Natural side lighting. Calculation of lateral one-sided natural lighting. The choice of window systems for the building

Natural lighting is the most favorable for vision, since sunlight is necessary for normal human life. Visible rays of the solar spectrum (400-760 microns) provide the function of vision, determine the natural biorhythm of the body, positively affect emotions, the intensity of metabolic processes; ultraviolet spectrum (290-400 microns) - stimulates the processes of metabolism, hematopoiesis, tissue regeneration and has anti-rachitic (vitamin D synthesis) and bactericidal action.

All premises with a permanent stay of people should, as a rule, have natural lighting.

Natural lighting of premises is created by direct, diffused and reflected sunlight. It can be side, top, combined. Lateral lighting - through light openings in the outer walls, upper - through light openings in the coating and lanterns, and combined - in the outer walls and coatings.

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

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

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

The required uniformity of natural lighting;

Equipment location;

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

The duration of the use of natural light during the day;

The need for protection from the glare of direct sunlight.

As hygienic indicators of natural illumination of premises, the following are used:

Coefficient of natural illumination (KEO) - the ratio of natural illumination inside the premises at control measurement points (at least 5) to the illumination outside the building (%). There are two groups of methods for determining KEO - instrumental and calculation.

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

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

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

However, this coefficient does not take into account climatic conditions, architectural features of the building and other factors that affect the intensity of lighting. So, the intensity of natural lighting largely depends on the arrangement and location of windows, their orientation to the cardinal points, the shading of windows by nearby buildings, green spaces.

Incident angle - the angle formed by two lines, one of which runs from the workplace to the upper edge of the glazed part of the window opening, the other - horizontally from the workplace to the window. The angle of incidence decreases with distance from the window. It is believed that for normal illumination with natural light, the angle of incidence must be at least 27 °. The higher the window, the greater the angle of incidence.

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

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

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

The color of the walls affects the illumination of the premises: white reflects up to 80% of the sun's rays, gray and yellow - 40%, and blue and green - 10-17%.

To make better use of the light flux entering the room, walls, ceilings, and equipment should be painted in light colors. Particularly important is the light coloring of window frames, ceilings, and upper parts of walls, which provide maximum reflected light rays.

Dramatically reduces the natural illumination of the premises by cluttering up the light openings. Therefore, at enterprises it is forbidden to force windows with equipment, products, containers both inside and outside the building, as well as to replace glass with plywood, cardboard, etc.

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

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

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 can also be observed. In nature, a combination of high stratus or cirrus clouds with low spreading fog is often found. In such conditions, there is a transition of sunlight from directed from below upwards to a general more diffused light, in which the shadows are washed out. At negative temperatures, the effect is more pronounced.

At dawn, excellent shots of plants, open landscapes, reservoirs, churches oriented to the east are obtained. Often fog spreads in the lowlands, near the water surface. Valley landscapes, photographed from a high point to the east, look very impressive. 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, these surfaces and the reflections from them look just great.

Photographer: Slava Stepanov.

The quality of light in the mountains is determined by the location. If the relief hides the sunrise, it is almost impossible to get interesting lighting effects. It should also be mentioned that calm is most often observed at dawn. This helps to get perfect shots of flat water surfaces.

natural light in the morning

After sunrise, the light changes very quickly. In warm months, the sun can disperse fog or haze, in cold months it can create them (as a result of frost evaporation). Weak evaporation from reservoirs, rivers, wet roads can be spectacular. If it rained at night, then in the morning the wet streets and plants, dull under normal conditions, will shine with many bright sparks.

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 a warm bright yellow with golden notes to a warmish neutral tone. In the pictures taken in the morning, human skin looks very even. The fact is that at night our skin tightens, and in the morning the face seems refreshed - the main thing is how to wash.

Photographer: Maria Kilina.

An hour later, as the sun has risen, the lighting is ideal for photography. Professional photographers often get up well 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 get up early and get to the location well in advance. You will be able to independently trace the changes in the weather and, focusing on the position of the sun, understand what time will be the optimal natural light for photographing specific scenes. It is advisable to keep appropriate records. Also do not forget that the results of observations will be valid only for a particular time of the year.

Noon

The timing and duration of ideal light depends on the latitude of the area and the season. In the northern regions, where the sun does not set, but does not rise too high, such light is observed most of the night and all day. In temperate latitudes, suitable light persists for several hours. But do not forget that in this case the position of the star changes. In winter, it can be low all day (I will talk about this in detail).

The maximum brightness is observed for four hours in the very middle of the day. In the hot summer, there are also 4 hours ideal for photography. Two of them - in the afternoon, and two more - in the morning. Between them is a dead period. At this time, there is a very high probability of getting overexposure in the photo.

Photographer: Ovchinnikova Elena.

In equatorial and tropical regions, natural light at noon is not suitable for photography. The sun is located high overhead and creates an annoying, blinding light that makes the surrounding landscapes featureless.

Sequential shooting of people can only be done using fill light through direct supplementary lighting or reflectors. It is recommended to use light having a color temperature of approximately 5.2 thousand Kelvin.

Midday light in such regions can only be used to shoot canyons and gorges, densely covered with vegetation. At other times of the day, sunlight does not fall into such corners. The presence of direct rays helps the photographer to get bright contrast pictures.

Afternoon and evening

During daytime heating, the air absorbs moisture from the water or the ground. Therefore, in the second half of the day there are changes in the spectral composition (color) of natural light, which are not always present in the morning. Warm air absorbs more moisture. Cooling as the star moves towards sunset, it loses its ability to retain moisture. The latter condenses into tiny invisible drops that remain in the form of a suspension. When it gets colder it gets foggy. This is especially true for maritime regions.

Fog is usually very faint and visually noticeable by the presence of a slight haze that can "dim" the light. For this reason, summer afternoons can seem dreary and gloomy, even when the sun is shining brightly. In the photographs, this is expressed by “pressed down” colors and tones. In the late afternoon, the situation improves as the sun's rays begin to make their way through the mist, consisting of dust and water particles, and reveal the aerial perspective.

Photographer: Maria Kilina.

In the second half of a summer day, the air in the city can look gray. If you look at the city from an airplane, you can see a veil of bluish light haze around it. Keep in mind 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 pictures, 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 different places. The same gardens are arranged in such a way as to capture sunlight as much as possible. Trees and plants take on their final form, which depends on how the sun's rays hit them. But in general, morning light is more preferable than afternoon light.

Sunset

At sunset, specific natural lighting is created, characteristic of the low position of the luminary, when the atmosphere allows red long-wave radiation to pass through and reflects short-wave blue. During the day, some of the red rays were absorbed by the haze, while the blue ones were scattered. Now the situation is reversed. The upper part of the sky remains blue because the angle of its illumination has changed. The result is cool color combinations and smooth tone gradients.

A sunset can become both a source of light and the subject of the shooting 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 haze or light clouds. Their color gradually warms up (color temperature decreases).

Many photographers consider this state of the atmosphere the most favorable for the transmission of natural light in the evening and interesting in the context of colors. If there is a need to make adjustments, this can be done through the use of blue filters.

Assessment of natural lighting in production due to its variability depending on the time of day and atmospheric conditions is carried out in relative terms of the coefficient of natural illumination - KEO. KEO - the ratio of natural illumination at the considered point inside the room (Eb) to the simultaneous value of outdoor (En) horizontal illumination without direct sunlight.

KEO is expressed as a percentage and is determined by the formula:

The KEO value is affected by the size and configuration of the room, the size and location of the light apertures, reflecting the ability of the interior surfaces of the room and the objects that shade it. KEO does not depend on the time of day and the variability of natural light. Depending on the purpose of the premises and the location of light apertures in it, KEO is standardized from 0.1 to 10%. The norms of natural lighting of the premises are set separately for the side and top location of the light openings. With one-sided side lighting, the minimum KEO value is normalized at a distance of 1 m from the windows, and with two-sided side lighting in the middle of the room. In rooms with overhead or combined lighting, the average KEO value on the working surface is normalized (no closer than 1 m from the walls). In the amenity premises of industrial buildings, the KEO value should be at least 0.25%.

The KEO values for the combined lighting of buildings located in the III zone of the light climate range from 0.2 to 3%.

The level of natural light in the premises may decrease due to contamination of glazed surfaces, which reduces the transmittance, and contamination of walls and ceilings reduces the reflection coefficient. Therefore, the norms provide for cleaning the glass of light openings at least 2 times a year in rooms with a slight emission of dust, smoke and soot, and at least 4 times in case of significant pollution. Whitewashing and painting of ceilings and walls should be done at least once a year.

As you know, light stimuli of certain parts of the solar spectrum cause various psychological reactions. Cold tones in the blue-violet part of the spectrum have a depressing, inhibitory effect on the body, yellow-green color has a calming effect, and the orange-red part of the spectrum has an exciting, stimulating effect and enhances the feeling of warmth. This property of the spectral composition of light is used to create light comfort in the aesthetic design of workshops, painting equipment and walls.

When choosing the color for painting rooms and equipment, you should use the “Instructions for the light finishing of the surface of industrial premises and technological equipment of industrial enterprises” issued by the State Construction Committee. At enterprises where workers, due to the nature and conditions of work or due to geographical conditions (northern regions), are completely or partially deprived of natural light, it is necessary to provide ultraviolet prophylaxis with sources of UV radiation (erythema lamps) that compensate for the deficiency of natural UV radiation and have a pronounced bactericidal and psycho-emotional impact on a person. Prevention of "light" starvation is carried out by long-acting ultraviolet irradiation installations, which are part of the general artificial lighting system and irradiate workers with a low-intensity UV stream during the entire time of work. Short-term ultraviolet irradiation installations are also used - fotaria, in which UV irradiation occurs for several minutes.

Insolation of industrial buildings through skylights with a large glazing area significantly increases the natural illumination of the premises, has a blinding effect due to direct or reflected glare from the sun's rays, and to combat excessive insolation, it is necessary to use stationary or adjustable sun protection devices - visors, horizontal and vertical screens , special landscaping, transparent blinds, curtains, etc.

Natural lighting systems are ideal for almost any building and structure. Indeed, unlike artificial light, natural light does not flicker, provides full light transmission, is comfortable for the eyes and, of course, is completely free.

And in general, a pleasant, warming beam of light always fills the room with a special atmosphere. Therefore, it is not surprising that since ancient times people have been trying to provide maximum natural light in their buildings.

During its development, mankind has come up with many ways to provide its home with sunlight. But all these methods can be conditionally divided into three methods.

So:

The most commonly used is side lighting.. In this case, the light streams through the opening in the wall and falls on the person from the side. Where did the name come from.

Side lighting is quite simple to implement and provides high-quality illumination inside the house. At the same time, in wide halls, when the walls opposite from the window are located far away, sunlight does not always reach all corners of the room. To do this, increase the height of window openings, but such an exit is not always possible.

More interesting for such rooms is overhead lighting.. In this case, the light falls from the openings in the roof and streams onto the person from above.

This type of lighting is almost ideal. After all, with proper planning, you can provide illumination to any corner of the house.

But as you understand, it is possible only with one-story planning. Yes, and the heat loss of this type of natural lighting is an order of magnitude higher. After all, warm air always rises, and there are cold windows.

That is why there is natural combined lighting. It allows you to take the best of the first two types. After all, lighting is called combined, in which light falls on a person both from above and from below.

But as you understand, this type of lighting is also possible only in a one-story building or on the upper floors of multi-story buildings. But the cost of such window systems is not an unimportant limiting factor in their use.

Methods for Proper Planning of Natural Lighting

But knowing the types of natural lighting, we are not one step closer to uncovering the question of how to organize the right lighting at home? To answer it, let's take a step-by-step look at the main stages of planning.

Standards for natural lighting in buildings

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

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

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

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

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

For overhead and combined lighting, the normalized point is a plane a meter from the darkest walls. This rule also applies to industrial premises.
But all that we have given above, the instruction prescribes to be applied to residential and public buildings. With production, everything is a little more complicated. The thing is, production is different. On some I process meter blanks, while on others I deal with microcircuits.
Based on this, all types of work were divided into eight classes depending on the category of visual work. Where products less than 0.15 mm are processed, they were assigned to the first group, and where accuracy is not particularly needed, they were assigned to the eighth. And for industrial enterprises, KEO is chosen based on the category of visual work.

The choice of window systems for the building

Natural light will enter our building through the windows. Therefore, knowing the norms that we need to comply with, we can proceed to the choice of windows.

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

	Rectangular light-aeration lanterns are recommended for use in II-IV climatic zones. At the same time, if the installation is carried out in the territories south of 55 ° latitude, then the orientation of the lamp should be made to the south and north. Such lanterns should be used in buildings with an excess of sensible heat above 23 W / m 2, and with a level of visual work of the IV-VII category.
	Trapezoidal light-aeration lamps are designed for the first climatic zone. They are used for buildings in which class II-IV visual work is performed and having an excess of sensible heat above 23 W / m 2.
	Antiaircraft lamps are recommended to be installed in I-IV climatic zones. At the same time, when buildings are located south of 55 0, diffusing or heat-shielded glasses should be used as light-transmitting materials. It is used for buildings with an excess of sensible heat less than 23 W / m 2 and for all classes of visual work. It is important to note that the lights should be evenly spaced over the entire roof area.
	Anti-aircraft lamp with a light guide shaft can be used for all climatic zones. It is usually used for buildings with air conditioning and a small range of temperature differences (for example, it is quite possible to mount it yourself in residential buildings), as well as for areas where class II-VI work is performed. Found wide application in buildings with false ceilings.

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

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

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

For lateral natural lighting, an important aspect is the shading of window systems from adjacent buildings. This must be taken into account in the calculations.

For buildings in which the wall opposite the window is at a considerable distance, multi-tiered window systems are often mounted. But it should be remembered that the height of one tier should not exceed 7.2 meters.
A very important aspect when choosing window systems is their correct orientation to the cardinal points. After all, it's not a secret for anyone that south-facing windows give much more light. This should be used to the maximum in buildings under construction in northern latitudes. At the same time, for buildings under construction in southern latitudes, it is recommended to orient windows to the north and west.

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

Combination of KEO standards and illumination standards

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

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

Critical outdoor illumination is called natural illumination in an open area equal to the normalized value of artificial lighting. This value allows you to bring KEO in accordance with the requirements for artificial lighting.
For this, the formula E n \u003d 0.01eE cr is used, where E n is the normalized value of illumination, e is the selected KEO standard, and E cr is our critical outdoor illumination.

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

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

Output

Rooms without natural light are nowhere near as comfortable as buildings with direct sunlight. Therefore, if possible, natural light must be created for any buildings and structures.

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