The construction of any buildings and structures, as well as almost all design projects, include the stage of lighting calculation. Despite all the achievements in this area, nothing can compare with a natural source called the Sun! We can only get as close to it as possible in order to provide our homes with the necessary level of comfort. But how to calculate the illumination of the room?
This matter should be approached with maximum responsibility, although better than necessary, it may still fail. But in any case, a more or less positive result will still be achieved.
Factors to Consider
Despite the fact that a better option than natural lighting has not yet been invented, artificial sources with a competent approach to business can give no worse results. When calculating the illumination, the type and area of the room should be taken into account. At the same time, other factors need to be taken into account:
- Functionality of the room.
- The height and color of the ceiling.
- Texture and shades of the walls.
- What flooring is made of, as well as its parameters (texture, color).
- The presence of mirror furniture.
- Are there large mirrors in the room?
- The number of pieces of furniture and their color scheme.
All this has a significant impact on the choice of type and number of lighting fixtures for the room. The essence of the calculation of illumination is to calculate the maximum power of the devices used and their number, including the parameters and number of lamps themselves.
Comfort indicators
How to calculate the illumination of the room? Norms will be given a little later. In the meantime, consider a number of important points. The required level of comfortable lighting will largely depend on the purpose of the room. That is, the best option for the kitchen will seem too bright in relation to the living room or bedroom.
Also, do not neglect the height of the room. Usually, according to the standard, it is 2.5-3 meters, but it can be more - from 3 to 4 meters, if not higher. In this case, special coefficients are used. They will be considered a little later. The presence of mirrors and the color scheme of the room are also taken into account using their own coefficients and indices.
With such accounting for little things, the calculation of lighting can drag on for a fairly long period of time. Typically, such operations are carried out by professional designers. But ordinary residents who want to do everything themselves, such excesses are useless.
Room Lighting Standards
Before you consider what methods of calculating the illumination you can use, it is worthwhile to start with certain standards. In accordance with building codes and rules (SNiP) the following values are used, measured in suites:
- General purpose offices where computers are used for work - 300 Lx.
- Offices in which they work with drawings - 500 Lx.
- Conference halls, meeting rooms - 200 Lx.
- Escalators - 50-10 Lux.
- Archival premises - 75 Lx.
- Pantries, utility rooms - 50 Lux.
- Kitchens, living rooms - 150 Lx.
- Children's rooms - 200 Lx.
- Toilets, bathrooms, showers, apartment corridors - 50 Lux.
- Dressing rooms - 75 Lx.
- Classrooms, libraries - 300 Lx.
- Stairs - 20 Lx.
- Saunas, pools - 100 Lx.
Now, according to the above standards, it is not difficult to calculate the illumination for each individual room. At the same time, it is worth considering that these standards have been used in our country for quite some time.
Therefore, it is not surprising that many people complain about the lack of light, although the calculations were performed correctly. In this regard, it makes sense to replace the lamps with more powerful options or increase the number of lamps.
Features of the choice of lamps for fixtures
To create the optimal level of illumination, you should pay attention to what light sources are used in lighting devices. If a few decades ago the choice was limited only to incandescent lamps of different capacities, now the assortment has increased significantly. What can the modern market offer us?
LED bulbs
Without a doubt, such light sources can be called environmentally friendly, since safe components are used for their production and during operation. They do not contain mercury vapor, and therefore, in case of damage to the housing, such lamps do not pose a threat to humans or the environment.
How to calculate the illumination of a room with LED lamps? Before that, you should learn about the advantages of LED lamps, as well as get acquainted with other light sources. The obvious advantages of economical lamps:
- Low power consumption.
- A long period of operation - according to many manufacturers, the resource of LEDs is from 30 to 50 thousand hours of continuous operation.
- The case is reliably protected from mechanical damage.
- The lamps can be absolutely any size and shape, including very compact dimensions.
At the same time, there are disadvantages, but they are not so significant. And the main one that inhibits their mass distribution is the high cost. In countries with a low cost of living, the population simply does not have enough funds to purchase LED lamps for a house or apartment.
The state, in turn, does not seek to modernize street lighting with economical in every sense light sources.
Halogen lamps
For methods of calculating illumination, which will be discussed a little later, halogen lamps will be the best alternative to conventional incandescent lamps. Moreover, they have a structure similar to them, only the bulb contains gas. As a rule, these are pairs of bromine, chlorine, fluorine, iodine, which significantly increases the resource of the tungsten filament (its heating is about 3000 K) up to 2000-4000 hours.
Such lamps are often used as local lighting in spotlights or table lamps with appropriate sockets and operating on alternating or direct current. Only when using it is necessary to apply a smooth start, and then the resource of halogen lamps increases markedly up to 8-12 thousand hours.
If we compare the power of the "halogen" with conventional incandescent lamps, then this characteristic can be 150-230 watts. This option is relevant for spotlights, lamps. They can also be used to dry various materials in production.
Fluorescent lamps
The calculation of the illumination of the room with lamps may include such an optimal option. In everyday life, they are usually called fluorescent lamps. They also have a glass flask, on the inner surface of which a layer of phosphor is applied. The tank is filled with vapors of argon and mercury (this is called an amalgam) at a pressure of 400 Pa. As a result, ultraviolet radiation is created.
As for light output, this parameter significantly exceeds the value of a conventional incandescent lamp. And the service life in high-quality production can be up to 5 years.
Fluorescent lamps are also divided into subspecies - with high and low pressure. The first to light the streets, roads, as they have great power. Low-pressure lamps are installed in lighting fixtures in industrial or residential premises.
Due to the brightness and efficiency, such light sources are widely used in general purpose offices, hospitals, schools, and children's institutions. And if earlier such lamps were made in a single configuration and required special lamps, now a wide variety of models are on sale. They are equipped with the most popular socles - E14 and E27. In this connection, they can be a good alternative to Ilyich's bulbs.
Methods for calculating room illumination
Now, in fact, as promised, we will consider methods that will help to understand how to calculate the illumination of a room by area or other parameter:
- Calculation of electrical power (in watts).
- Calculation of light power (in Lumens).
Each of the above methods differs in its formulas, norms and units.
Calculation of lighting by power in watts
This is the simplest method for calculating the lighting of a room , but at the same time it is far from the most accurate. The required initial data in this case is the area of the desired premises and the required capacity per 1 m 2 .
With the calculation of the area of the problem should not arise - the formula is familiar to everyone from school. As for the required power, then this parameter is different for each room (W per 1 m 2 ):
- living room 10-30;
- kitchen 12-35;
- Bathroom 10-25;
- bedroom 10-29.
The listed power indicators relate to standard incandescent lamps, since they are quite widespread throughout the world.
Power calculation in Lumens
How to calculate the illumination of the room? The formula in this case will be:
SP = A * B * C
SP is the light flux, A is the norm of illumination of the object, B is the area of the room, C is the coefficient of the height of the ceiling. Lighting standards have already been given in the section above.
There should not be a problem with calculating the area of a room. The ceiling height factor remains. It depends on the following height parameters: 2.5-2.7 m - 1; 2.7-3 m - 1.2; 3-3.5 m - 1.5; 3.5-4.5 - 2.
After that, you can proceed to determine the number of light sources. For this, the value of the luminous flux obtained during the calculations must be divided by the value that is usually indicated on the selected lamps.
Calculation Example
For a better understanding of the essence, consider one example of calculation for a living room. Initial area - 20 m 2 , ceiling height - 2.7 m, incandescent lamp power - 60 watts.
First you need to determine the power of the light flux for this type of room:
SP = 150 * 20 * 1 = 3000 Lumens.
After solving a problem that allows you to learn how to calculate the illumination of a room, it is worth determining the optimal number of light sources. And first of all, it is necessary to clarify the luminous flux characteristic of a 60 W bulb. Their average value is 600-800 Lumens. Take the middle ground - 700 Lumens. Then the number of bulbs (N) will be equal to:
N = 3000: 700 = 4.28571
The resulting value should be rounded up - 5. At the same time, it should be noted that using more bulbs with less power will allow you to get uniform lighting.
Inaccuracy when using LED lamps
Often during a scheduled repair, ordinary incandescent bulbs are replaced by an LED version. However, one problem may arise - there is clearly not enough light. How to calculate the illumination of the room and prevent such problems? All factors should be taken into account, and in this case, the reflection coefficient of the surface was not taken into account.
Changing wallpaper from light tones to darker shades, using linoleum or laminate (also a dark shade), a dull suspended ceiling - all this can cause insufficient lighting in the room.
If you turn on a table lamp with an LED above the table, then this lighting will be quite enough for reading or other work. However, if you want to lie on the sofa with your favorite book, he will obviously not be enough. And this not only creates a feeling of discomfort, but also adversely affects vision.
Reflection coefficient depending on the shade of the surface:
- white - 75%;
- light - 55%;
- gray - 35%;
- dark - 15%;
- black - 0%.
The total reflection coefficient of the room will be calculated by the formula:
To about = To OP + To OS + Konp / 3
To - the total reflection coefficient, To OP - the reflection coefficient of the ceiling, To OS - the reflection coefficient of the walls, Conp - the reflection coefficient of the floor covering. The result is an average value, which should be used in the calculations. And now, armed with the information received, anyone can understand how to calculate the illumination of the room.