005

The only source of natural light is the sun...

It emits direct sunlight, some of which is scattered in the atmosphere and creates diffuse radiation. Thus, a distinction is made between light falling directly from the sun and light from the “sky” - sunlight scattered by the atmosphere.

Natural light varies depending on the time of day, weather conditions and time of year. The main feature of natural lighting is the variability of the intensity and spectral composition of its radiation. Changes in illumination are influenced by natural and random factors.

Regular factors influencing the variability of natural light are the height of the sun above the horizon and geographic latitude. Random factors are determined by the state of the atmosphere - clear, rain, fog. A random additional factor is the reflection of light from the ground and surrounding objects.

As the sun rises, the light intensity and color temperature increase.

It is noteworthy that due to the refraction of solar rays in the atmosphere, we see the sunrise a little earlier and the sunset a little later than is actually the case. Calculations show: when we see that the lower edge of the Sun has touched the horizon, in reality it has already set.

The rays that make up sunlight, violet, blue, cyan and green, are refracted in the Earth's atmosphere more strongly than yellow and red. Therefore, the first rays at sunrise are blue and green, just like the last ray of the setting sun.

Due to scattering in the atmosphere, the blue beam is not observed. The green beam is a rare sight. It can be seen in very clean, calm and homogeneous air, when there are no upward convection currents in the atmosphere up to the horizon. Most often, the green beam is observed on the shore of a calm sea.

Table 1.2.

Spectral characteristics of natural light
Daylight phases	Color temperature of radiation, K
Direct sunlight at sunrise and sunset	2200
Direct sunlight one hour after sunrise	3500
Direct sunlight early morning and late afternoon	4000.. .4300
Sunlight at noon in summer	5400… 5800
Diffused daylight in the shade in summer	7000
Diffused daylight in cloudy weather	7500… 8400
Light from the blue sky	9500.. .30000
Data are given for the middle band (latitude 55°)

Depending on the height of the sun above the horizon, natural lighting is divided into periods of effective, normal and zenithal lighting.

The period of effective lighting is characterized by low illumination and a high content of orange-red rays in natural light. At sunrise and sunset they are equivalent to the light of incandescent lamps (see Table 1.2). Their color temperature is 3000…3200°K.

The period of normal lighting is favorable for the eyes. At this time, the illumination changes smoothly and the spectrum of natural light changes slightly.

The period of zenith illumination is characterized by the greatest difference in illumination of horizontal and vertical surfaces. It is unpleasant to the eye due to the high contrast between the illuminated areas and the illumination in the shadows. High contrast in zenith lighting is most acutely felt in southern latitudes.

Table 1.3.

Illumination of the earth's surface at different periods of the year and hours of the day, %
Months	Time of day, hour
Months	5	7	9	11	13	15	17	19	21
June	1	3	6	89	100	89	58	24	1
May - July	1	19	54	79	91	79	51	17	0
April - August	0	10	40	64	75	67	39	8	0
March - September	0	1	24	47	58	49	23	1	0
February - October	0	0	7	26	35	26	7	0	0
January - November	0	0	2	12	19	13	2	0	0
December	0	0	1	8	13	8	0	0	0
Data are given for the middle band (latitude 55°)

In cloudless weather, in the absence of haze, fluctuations in illumination associated with the influence of atmospheric factors are small. The relative average characteristics of natural light in clear weather depending on the time of day are given in Table. 1.3.

The nature of natural light is significantly influenced by the state of the atmosphere - the density of clouds, their height and location in relation to the sun, haze, fog, rain, snow. At the same time, the illumination of objects, the contrast and spectral characteristics of light change.

For example, in the presence of cumulus clouds, the illumination of unshaded objects illuminated by the sun increases by 25%, and the illumination in the shadow increases by two and a half times. The contrast of lighting is reduced by approximately half compared to lighting in cloudless weather. When there is continuous cloudiness, a significant decrease in illumination and lighting contrast is observed.

As the sun rises, not only the intensity of the light gradually increases, but also its color temperature. Particles suspended in the air scatter less rays of the short-wave part of the spectrum - violet, blue and cyan. An increase in the proportion of blue rays leads to an expansion of the short-wave part of the spectrum and, consequently, to an increase in the color temperature of daylight.

Color temperature is a measure of the objective color impression of a given light source. By definition, color temperature characterizes light sources with a continuous spectrum of radiation that emit light from a heated body.

Winter and summer time

Rice. 1.6. Changes in light and dark times of day during the year for a latitude of 50°

A person tends to get up at dawn in order to make the most of the daylight hours. This is where the idea of summer and winter time, which is now used in many countries around the world, originates. Combining waking hours with daylight hours allows you to save energy consumption: in the spring, the hands of the clocks running according to standard time are moved forward an hour, and in the fall they are set again to standard time.

In Fig. Figure 1.6 shows the change in light and dark times of day during the year for latitude 50° (latitude of Kyiv). The border between light and dark time is considered to be the beginning or end of the so-called civil twilight, that is, the time when the Sun dropped below the horizon by 6°. In the evenings, the city streets should be lit by this time. The graph shows solar true time.

The average person gets up at 7 am and goes to bed at 11 pm local time. On the graph, the waking time of such a person is marked by two horizontal dotted lines. Since March, he gets up after dawn. By moving the clock forward, he is forced to get up earlier (solid horizontal lines). This is justified by the fact that he will get up during daylight hours and spend less electricity on lighting.

Returning to winter time in October does not lead to energy savings. As it turned out, this is done solely so that in winter people do not get up much earlier than sunrise. Therefore, the transition to winter time does not seem justified. It is rational to return to maternity time, abandon the annual change of clocks and live with a constant reference, which will differ by one hour in comparison with standard time. This rhythm of life, from a biological point of view, is most favorable for humans.

Source: Science and Technology magazine

Lighting requirements

Side lighting (windows, stained glass, strip glazing)

II. Top lighting:

— anti-aircraft lights (strip, piece), light domes;

— lanterns with double-sided glazing (rectangular, trapezoidal);

- lanterns with one-sided glazing - shades;

— hollow extended light guides – a new technique for overhead lighting.

III. Combined lighting.

STANDARDING NATURAL LIGHT

en – normalized value of KEO, depends on the natural lighting system.

1) Side one-way lighting:

It must be provided in the depths or in the center of the room (depending on the purpose)

In areas with insufficient natural light, combined lighting

, in which
natural
lighting is supplemented with
artificial lighting.
Combined lighting

It is not allowed to design in living rooms, children's and medical institutions.

2) With lateral two-way lighting, it should be provided in the center of the room

3) With overhead and combined lighting, the average value

KEO – esr.

The normalized value of KEO is also determined by the nature and accuracy of visual work, that is, the purpose of the room, and takes into account the regional characteristics of the light climate.

en = en'·m

en´ – normative value of KEO, determined by the nature and accuracy of visual work.

Visual work

characterized by the object of discrimination, its size (as well as the contrast between the object and the background).
The object of discrimination
is a separate part of the object in question (a thread of fabric, a line, a scratch, etc.)

en´ for industrial premises

accepted depending on the category of visual work,
for public
- depending on the purpose of the room.

m – light climate coefficient, depends on:

• construction area;

• type of light opening;

• orientation of the light opening.

It is allowed to reduce the calculated value of KEO from the standardized value by no more than 10%.

CALCULATION OF NATURAL LIGHT

Date added: 2018-03-01; ;

COLOR DESIGN OF EQUIPMENT AND PRODUCTION PREMISES

In the production environment, color is used as a means of information and orientation, as a factor of psychological comfort and as a compositional tool. Color affects a person’s performance, fatigue, orientation, and reaction. Cool colors (blue, green, yellow) have a calming effect on a person, warm colors (red, orange) have a stimulating effect. Dark colors have a depressing effect on the psyche.

When choosing colors and interior color design, you must follow the guidelines for rational color finishing of surfaces of industrial premises and technological equipment GOST 26568-85* and GOST 12.4.026-76* SSBT.

The color scheme of the interior is characterized by color gamut, color contrast, amount of color and reflection coefficients. Color spectrum

- this is a set of colors adopted for the color scheme of the interior.
It can be warm, cold and neutral. For foundries, forges, and heat treatment shops, a cool color scheme is appropriate. Color contrast
is a measure of the difference between colors in terms of their brightness and hue. Color contrast can be large, medium or small.

Quantity of color -

This is the degree of color sensation, depending on the color tone, color saturation of the object and background, on the ratio of their brightness and angular dimensions.

When choosing a color scheme for interiors, you need to take into account the category of work, its accuracy, and sanitary and hygienic conditions. A significant role in the interior belongs to the choice of reflection coefficients (P) of surfaces.

The ceilings of the premises are painted white or close to white. Trusses and floors are painted in light colors. The lower part of the walls is painted in calm colors (light green, light blue). Metal-cutting machines are painted in light green, foundry equipment in beige, thermal equipment in silver, transport mechanisms in green.

According to GOST SSBT 12.4.026-76 “Signal colours”, red is used to warn of obvious danger, prohibition, yellow warns of danger, draws attention, green means regulation, safety, blue means information. Trolleys, electric cars, lifting mechanisms are painted yellow with yellow stripes on a black background, fire-fighting equipment is painted red

Pipelines and cylinders are painted in different colors: air ducts are blue, water pipes for process water are black, oil pipes are brown, oxygen cylinders are blue, carbon dioxide cylinders are black. The same GOST introduced safety signs: prohibitory signs - a red circle with a white stripe; warning signs - a yellow triangle with a danger printed on it; prescriptive - a green circle, inside of which there is a white square with prescriptive information; index marks - a blue rectangle with a square in the middle.

LITERATURE:

1. Alekseev S.V., Usenko V.R. Occupational hygiene. M: Medicine, - 1998.

2. Life safety: Textbook. Part 2 /E.A. Rezchikov, V.B. Nosov, E.P. Pyshkina, E.G. Shcherbak, N.S. Chvertkin /Edited by E.A. Rezchikova. M.: MGIU, - 1998.

3. Dolin P.A. Safety Handbook. M., Energoizdat, - 1982.

4. Ivanov B.S. Man and habitat: Textbook, M.: MGIU, - 1999.

Occupational safety in mechanical engineering: Textbook /Edited by E.Ya. Yudin and S.V. Belova, M. - 1983.

Hygienic requirements for natural lighting

From a hygienic point of view, the most appropriate orientation is to the south and southeast.

In mid-latitudes, the long axis of the building should be directed from northeast to southwest. In this case, residential premises are located to the south-east, and auxiliary premises - to the north-west.

It is not recommended to orient living quarters to the west, since with such an orientation significant radiation is observed in the summer and insignificant in the winter.

In the northern and southern latitudes of the USSR, it is recommended that the axes of buildings be located from west to east (equatorial) with the windows of living rooms oriented to the south and auxiliary rooms to the north; b) size and location of windows. The upper edge of the window should be located closer to the ceiling, which allows light to penetrate deeper into the room. The width of the partitions should not exceed one and a half width of the window openings

The size and number of light openings and the nature of the bindings are important for illumination. The best shapes are rectangular windows;

c) the depth of the room (in rooms with side one-way lighting - this is the distance from the wall with windows to the opposite wall). The depth of the room should not exceed more than 2 times the distance from the top edge of the window to the floor (no more than 6.5 m); d) gap between buildings. This gap must be no less than double the height of the opposite tall building; e) quality of glass and degree of purity. Ordinary glass absorbs some of the light, especially the ultraviolet portion of it. Dirty glass reduces light transmission by 25-50%. Curtains on windows can absorb up to 40% of light; f) the nature of the color of the walls and ceiling. Light colors, reflecting light, increase illumination.

Various indicators are used to characterize natural light. One of them is the coefficient of natural illumination (KEO), which means the ratio of the illumination of a point located indoors to the illumination of any point located on the same plane, located outside the room and illuminated by diffused light from the sky. Its value is expressed as a percentage and is standardized depending on the purpose of the room and the nature of the work performed. For residential premises it must be at least 0.5%.

Luminous coefficient (LC) is the ratio of the glazed surface of windows to the floor area in the room. It is expressed as a simple fraction, where the numerator is one, the denominator is a number showing how much of the floor area is occupied by the glazed surface of the windows.

The standard luminous coefficient depends on the nature of the room. For residential premises, the luminous coefficient should be at least 1/8-1/10.

Considering the bactericidal and healing effect of sunlight, it is advisable to orient hospital rooms to the south. The light coefficient in the wards should be in the range of 1:6-1:7, the natural light coefficient should be 1%. Artificial lighting in the rooms with incandescent lamps is 30 lux, with fluorescent lamps - 75 lux. It is advisable that each bed have local lighting. Night lighting must be provided in the wards.

General information

The external and internal space of premises and buildings, illuminated with the help of light emanating from the celestial body and the firmament, is natural lighting. It is created as a result of direct and diffuse sunlight, including the reflective effect from surrounding objects. The flow enters buildings through specially designed and constructed openings called light openings. In buildings where people work and live, natural lighting is a must. It should ensure a person’s comfortable stay at home and at work, and facilitate the performance of both simple and complex work. To do this, you need to know the following object indicators:

the climate zone in which it is located;
location of windows taking into account cardinal directions and their sizes;
weather;
shading by nearby objects;
season.

The intensity of lighting in the interior depends on the luminous coefficient (LC). It is a formula that takes into account the area of the light surface relative to the floor area of the room. The coefficient can have different values and ranges from 1/4 to 1/10. But the illumination at any workplace cannot be assessed only with the help of the IC. It does not take into account many factors (light losses, location of the workplace, laws of light distribution, etc.).

Natural lighting of buildings from the outside is not always enough and then additional illumination of the object is performed.

Methods for assessing natural light

To assess the illumination in a specific room and at a specific workplace, the natural illumination coefficient (LFC) is used. It is the ratio of the illumination created by a celestial body inside a room at a specific point to that measured using special instruments outside the building. Thanks to this coefficient, requirements for jobs are formed. They are called hygienic. Indicators for normalizing natural light are set out in SanPiN (Sanitary Rules and Norms) 2.2.1/2.1.1.1278-03 and according to this document, KEO should be:

in premises intended for living – 0.5 and above;
in workshops and other premises where hired workers work – 1.0 and above;
in educational and children's institutions - 3.5 and above.

All work performed on the premises, depending on the accuracy of execution, is divided into categories in accordance with the standards. There are only 8 of them. Even at the stage of creating a detailed design of any building, this helps to determine the size of window and other sources of natural light, as well as to determine the sources of artificial light. Most objects cannot be designed without natural light. And it's important to do it right.

The duration of action and intensity of luminescence by the sun's rays determines the insolation regime. The standards are specified in SanPiN 2.2.1/2.1.1.1076-01. The main criteria were 3 factors - insolation time, orientation taking into account cardinal directions and the percentage of illuminated floor area. Natural light indicators are shown in the following table:

Insolation mode	Insolation time per hour.	Cardinal directions	Insolated floor area in %	Thermal radiation in kcal/m3
Minimum	less than 3	northeast, northwest	30	500
Moderate	3 ÷ 5	South East	40 ÷ 50	500 ÷ 550
Maximum	more than 5	southeast, southwest	80	550

Insolation modes are taken into account when designing windows in building premises. For example, in northern latitudes, when windows are located on the south side, the highest level of illumination is provided compared to their location in the northern part, and in southern and middle latitudes it is better to place them in the east, southeast and south.

Natural light is greatly influenced by the reflective factor. It is well known that dark surfaces absorb more light radiation than light ones. Therefore, the coloring of walls, floors, ceilings, installed furniture and other objects installed in the premises of the facility play a role in assessing the level of lighting. Great attention is paid to the cleanliness of glass surfaces and the room itself, as well as the presence of curtains. All this must be taken into account. Two research methods are used:

lighting engineering;
geometric or also called graphic.

Using the first method, the KEO is determined, and the second is needed to determine the SC, depth coefficient (DC), opening and incidence angles. Special techniques allow you to perform calculations quickly.

To protect people from direct sunlight, you must follow the requirements of SNiPs 31-01 and 2.08.02.

Instruments for determining illumination

Illuminance is measured using lux meters, including types of devices with a remote sensor. They differ in design and convert the energy of the light stream into electric current. Based on the readings of the galvanometer, the level of illumination in lux (lux) is determined. The presence of a set of light filters allows you to measure illumination from 0 to 50,000 lux.

In rooms where people stay or live, natural lighting must be properly provided, and since it is part of the combined lighting, this will help install the necessary artificial sources that emit light energy, as well as save electrical energy consumption.

What documents regulate lighting?

Regulatory documentation that regulates local lighting and other issues:

building codes and regulations (SNiP 23-05-95);
epidemiological documents that impose sanitary requirements (SanPiN 2.2.4.3359-16);
GOST R 55710-2013.

Individual organizations may also wish to follow the guidance of industry documents, which will define the relevant provisions and regulatory values that will need to be met.

The requirements of the documents listed above apply to both completed premises (industrial purposes, etc.) and to premises that are under construction.

Hygienic requirements for natural and artificial lighting

In residential buildings located in the central, historical zone of the city, the location of the design point is taken in the center of the room, regardless of the number of rooms in the apartment.

The compliance of natural lighting in residential buildings with the requirements of the standards is determined by calculations when designing a building built into an existing building.

In this case, the calculation of natural lighting is carried out both for apartments of designed residential buildings, and for apartments of buildings falling within the shading zone of new construction.
The results of natural lighting calculations, however, depend on how competently and correctly they are performed. The reason for a possible violation of natural lighting standards may be the underestimation of this factor by the project authors at the stage of making fundamental design decisions. If the construction of the designed building is completely completed, it is customary to measure the KEO.
Calculation of KEO can also be carried out in cases where the conditions necessary for taking measurements are impossible or difficult to fulfill (light interior decoration, lack of furniture, lack of shading by green spaces, etc.).

A violation of the legally established norms for natural lighting in residential premises, established by calculation or measurements, is grounds for going to court.

LLC "INSOLYATION" - calculations of natural light and insolation, consultations on regulatory issues.

Write to: [email protected]

Call:
+7 (495) 643 34 40
to the beginning

Assessing natural light.

Methods for assessing natural light

The standardization and hygienic assessment of natural lighting is summarized from the analysis of two methods: lighting, that is, instrumental, and geometric, that is, calculated.

Lighting method

The main indicator of the lighting method is the coefficient of natural light. It is determined by the formula:

KEO=E1E2×100%{\displaystyle KEO={\frac {E1}{E2}}\times 100\%},

where E1

- indoor lighting LM,
E2
- outdoor lighting LM.

Depending on the type of premises, the type of activity that is carried out there, the KEO standards are met, which are set out in SanPiN 2.2.1/2.1.1.1278-03 “Hygienic requirements for natural, artificial and combined lighting of residential and public buildings” (approved by the Main State sanitary doctor of the Russian Federation April 6, 2003)

Hole angle

Formed by two lines emanating from the measurement point. The first is carried out to the upper edge of the window, the second - to the upper edge of the opposing building. The norm is at least 5˚.

Depth coefficient (DC)

Laying depth coefficient (CD) is the ratio of the distance from the light-carrying surface to the opposite side to the height from the floor to the upper edge of the window. In accordance with the standards, it should not exceed 2.5.

▼Geometric method for assessing natural light:

1) Luminous coefficient

2) Depth coefficient

3) Angle of incidence

4) Hole angle

The assessment of the angles of incidence and opening should be carried out in relation to the workstations furthest from the window. (Appendix, Fig. 1).

ARTIFICIAL LIGHTING

The lack of natural lighting must be compensated for by artificial lighting, which is the most important condition and means of expanding active human activity.

▼Requirements for artificial lighting:

· sufficient intensity and uniformity of the created lighting;

· should not have a blinding effect;

· should not create sharp shadows;

· must ensure correct color rendering;

· the spectrum created by artificial light sources should be close to the natural solar spectrum;

· the glow of light sources must be constant over time; they should not change the physical and chemical properties of indoor air;

· light sources must be explosion-proof and fireproof.

▼Compared to incandescent lamps, fluorescent lamps have a number of advantages:

1) create diffused light that does not produce sharp shadows;

2) characterized by low brightness;

3) do not have a blinding effect.

However, fluorescent lamps have a number of disadvantages:

1) color rendering violation;

2) creating a feeling of twilight in low light;

3) the appearance of monotonous noise during operation;

4) periodicity of the light flux (pulsation) and the appearance of a stroboscopic effect - a distortion of visual perception of the direction and speed of rotating, moving or changing objects.

Reflected gloss –

Artificial lighting assessment

Artificial illumination can be measured directly on work surfaces using a lux meter or determined approximately by calculation method.

▼
“Watt”
calculation method for determining artificial illumination is based on calculating the total power of all lamps in the room and determining the specific power of the lamps (P; W/m2). This value is multiplied by the coefficient Et, which shows what illumination (in lux) a specific power of 10 W/m2 provides.

For incandescent lamps, illumination is calculated using the formula:

E = (P • Em)/(10 • K),

where E – calculated illumination, lux;

P – specific power, W/m2;

Et - illumination at a specific power of 10 W/m, - depends on the power of incandescent lamps and the nature of the luminous flux (found from Table 9 of the Appendix);

K – safety factor for residential and public buildings is 1.3.

The formula is suitable for lamps of the same power. For lamps of different power, illumination calculation is carried out separately for each group of lamps. The results are summarized.

When using fluorescent lamps, a specific power of 10 W/m2 corresponds to 150 lux of illumination (regardless of their power and the nature of the luminous flux).

▼Calculation of the required number of lamps

The value of the specific power depends on the height of the lamp suspension, the area of the room and the level of illumination that needs to be created in this room.

▼Calculation of the brightness of the illuminated surface

performed according to the formula:

L = (E • K)/π,

where L – brightness – luminous intensity emanating from a unit surface area in a certain direction (candela/m2; cd/m2);

E – illumination, lux;

K is the surface reflectance coefficient (the ratio of the reflected light flux to the incident light flux);

π =3.14.

The level of brightness of a luminous surface determines its brilliance.

▼Calculation of the illumination uniformity coefficient

(the ratio of minimum to maximum illumination) is calculated according to the formula:

q = (E 100%)/Emax,

where q – coefficient of illumination uniformity, %;

E – illumination of the working surface under study, lux;

Emax - maximum illumination in a given room, lux.

INDUSTRIAL LIGHTING SYSTEMS AND REQUIREMENTS FOR THEM

Natural, artificial and combined lighting is provided in production premises. Premises with permanent staff must have natural light. When working in the dark, artificial lighting is used in industrial premises. In cases where work is performed with the highest precision, combined lighting is used. In turn, natural lighting can be side, top or combined, depending on the location of light openings (lanterns). Artificial lighting can be general (with uniform illumination of the room), localized (with the location of light sources taking into account the placement of workplaces), combined (a combination of general and local lighting). In addition, emergency lighting is provided (turned on when the working lighting suddenly turns off). Emergency lighting must be at least 2 lux inside the building.

In accordance with the “Building Norms and Rules” SNiP 23-05-95, lighting must ensure: sanitary standards of illumination in workplaces, uniform brightness in the field of view, absence of sharp shadows and glare, constancy of illumination over time and correct direction of the light flux. Lighting in workplaces and production areas must be monitored at least once a year. An objective lux meter (Yu-16, Yu-116, Yu-117) is used to measure illumination. The operating principle of a lux meter is based on measuring, using a milliammeter, the current from a photocell onto which the luminous flux falls. The deviation of the milliammeter needle is proportional to the illumination of the photocell. The milliammeter is calibrated in lux.

The actual illumination in the production area must be greater than or equal to the standardized illumination. If lighting requirements are not met, visual fatigue develops, overall performance and labor productivity decrease, the number of defects and the risk of industrial injuries increases. Low light contributes to the development of myopia. Changes in illumination cause frequent readaptation, leading to the development of visual fatigue.

Glare causes glare, eyestrain and can lead to accidents.

Natural lighting systems and standards

As for choosing a system, you need to proceed from the situation. Most often, standard windows are used, since it is the simplest and does not require complex calculations. To find out the optimal indicator for a particular room, use KEO - natural light coefficient. The following must be taken into account:

To calculate the coefficient, you need to divide the illumination inside the room by the external indicator and multiply by 100. The resulting result will be a guideline in percentage.
There is no point in calculating KEO on your own, since the work has already been carried out by specialists from research institutes. SNiP 05/23/95 has a table that contains the optimal values for all regions. You need to choose your own to clarify the indicator you need to focus on.
The coefficient depends on the region; the further south it is, the brighter the luminous flux and the lower the ratio between indoors and outdoors can be. Russia is divided into 5 zones, in which indicators vary from 0.2 to 0.5.
The classification also distinguishes several groups of premises depending on what work will be performed. The more clearly you need to see everything, the higher the required indicators will be. But for living rooms there is not much difference, so you can be guided by the general values that are in the table below.

Table: Natural light factors for residential premises and standards when using artificial light

Residential building premises	KEO with side lighting in%	Recommended illumination of working surfaces under artificial lighting, LC
Living rooms, bedrooms	0,5	150
Kitchens	0,5	150
Children's	0,5	200
Cabinets	1	300
Corridors	—	50
Bathrooms, bathrooms	—	50

By the way! If there are large buildings or trees nearby that block sunlight, then you need to take this point into account and increase the coefficients based on the situation.

Methods for assessing artificial light

Artificial lighting measurements are made only if the ratio of natural to artificial illumination is less than 0.1.

Calculation of the brightness of the illuminated surface

L=E×Kπ{\displaystyle L={\frac {E\times K}{\pi }}} cd/m²,
where E

— illumination, lm;
K
is the surface reflectance.

The maximum permissible brightness of a light source that is constantly in the human field of vision is 2000 cd/m², rarely falling into the field of view is 5000 cd/m²

Calculation of the lighting uniformity coefficient

q=EEmax×100%{\displaystyle q={\frac {E}{E_{max}}}\times 100\%},
where E

— illumination at the point under study, lm;
E max
- maximum illumination in the room.

Under conditions of uniform illumination q

=100%.
Normally, normally E max
should be

no more than 3 times
E. source not specified 1249 days
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