For the right organization of lighting at home there is not enough choice of places where the lamps will be located. You need to choose the right type of lamps and the power of the lamps for them. For this, the illumination is calculated.

There are norms for illumination of typical rooms or illuminated objects in them. In the reading room of the library, the operating room, the school office of light is needed more than in the corridor, the front or bathroom. For a quantitative estimate, the calculations use a physical value - illumination measured in suites.

Light measurement unit - 1 (LC, LX). The second physical value used in the calculation of the illumination is the light stream measured in (LM, LM). They are connected with each other as follows: if the surface, with an area of \u200b\u200b1 m 2, the luminous flow of 1 lm falls, then its illumination will be equal to 1 LC.

The main goal of the calculation is to create a comfortable level of illumination level on the working surface. With insufficient or excess illumination, the eyes will be tense when working, more to get tired and over the years the vision will deteriorate.

How to make the calculation of the required level of illumination?

Approximately estimated power of light sources can be calculated by the formula:

P \u003d PS / Nwhere

P. (W / m 2) - specific lighting power, depending on the types of rooms and lamps. The most frequently used values \u200b\u200bp are shown in the table.

Specific lighting

Type of room	Incandescent lamp	Halogen lamp	Daylight lamp
Children's room	30-90	70-80	18-22
Living room	10-35	25-30	7-9
Bedroom	10-20	14-17	4-5
Corridor	10-15	11-13	3-4
Kitchen	12-40	30-35	8-10
Bathroom	10-30	23-27	6-8
Pantry, garage	10-15	11-13	3-4

S. (m 2) - the area of \u200b\u200bthe room;

N. - Number of lamps.

It can be seen from the formula that a larger number of lamps create greater illumination on the same area with a lower power of the lamps in them. Each light source has its own light stream. With the same electrical power, the light flow in incandescent lamps is less than in luminescent, energy-saving, LED, as they work on different physical principles. This explains the economy of electricity: the level of illumination created by the incandescent lamp of 100 W is obtained by using a luminescent lamp 18 W.

This is a simplified calculation option that does not take into account several important factors:

— distances from the lamp to the illuminated surface. The illumination decreases with a quadratic dependence on the distance to the lamp.

— configuration of lamps. Some lamps have reflectors that guide part of the light flux down. In the absence of reflectors, its function performs the ceiling. The more reflective ability, the greater part of the light flux will be redirected.

- availability natural lighting. The more window openings, the less need artificial light.

— colors and material walls outdoor coatingsaffecting the sensation of a light man.

For simplified calculations, you can take advantage of the dependence of the illumination from the area of \u200b\u200bthe room shown in the table.

The dependence of the illumination from the area of \u200b\u200bthe room

Square of the room	Very bright light	Bright light	Soft light
sq.m.	500 LK	300 lk	150 LK
less than 6.	150w.	100w.	90w
6-8	200w.	140w.	80w.
8-10	250w.	175w	100w.
10-12	300W.	210w.	120w.
12-16	400w	280w.	160w.
16-20	500W.	350W.	200w.
20-25	600W.	420w	240w.
25-35	700W.	490w.	280w.

Here you already selected the optimal power of the power of the incandescent lamps installed in the center of the room. The required power should be reduced 5-7 times when using fluorescent lamps and 10 times for LED. More accurate values \u200b\u200bcan be determined by the packaging of the lamp on which the manufacturer indicates which power of the incandescent lamp corresponds to the luminous device.

How to measure the level of illumination?

To measure the actual light level, a special device is used. It consists of a photo sensor with a set of light filters and a measuring device. The principle of operation of the luxmeter consists in measuring the resistance of the photo sensor varying with different levels of illumination. Light filters are designed to change the measurement limits of the instrument.

The procedure for measuring illumination by a luxmeter:

1. Select the measurement limits of the photo sensor.

2. Place the photo sensor on the surface on which the illumination is required.

3. Turn on the device.

4. Removing the testimony

5. Turn off the device

The use of a luxmeter allows you to know whether the actual level of illumination corresponds to the requirements specified, for example, in. And when inconsistency - to develop measures to bring light to the required limits.

I will try to very briefly and simply set out the method of manual calculation of lighting in the rooms to which I was taught on the course "Calculation of lighting" School of LEDs LIDS.

What should be illumination
When planning lighting, first of all, it is necessary to determine the appropriate standards of target lighting and calculate the overall light stream, which should give lamps indoors.
With standards to determine simply or we are looking for your type of room in Sanpine tables 2.21 / 2.1.1 / 1278-03 "Hygienic requirements for natural, artificial and combined lighting of residential and public buildings" and SP 52.13330.2011 "Natural and artificial lighting", or We agree with the basic requirement for the illumination of residential premises - 150lk or office premises with computers - 400lk.

Rough estimate of the required light flux
By default, the illumination calculation is made in the Dialux program. But the result at least approximately need to know in advance to verify the data with the evaluation "on the eye".
As written even in Wikipedia, the average illumination of the surface is the ratio of the luminous flux falling on it. But in real premises, part of the light flux of the lamp of the work planes does not reach, disappearing on the walls. The illumination in the room is the ratio of the total light flow of the lamps to the room area with the correction coefficient "η".

The share of light "η", which comes to working surfaces, can be appreciated by eye. In the most general approximation for some very middle room with some lamps, approximately half of the light comes to working surfaces, which means that a very rough estimate can use a coefficient η \u003d 0.5.
For example, in a room with an area of \u200b\u200b20m 2, the lamp with a light flux 700lm (equivalent of incandescent lamps 60W) will create the illumination E \u003d 0.5 × 700lm / 20m 2 \u003d 18lk. And this means that in order to achieve a standard in 150lk, it is necessary f \u003d 700lm × (150lc / 18lk) \u003d 5800lm, or equivalent of 8 incandescent bulbs to 60W!
(Polkilovatta incandescent lamps on a small room! It is clear why the lighting standards for residential premises are much lower than for institutions, and why the institutions have long been not covered by incandescent lamps.)

More accurate method of manual calculation
But since the premises are with different walls, of different shapes, with high or low ceilingsA correction factor is not necessarily 0.5 and for each case its own: in practice, from 0.1 to 0.9. In the fact that the difference between η \u003d 0.3 and η \u003d 0.6 already means running out the results twice.
The exact value of η should be taken from the table of the utilization coefficient of the light stream developed in the USSR. In full, with explanations of the table, we bring in a separate document. Here we use the excerpt from the tables for the most popular case. For standard light room with reflection coefficients of the ceiling of walls and floor in 70%, 50%, 30%. And for the luminaires mounted on the ceiling, which will shine under themselves and a little sideline (that is, they have a standard, so-called, "cosine" curve of the forces of light).

Table. 1 The coefficients of using the light flux for ceiling lamps with a cosine chart in the room with the reflection coefficients, walls and floor - 70%, 50% and 30%, respectively.

In the left column of the table, the index index is indicated, which is considered by the formula:

where S is the area of \u200b\u200bthe room in m 2, a and b - the length and width of the room, H is the distance between the lamp and the horizontal surface on which we calculate the illumination.
If we are interested in the average illumination of the working surfaces (tables) in the room 20m 2 with walls 4m and 5m, and the height of the suspension of the lamp over the tables 2m, the indoor index will be equal to i \u003d 20m 2 / ((4m + 5m) × 2.0 m) \u003d 1.1. Making sure that the room and lamps correspond to the signature to the table, we obtain the utilization factor of the light flux - 46%. The multiplier η \u003d 0.46 is very close to the presidency η \u003d 0.5. The average illumination of working surfaces with a total light flow 700lm will be 16lk, and to achieve the target 150lk, it will take f \u003d 700lm × (150lc / 16lc) \u003d 6500lm.
But if the ceilings in the room were above half the meter, and the room was not "light", but the "standard" room with the reflection coefficients of the ceiling, walls and gender 50%, 30% and 10%, the utilization coefficient of the light flux η would be (cm . Extended version of the table) η \u003d 0.23, and the illumination would be smoothly twice as much!

Check the calculations in the Dialyux
We will construct a 4 × 5m room in the Dialyux, 2.8m height, with a height of working surfaces 0.8m and the same reflection coefficients as with a manual account. And hang 9pcs of small lamps with a classic cosine chart of 720lm each (6480lm on the circle).

Fig. 1 Taken for example Philips BWG201 lamp with light stream 720lm, and its classic "cosine" light distribution

Will we get the average lighting of working surfaces in 150lk, how did we appreciate manually? Yes, the result of the calculation in the Dialux - 143lk (see Riga2), and in an empty room without furniture and human figure - 149lk. In the lighting of the same values \u200b\u200bthat differ in less than 10% are considered coinciding.

Fig. 2 The result of the calculation in the dialyux - the average illumination of the working surface (with the reserve coefficient 1.0) was 143lk, which corresponds to the target value of 150lk.

Fig. 3 Beautiful pictures that believe people.

Conclusion:
For a rough estimate, the primitive method according to the formula E \u003d 0.5 × F / S will require 1 minute of time, to clarify the utilization ratio of tables - another 3 minutes, the project in the Dialyux after some training is about 20 minutes and another 20 minutes, if you want to "bring Beauty. " Dialyux issues very beautiful pictures (See Fig. 3) who have a spent labor, because people believe in them. But according to the ratio of efficiency and labor costs, evaluating the lighting of paint-out competing. The manual account is simple, reliable and effective as a spermnaya blade, gives confidence and understanding.

Instruction

Take advantage of a special formula for approximately calculating the lighting power. It has the form: P \u003d PS / N, where P is a specific power on lighting, measured in W / m2 (20 W / m2 - average), S - denotes the area of \u200b\u200bthe calculated room in square meters, N -. However, this calculation is able to give an approximate result. After all, the requirements for illumination different rooms Quite different, depending on the type of room itself (for example, in the corridor or light, you need less than in the living room). Also, the lamps depending on their type also supply a different amount of light (for example, luminescent and halogen).

For a more accurate calculation of the illumination of any room using the formula P \u003d PS / N, consider that the value P should be taken out of the average value (20 W / m2), and in accordance with the value of the specific power on the lighting for this type of room. There are special tables with calculating the performance indicators for lighting, taking into account the type of room and the type of lamps. They can be found on the Internet, on sites on this issue.

When calculating the capacity of the room lighting, take into account that it can be common - the main (chandeliers, suspensions, etc.) and local (lamps, brakes, floor lamps, dots, etc.). And when you need to calculate the illumination, regardless of whether you make the calculation of local or main lighting, you need to take into account that various lamps and lamps give different light threads, brightness, intensity.

For basic lighting, use chandeliers and ceiling lamps that have plaffers from opal or matte glass or lamps with matte glass. Light streams in them are soft, scattered. Such a light source can light up the whole room evenly.

If you want to achieve a reverse effect, use lamps that have reflective surfaces or use lamps with a reflective surface in such lamps. Reflective layers in them can be applied closer to the basement on the flask itself of the lamp. Use such a light to illuminate a certain apartment area.

Helpful advice

If there are people in the family who have a weakened vision, then when calculating, consider this by increasing the specific lighting power (P).

Related article

In any room for the health and performance of the person who in it in it is an important role playing lighting. Therefore, you should carefully choose the necessary configuration and the power of the lamps so that it is as comfortable and convenient to it.

Instruction

Apply this calculation formula:
P \u003d P * S / N, where S is the area premises, in m2, p - the specific power on the lighting of W / m2 (usually the standard value is used in the calculations - 20 W / m2), N -. This method is approximate, since premises Different destination requires different degrees of illumination, for example, to light up toilet it is necessary much less light than it is required for the living room. Also affects and used lamps, for example, halogen and fluorescent lamps have different type illumination.

Use to better calculate the illumination as a specific power not a classical value of 20 W / m2, and the value that is suitable according to the standard standards for the desired type of residential premises. So in the children's room you can install the incandescent lamp by 30-90 W, on 12-40 W, a room for 10 - 30 W,

Estimates of illumination, and other photometric values \u200b\u200b- are carried out taking into account the perception of radiation by the human eye.

As is known, the human eye perceives electromagnetic radiation, the wavelength of which is in the range of 380 nm - 780 nm.

Moreover, the sensitivity of the human eye (the ratio of the energy of radiation according to the estimate perceived by the light by man and objectively measured energy) depends on the wavelength. With a wavelength of 555 nm (green light), the sensitivity of the eye to the light radiation is maximal.

Light flow - This is a magnitude that characterizes the power of the light radiation in the perception of it with a certain averaged human eye with its (eye) sensitivity to radiation with a specific frequency. Currently, for accounting the last parameter, tables listed in the German standard DIN 5031 are used. The light stream is measured in lumens.

The light strength (I) is the light stream that spreads within the framework of any direction, that is, the private from dividing the light flux to the body angle, inside of which this stream is distributed (measured in candelas).

Illumination (EV) is a light flux divided by the value of the area on which it (stream) falls. The light is measured in suites, LC (1 luxury is 1 lumen / 1 square meter).

Brightness is the relationship of the power of the light created by the source to the area of \u200b\u200bthis source.

In the SI system - seven major units, including Candela. One watt of electromagnetic (light) radiation at a wavelength of 555 nm is perceived by the eye as 683 lumen. The KM constant, equal to 683 lm / W, is called the photometric emission equivalent coefficient.

Testo 545 Luxmeter. Light Measurement Device

What should be illumination

When calculating lighting indoors, it is necessary to determine the requirements for illumination at specific points of the room. These requirements are contained in regulatory documents:

• Sanpin 2.21 / 2.1.1 / 1278-03;
• SP 52.13330.2011.

It is important to understand that the lighting of the premises may not only be artificial, but also natural. However, we will not consider natural light in our calculations. The question is, of course, very important, especially when designing energy efficient buildings. But this is a question ratio of construction design. The amount, power and location of the lamps (even in the presence of windows) are still determined by the absence of natural lighting.

The requirements for the illumination of some typical species are located in Table 1.

Types of light sources

In addition to illumination requirements, the quality of lighting devices should be taken into account. For our eyes, the most pleasant and comfortable lighting - natural (day sunlight). And the main task of creating is the maximum approximation to the natural.

An important characteristic of the light source - colorful temperature (See Table 2).

Specifications of some types of lamps are shown in Table 3. The electrical power of the lamp is consumed from the network. electric power. The light stream is the "light power" of the lamp, i.e. the power estimated with the spectral sensitivity of the human eye. The ratio of these quantities is called "Light Departure".

Selection of lighting equipment

To calculate the illumination, the professional is most often used. free program Dialux. For those who use this program infrequently, in the standard installation there is a "Light" version.

However, this program and qualifications are not always in stock. In addition, it requires the descriptions of the description of the used lamps in IES Photometric Data File. It is supported not only by Dialux. Most professional programs that are used to calculate the room lighting (3D Studio, Lightscape, Relux, Cinema 4D programs, etc.), also use this standardized photometric format for presenting information about luminaires.

To calculate lighting manually used:

1. specific power method
2. method of use coefficient
3. point method.

Specific power method

This is the easiest method, the use of it is quite justified to assess the overall lighting.

To determine the required total power of the lamps, it is necessary to multiply the regulatory power (per unit area) to the area of \u200b\u200bthe room.

When determining the regulatory parameters, the purpose of the room is taken into account, the type of light sources, the distribution of the luminaires horizontally and vertical (examples - in Table 4).

The number of lamps and their location are determined on the basis of the calculated total total power, the power of the selected lamps and the conditions for creating the illumination of the most reasonable configuration.

Method of utilization rate

When designing a general lighting, the use of this method is fully justified.

First, the preliminary definition of the positions of light sources is performed. At the same time, the configuration of the room is taken into account, the possibility of reflection of light from the surfaces of fences.

The required light stream of one luminaire F is calculated by the formula:

F \u003d ensk marz / n η,

where EN is regulatory illumination, LC (according to the requirements of the joint venture and SanPiN); S - Area, square. m; KAZ - stock coefficient (the quatern value depends on the state of the lamps, enclosing surfaces, more - in Table 5); Z is the minimum illumination coefficient (approximately, for fluorescent lamps Z \u003d 1.1 for incandescent lamps Z \u003d 1,15); N is the number of lamps (usually approximately estimated on the basis of the analysis of the features of the room prior to clarifying calculations); η - The utilization rate of the light stream.

The coefficient η depends on the type of lamp, the index of the room I and the reflection coefficients: the RP ceiling, the walls RC, the floor RR.

Typical values \u200b\u200bof reflection coefficients are:

• for offices: RP \u003d 70%, RS \u003d 50%, RR \u003d 30%.
• for conventional industrial premises and workshops: Rp \u003d 50%, Rc \u003d 30%, RR \u003d 10%.
• for workshops with increased dustiness: Rp \u003d 30%, Rc \u003d 10%, RR \u003d 10%.

The index of the room I is determined like this:

where A, B, H is the horizontal and vertical size of the room.

Table 6 shows the values \u200b\u200bof η for the luminaire with fluorescent lamps:

After calculating the formula, we can pick up the lamp. If the task of selecting the lamp is not solved immediately, we repeat iterations, changing the source data until you select what you need.

Spot method

The method is quite universal and can be used for any mutual location Illuminated surfaces and light sources. To perform the calculation, illumination estimates are used at several points, which gets light from the lamps.

Location point lamps and graphics for round-summetic light sources

Lamps can be arranged in any way, can form any correct or incorrect geometric shape. For control, the illumination is estimated in the characteristic points for you.

The use of a point method is justified in rooms with equipment, dark walls and a ceiling, with a complex configuration. If you need to apply the point method, it may turn out that the development and use of specialized software will save time and strength.

Location of lamps on the first drawing of incandescent bulbs on the second - fluorescent lamps

Theoretical formula for calculating the illumination of the surface at the point is:

E \u003d iα COS (α) / R2,

where iα is the power of light in the direction from the source to the point (determined by curves or tables for the selected lamp), CD; α is the angle between the perpendicular to the surface and the direction to the light source; R is the distance between the source and the point, m.

In assessing the illumination of the point of the horizontal plane, the ceiling lamp, located at the height of H from the surface, the resulting formula can be rewritten in next formadapted for technical calculations:

E \u003d iα cos3 (α) μ / h2 kap

where - the coefficient μ is introduced to take into account the influence of the reflected light flow and remote lamps (usually μs in the range of 1.05 - 1.2).

We have already discussed the coefficient of the factory, considering the method of use coefficient. Definition of illumination is performed with the attraction of reference information, as a rule, graphics of spatial isolux are used (i.e., lines connecting equivocive points), as well as auxiliary tables.

How bright you want to illuminate the room? Take advantage of our recommendations to determine which power of the lamp must be selected to correctly light the room.

The dependence of the brightness of the illumination on the size of the room (for incandescent bulbs):

Room Square, sq.m:	Bright light	Medium light	Low light
1 sq.m.	20 W.	20 W.	15 W.
from 2 to 5 sq.m.	40 - 100 W	40-100 W.	20 - 60 W
from 6 to 9 sq.m.	120 - 180 W	100-160 W.	60 - 100 W
10 sq.m.	200 W.	180 W.	120 W.
12-14 sq.m.	240 - 280 W	200-240 W.	120-160 W.
15 sq.m.	300 W.	255 W.	160 - 180 W
20 sq.m.	400 W.	340 W.	220 W.
25 sq.m.	500 W.	425 W.	280 W.
from 30 sq.m.	from 600 W.	from 510 W.	from 340 W.

Take advantage of our calculator to determine which power should be light bulbs (for different types of lamps):

Lighting power calculator

On the indicators of stability and performance, as well as the health of any person, constantly or periodically located in one or another room, the illumination has a huge impact. Therefore, it is extremely important to choose such power lamps so that the illumination of the room is as comfortable and comfortable for people.

The illumination is called a physical value that is numerically equal to the light flow that falls per unit of the surface under consideration. Or, in other words, the illumination is a surface density of the light flow falling on the area. The luxury lights are measured.

As for the inner illumination of the premises, it is rigidly regulated today by labor protection regulations for any enterprise (in particular, SNiP 23-05-95). In this case, production premises must have natural lighting (for which they are equipped with windows), as well as a variety of sources of artificial light of sufficient power. There should also be an internal illumination of premises by no more than 5% lower than the outer illumination of the building.

In this formula: P - the specific capacity for the lighting of the room is measured in W / m2 (often used in calculations in this quality standard value, equal to 20 W / m2),
S - the area of \u200b\u200bthe room under consideration, measured in square meters,
And n - the number of fixtures installed here.

Naturally, this method is completely not accurate and has many errors. The results that can be obtained with it will be only approximate - if only because for premises for various purposes, the degree of illumination should also be different.

Moreover, different types LAMPS, which today there is a lot of, of course also have different lighting indicators. So, use the standard value of the specific power on the lighting equal to twenty, is simply inappropriate. In any case, when it comes to the use of LED modern sources of artificial light.

Thus, to calculate the illumination, both production and residential premises, provided that any type of lamps here: from ordinary incandescent lamps to LED, much more useful and more convenient to use our specialized calculator. In order for the illumination of one or another room, it is calculated correctly, you should specify the necessary parameters for the calculator.

Used when calculating the parameters, this is:

• the size of the room in which sufficient lighting is necessary. Length, width, height and reflection coefficients, walls and ceiling;
• lamps. The distance between any working surface and the light source, the lamp utilization factor:
• type and power of lamps;
• light norms for one or another room.

When calculating the illumination of the room, you should pay attention to the fact that the lighting is divided into the main and local. The main lighting is the upper light that gives lighting to the entire space of the room. Local lighting is the flooring, table lamps Or sconce, a variety of lamps. The intensity of the light flux, as well as the brightness and the power of light from different sources artificial lighting Significantly different from each other.

If we are talking about the illumination of residential premises, as sources of the main (or main) light, it is more expedient to use chandeliers and lamps with universal beams made of matte glass, which make the light slightly scattered and soft, evenly spreading it all over the room. But in the event that it is necessary to illuminate a separate part of the room, the ideal option A specially selected lamp can become a special lamp on the flask of which the reflective surface layer was applied. Lighting created by such a lamp due to this surface will be more local. If people with weak vision live in the house, it is also desirable to take into account this in the process of calculating the illumination of the premises, increasing the value of the required power of the light source.

High floor reflection coefficients, walls and ceiling contribute to creating comfortable conditions For work and life. When calculating the light, it should also be remembered that too strong intensity and the brightness of light poorly affects vision, and work, and to live in such a room will be difficult and uncomfortable.

Subject to a clear observance of all these requirements and nuances, you can make the most faithful and accurate calculation of the illumination of any industrial or residential premises, and based on it is optimal to choose types lED lampsthat will be installed in this room.