How to independently calculate the illumination of a room. How to calculate lighting using LED lamps

In the evening, with the onset of twilight, and if the windows are in an unfavorable position, during the day, you have to turn on the lamps, and the question arises: how to calculate room illumination to save on electricity and not sit in the dark.

How to calculate the illumination of a room correctly?

Comfort in the house is not only a pleasant microclimate, a pleasing interior and a crackling fireplace in the corner. When creating coziness, the correct distribution of lamps is of great importance in order to provide lighting that does not tire the eyes or soft twilight. IN big room zoning with the help of light sources is possible; in a small room, distributing them according to height levels may be sufficient, for example: a floor lamp, sconce and chandelier. But, in any case, you must insert the most suitable light bulb into each device. You'll have to choose from a dozen various options, so that it does not appear too bright or dull.

When choosing the optimal level of room lighting, you should rely on factors such as the presence or absence of mirrors, the color scheme of the room, the color of the furniture (dark or light). Even the height of the ceilings will play a certain role when choosing light bulbs for a chandelier. You should also remember that the lighting must correspond to the purpose of the room. In the bedroom the best option the light will be dim; in the office, a bright light bulb will only be needed in the area desk, in the living room it is better to use different variants. Illumination power is usually taken per square meter; an example can be seen in the table below.

Generally accepted standards of illumination at the height of the ceiling of the room no more than 3 m

The simplest way to calculate the illumination of a room is the formula P = (p . S)/N, wherein p is the specific power, usually taken to be 20 W/m2, S– area of ​​the room, and N– number of lamps. However, this formula will only give an approximate figure and will not reliably show the need to add or, conversely, reduce the brightness of the light. To begin with, the power density for each room is different, and can vary depending on what type of light bulb is inserted into the socket. You can verify this by looking at the table.

What should you consider when calculating the required brightness of lamps?

So, we looked at the simplest method for calculating the possible illumination power in a room. But, again, this is the total power. You can screw in 2 bulbs of 100 W or 4 bulbs of 50, distributing them over a wider front. What will change? Number of light sources. It is logical that by placing a two-armed and very bright chandelier in the center of the room, sitting with your back to it at the table, you will see your shadow on work surface. And it’s easy to guess that placing 4 lamps with a total power identical to the previous option different zones premises, including the work room, will give a much greater effect.

Before calculating the number of lamps, you should take into account the height of the ceiling and work surface. Above is a table of room lighting brightness standards for ceilings up to 3 meters. What if they are much higher? Then the same indicators should be multiplied by 1.5, and after 4 meters - by 2. Ideally, natural light sources should also be taken into account in the calculations, that is, but it is hardly possible to recalculate the number of lumens penetrating through them. But for lamps this is quite feasible if you use the table.

Therefore, let us not pay attention to external factors, but on the internal ones, that is, on the light of the lamps and its interaction with the finish. Matte finish furniture and walls tend to absorb light rays, and glossy materials, as is known, reflect them. It's the same with colors; darker ones require brighter lighting and vice versa. The specific power from the formula given earlier must be taken based on all the listed factors, and the following table will help with this.

How to calculate the number of lamps per room?

So, we know the height of the ceiling, let’s say 3.2 meters, in our office we have a table 80 centimeters high. How to determine how many light sources are needed? There's no way around this anymore simple method, and therefore we will use more difficult option, which will require a number of formulas. And you will have to operate in addition to Watts with such units of measurement as lux and lumen. First of all, we calculate the area of ​​the room using the standard method S=a.b, Where a And b– lengths of adjacent sides of the room. Let's say the required value is 12 m 2.

Next we need to find out the utilization factor of the lighting fixture, for which we need the room index and reflection coefficients various surfaces. The formula to obtain the first indicator is as follows: φ=S/((h1 - h2) ∙ (a + b)). Here two new variables are added, h1 And h2, representing the height from the ceiling to the floor and from the ceiling to the illuminated working surface of the table. As for the coefficients, they depend on what material the surface is made of and what texture it has. Suitable values can be selected from the table.

It is usually customary to take reflectance coefficients for the ceiling, walls and floor (they are converted to decimal fractions, that is, a value of 50 corresponds to 0.5). Based on them and the result of calculating the room index, it is not difficult to find another variable - the lighting use index U, which we will need for further calculations. The next coefficient is determined from tables, which differ significantly depending on the use of a particular brand of lamp. Let's take, for example, lamps with type KSS M, that is, a wide spectrum of illumination within 180 degrees of maximum brightness. This is just an ordinary household light bulb.

Having learned the meaning U, then substitute it into the formula N=(E∙S∙100∙K h)/(U∙n∙F l). We have new variables in the numerator: E– minimum illumination, expressed in lux (lx), and K z– safety factor taken into account based on the aging of light bulbs during operation. The latter is, in fact, a constant that can be found in SNiP, but on average this figure corresponds to 1.5 for fluorescent lamps and 1.3 for incandescent lamps. The denominator is unknown to us n– the number of light sources in the electrical appliance and F l– radiation from one lamp, expressed in lumes (lm). The minimum illumination value is calculated using the formula E = F l /S. Using all the parameters given in the tables, as well as the results of secondary formulas, find the number of lamps N the room will not be difficult.

No matter how many bulbs there are in a chandelier, it cannot illuminate the entire room; darker areas will certainly remain somewhere, so it is wiser to distribute the lighting sources throughout the room.

Right organized lighting in your home not only helps maintain eye health, but also creates convenience and comfort in everyday life. It is therefore very important to approach your home or apartment responsibly in order to subsequently select the right lamps, chandeliers and lamp power for them.

When assessing lighting Several parameters are used - luminous intensity, brightness, etc., but the main one will be illumination, which means the amount of illumination of the surface over which the luminous flux is distributed.

Used for calculations physical quantity illumination measurements - Lux (lux or international designation - lx). One Lux is equal to the illumination of a surface of 1 m² with an incident luminous flux of radiation equal to 1 Lumen, which is denoted lm or lm and is a unit of measurement of luminous flux.

How to calculate the required level of illumination.

For approximate calculation for the required power of lamps, I recommend using the formula: P=pS/N, where p is the specific lighting power per square meter. This value will be different for each type of lamp and room; it can be found in the table below.

Value S is the area in square meters for the calculated premises, and N is the number of lamps. A toilet or hallway needs less light than, say, a living room. In addition, lamps, depending on the principle of operation, also provide different amounts of light (for example, halogen and fluorescent lamps).

When making calculations it is necessary take into account the distance of the light source from the surface it illuminates. Know that its illumination decreases inversely with the square of the distance.

According to numerous studies and standards in force in the Republic of Belarus, the overall illumination of the room should be within about 200 Lux, and the illumination of the working surface area of ​​the table should be about 500 Lux.

So, now knowing all the parameters let's move directly to the calculations using the example . For a bedroom with an area of ​​10 square meters, we multiply 10 by the coefficient for this room 10-20 and get 100-200 Watts (incandescent lamp power). But don't forget that this power value will apply to one lamp installed in the center of the ceiling.

It's still simplified the average calculation does not take into account many factors such as the color and tone of the walls, floor, ceiling, which significantly affect a person’s perception of the amount of light in the room. So for rooms with light-colored furniture, walls, ceilings, etc., the value of 200 Lux in calculations can be reduced by more than 2 times.

Determine the required level of illumination Depending on the area of ​​the room, the table below will help you.

Note: the table shows optimal values to determine the required level of lighting power when installing incandescent lamps as the main light source in the center of the room. When installing fluorescent lamps, the power of the lamps should be reduced by 5-7 times, and LED lamps by 10 times. You can determine more accurately by looking at the packaging for the lamps, on which, as a rule, the manufacturer indicates how many incandescent lamps one energy-saving lamp replaces.

I hope that you have received an approximate idea of ​​​​how to independently make the required calculation parameters for your apartment or house. Keep in mind that bright light is needed for work and reading, and for relaxation you need softer and non-irritating light.

How to determine the light level.

A special device, a lux meter, consisting of a photocell and an indicating device, will help to accurately determine the actual level of illumination for each specific case. The photo sensor converts the energy of the light flux into electrical energy, the magnitude of which will depend on the intensity of the incident light.

The device is quite easy to use:

1. Turn it on.
2. We place the lux meter at the point on the surface required for measurement.
3. If necessary, turn on the required measurement mode.
4. We set measurement limits.
5. We take readings.

Unfortunately, prices for lux meters are still quite high. In Minsk, prices start from 70 USD. e.

Similar materials.

Purchase new apartment or renovating an old home is a great way to reconsider your attitude to the topic of lighting and abandon traditional massive chandeliers and incandescent light bulbs.

Modern housing design and possibilities construction technologies allow you to come up with and implement any lighting schemes depending on the purpose of the room. The main pleasure is that everyone can choose the type, quantity and power lighting fixtures to suit your lighting level requirements.

But besides our desires, there are norms and requirements that must be adhered to.

Requirements and wishes for lighting arrangement

Before you begin planning and calculating the lighting system of a room, it is necessary to formulate what basic criteria it must meet.

The main ones are:

• Comfortable illumination, that is, light enough for reading, communication, homework, but does not hurt the eyes. This indicator is different for everyone, as it depends on the state of vision, habits and preferences.
• Convenient placement of lamps that should provide light to the entire area of ​​the room, but the level of illumination may differ depending on different parts rooms.
• Cost-effectiveness, namely, the amount of the monthly payment for electricity, the cost of the light bulbs themselves (for one and for the entire number), the service life of the light bulbs (how often they will have to be purchased).

If we take into account all these requirements, then the optimal solution will be to choose LED lamps. In terms of light level, they are equal to incandescent lamps, but they consume significantly less electricity and last for several years. Compared to energy saving fluorescent lamps LED analogues differ more compact shape and a pleasant glow. Now it is necessary to calculate the illumination of the room with LED lamps in order to calculate how many and what power of lamps is needed for sufficient lighting.

What data is needed to calculate the illumination level

There are several ways in which you can calculate the number and power of LED lamps. Before you begin the calculations, you need to figure out what indicators will be involved in them.

List of variables and constants on the basis of which the calculation is made LED lighting, consists of the following points:

• The area of ​​the room, that is, the product of the length and the width of the room. Calculations are made based on the fact that the room has a rectangular shape. With more complex architecture, it is necessary to conditionally divide the space into regular figures and add up their areas.
• A correction factor that takes into account ceiling heights. Since light spreads not only over the area, but throughout the entire volume of the room, the brightness of the lighting directly depends on the height of the ceilings. Use a special table of coefficients. For example, a ceiling height from 2.5 to 2.7 m is a coefficient of 1, up to 3 m is equal to 1.2, up to 3.5 m is 1.5, then an adjustment indicator of 2 is used.
• Another standard is the level of illumination, for the calculation of which special tables have also been compiled for residential, utility, commercial and production premises. The indicator is measured in Lux (lux).

The most popular indicators are as follows:

1. bathroom, toilet, basement, corridor are equivalent to utility rooms, and the level of illumination in them ranges from 20 Lux (in the basement) to 50 Lux (in the corridor).
2. living rooms are estimated in the range from 150 to 300 Lx, the minimum level in the bedroom and kitchen is 150 Lx, the maximum level in the study and children's room is 300 Lx.

Additionally, the following indicators can be used in calculations:

• cleanliness of the room (dust level);
• finishing materials and ceilings (dark, light, glossy).

The easiest way to calculate room illumination with LED lamps

The easiest way to calculate the illumination of a room with LED lamps is as follows:

Let's calculate the required amount of luminous flux (in lumens).

To do this, simply multiply the known quantities:

room area × illumination standard × correction factor for ceiling height.

For example, the room area is 15 m², the ceiling height is 2.5 m, which means the coefficient equal to one, room - kitchen, for which the illumination standard is 150 lux

As a result we get:

15 × 150 × 1 = 2250 lumens(lm).

The second step in the calculation is to calculate the number and power of LED light bulbs. Here you can do two opposite things.

1. Divide the total luminous flux by the lamp wattage to get the number of lamps. However, the luminous flux power is usually indicated on the packaging of the light bulb, and it does not equal power. For example, a 10 W lamp produces 800 lumens. That is, as a result we get 2250 / 800 = 2.8 or 3 lamps.
2. Another method of calculation is more justified. The calculation is based on the number of lighting points installed in the room. For example: 2250/6 lamps = 375 lumens. This flux is produced by 5 W lamps.

With the latter type of room, an increase in the number of lamps of lower power leads to a more uniform distribution of light throughout the room.

More complex and accurate calculation of illumination

In professional calculations, a more complex calculation method is used, which is used for lamps of all types. General principles calculations in both methods are the same, but for greater accuracy additional coefficients are taken into account, such as:

• k is a safety factor that takes into account the dustiness of lamps and the deterioration of their ability to transmit light, the decrease in the level of luminous flux from the lamp over time, and the deterioration of the reflectivity of walls and ceilings. Since LED lamps have a long service life without deterioration in quality, their safety factor is 1.1.
• z is an indicator of the ratio of average illumination to the minimum Eср/Emin, that is, unevenness of the illumination level. For LED lamps, due to their even glow, this indicator is 1.
• Φ is the luminous flux of LED lamps, Lm, which can be found on the packaging or from the accompanying documentation for the lighting lamps.
• η is the coefficient of utilization of the luminous flux, that is Source efficiency lighting. In highly efficient LED lamps it is almost equal to 1.
• E - standard illumination in Lux, from tables or directly from SNiP.

Also, in a complex calculation, the corrective ceiling height is calculated more accurately. To calculate it, determine:

• h - total height of the room
• h1 - length or height of the suspension of the ceiling lamp
• h2 - height from the floor to the main working surface (table, bed)

This complex calculation is made based on the fact that in most cases the light source is located below the ceiling, and the highest level of lighting is required not at floor level, but at the height of the working surface.

The calculation formula is as follows:

hp = (h – (h1 + h2)), where hp is the estimated height of the room requiring lighting

This indicator, along with the length, width and total area, is involved in the calculation of the room index, that is, the geometric characteristics of the room.

The formula for the index (i) of the premises is calculated as follows:

i = S / (hp × (a + b)), where a and b are the length and width, and S is the area.

As a result, the general formula for calculating the illumination of a room with LED lamps and determining the required number of lamps is as follows:

N = (E × S × k × z × 100)/(n × Ф × η)

Such complex calculations are usually made during the design and development of a room. technical characteristics. In everyday life, simpler methods are used.

Calculator for calculating lighting with LED lamps

To determine the number of LED lamps and their power for a specific room without hassle or difficulty, you can use the “lighting calculation” calculator LED lamps" After the command calculate software will do everything independently necessary calculations and will give you the finished results. With the data received, you can go to the store to buy lamps or place an order here on the website.

The calculator is under development, we hope for your understanding!

Video on the topic

Properly selected lighting plays a big role for a person. An optimally selected light flux will give the room a finished look, help hide or, conversely, highlight individual interior details.

In addition, the level of comfort of the people in it depends on the lighting power of the room. So the issue of lighting is not in last place, and requires competent calculation.

I want to say right away that there is no exact formula for this kind of calculation. There are many criteria that can directly or indirectly influence this indicator.

Therefore, within the framework of this article, we will not delve into the study of SNiP and use complex and detailed methods. Let’s use a slightly simplified and quick method for calculating illumination.

Video: Education about illumination

As a result, you will have an understanding of how many and what lighting elements (approximately) will be needed for a separate room or space. All our mathematics will take place in two stages:

1. We calculate the required luminous flux;
2. calculation of the number of lamps.

The amount of luminous flux is measured in lumens and denoted “Lm”. Illumination is measured in lux, designated “Lx”.

Calculation of luminous flux

The simplest formula will look like this: P = a × b × c. Where P is the luminous flux, a is the illumination value of the room, b is the area of ​​the room in m², c is the ceiling height coefficient.

Correction factors for different ceilings are known and have the following meanings:

• height up to 2.7 m = 1;
• from 2.7 to 3 m = 1.2;
• from 3 to 3.5 m = 1.5;
• from 3.5 to 4 = 2.

Standard value of illumination according to SNiP:

So, let's determine the amount of luminous flux for a living room with an area of ​​10 m² and a ceiling height of 2.60. Illumination rate 150 × 10 m² × 1 = 1500 Lumens (Lm).

Calculation of the number of lamps

We make a calculation. We have already calculated the amount of luminous flux, and we know that it is equal to 1500 lumens. We select a lamp from the table above; let’s take a 60-watt incandescent lamp as an example.

Its luminous flux is 800 lm. Now, we divide 1500 by 800 and we get that to illuminate one room you will need 1.8 light bulbs, round up to 2.

However, you need to understand that these are all approximate values. After all, the lighting of a room is also influenced by the type and color scheme of the room, the number of windows and much more.

Room parameters

Here it is worth considering not only the area of ​​the room, but also the height of the ceilings, the color of the walls and floors. The further the light source is from the illuminated surface, the less it will be illuminated. It is known that light is reflected from a surface; the lighter it is, the more light is reflected and vice versa.

Reflected light also illuminates the room. So, if the room is decorated in dark colors, you need to increase the luminous flux value when choosing a lamp.

In addition to all this, we do not forget that lighting can be general - chandeliers, etc., as well as spotlights - floor lamps, sconces, desk lamp and other lamps. And each of them shines differently.

On a note! All of the above calculations do not allow us to calculate the exact illumination power and are approximate, and are used, so to speak, for a general idea.

It is recommended to increase all norms and calculation results by 1.5 - 2 times. In this case, you can install several lamps with separate switches, dividing the space into zones. If necessary, by turning on some of the devices, you can get a soft and dim light, and with all the devices turned on, you get a brightly lit room.

Video: How much light or room lighting is needed!

The whole calculation takes 2 minutes, 2 steps. Everything is fast and simple!

Dear readers, in this article we will not provide detailed, complex methods for calculating room illumination, and we will not force you to carefully look at SNIPs and tables in search of the necessary coefficients. We will tell you as approximately as possible using a simplified quick technique, calculate the required illumination of the room (room), as well as how to calculate the number of lamps required for comfortable lighting.

First, we need to know that illumination is measured in lux (Lx), and the amount of luminous flux is measured in lumens (Lm). Again, this method of calculating illumination allows us not to understand the relationships and intricacies of these quantities. Let's approach this simply - we need to know this in order to choose the right lamps and the number of lamps for the room (room).

Calculation steps:

1. Calculation of the required luminous flux per room (number of lumens for the entire room).
2. Calculation of the required number of lamps per room (room).

1. Calculation of the required luminous flux per room (room).

Formula for calculating luminous flux in lumens (Lm):
Luminous flux (lumens) = A * B * C;

Where:
A- the standard value of room illumination is presented in the table below;
B- area of ​​the premises (room) in square meters;
IN- ceiling height coefficient (up to 2.7 m - 1.0; 2.7-3.0 m - 1.2; 3.0-3.5 m - 1.5; 3.5-4.0 - 2 ,0);

2. Calculation of the required number of lamps per room (room).

So, we have determined the required amount of luminous flux (the number of lumens). Now we can calculate required amount lamps per room (room). Below is a table in which you can select the number of lamps for a room (room) and compare the main popular types of lamps according to their luminous flux characteristics and power ratio.

All these calculations are approximate and are suitable for selecting a chandelier or lamp placed in the center of the room.

If you want to understand how many spotlights with LED bulbs are needed, it is better to proceed from the calculation of one lamp with a power of 5-7 W (450-550 Lm) per 1.2-1.5 sq.m.

Table No. 1: Standard values ​​for illumination of premises/rooms, according to SNiP:

Table No. 2: Average luminous flux by type of light bulb (number of lumens).

The data presented in the table is approximate; depending on the manufacturer, it may differ.

A few more small tips on calculating the luminous flux and choosing the number of lamps:

1. Remember that SNiPs were developed in Soviet times. At that time, they didn’t really care about the health of citizens (meaning their eyes), not to mention the comfort of staying indoors or working in it. So it’s a good idea to add a small safety factor to the calculation of your illumination (luminous flux).
2. If you have more lamps in your room than you need, you can always turn off some of them. What will you do if there is not enough light, and what will it look like?
3. Remember that surfaces tend to reflect light. The lighter the surface, the more light it reflects; the darker it is, the less light it reflects. Light that is reflected from a surface is also light, i.e. reflected light also illuminates the room. If dark colors predominate in your room or premises, it is worth increasing the luminous flux value when selecting lamps, since dark surfaces of the room will absorb a large number of Sveta.

Table No. 3: Light reflectance.

If you need to calculate the illumination and number of lamps for a non-standard room (with very high ceilings or intricate shapes), or you need to select high-quality lighting fixtures for a room, home or office, call us and our specialists will provide comprehensive information and offer a solution.