How we made a smart office lighting system: compare two floors
A significant part of the electricity in the building is spent on lighting. At the same time, we often illuminate empty rooms and do not turn off the light during the day, when it is bright.
At CROC, right at the office itself, the systems we are going to deliver to customers run in, so the field for the experiment was excellent.
For comparison, two floors were selected with identical placement of fixtures and the location of the working premises. Sensors of automatic lighting control were installed on one floor, and the lamps were replaced with energy efficient ones with increased efficiency. Power was turned off in rooms without people, plus the level of brightness of the light was reduced with sufficient daylight.
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I'll show the result right away: in the end, we received a saving of 45% on a floor of just over 1,300 square meters. This is based on the human factor (selective shutdown of automation for your own comfort). Of course, the savings are not only due to the control of lighting, but also due to the replacement of lamps and the general modernization of lighting. Total, the payback period of the system, taking into account all the hardware and work - 5 years. The measurement was conducted from November 2, 2012 to March 30, 2013 (in the summer, with a larger light day, power will be needed even less, that is, the results will be better).
Diagram of the optimal mode of operation of artificial lighting in a typical room with windows (vertical - the intensity of the glow of lamps, horizontal - the clock).
The seventh floor of our first office building (KROK-1) wanted to be changed while still designing the internal engineering systems of the KROK-2 building under construction. The point is that KROK-2 is conceived as an energy-efficient building and this requirement imposes a certain framework on the entire engineering infrastructure.
The task was simple: to provide high-quality and convenient lighting for office staff while minimizing the electrical power supplied. We decided to analyze on the basis of two floors of the first building. The test was the seventh. The sixth floor of KROK-1 with the existing traditional lighting system was chosen as the control one for the premises, squares and saturation with the employees. And there, and there we assembled accurate counters for detailed accounting.
On the seventh floor also:
Many Western manufacturers of lighting control equipment show rather seductive savings in their brochures. Sometimes these indicators of savings are checked in practice in Russian realities, sometimes not, sometimes they are written for ideal conditions without taking into account the “human factor” (more on this later). As a result, indicators from 20 to 50% of the decrease in energy consumption for lighting appear in different sources.
At first glance, what could be simpler than turning off or dim the light when it is not needed? The only question is how and who will determine when it is “necessary” and when it is not. We decided to try the solution from Esylux to control the lighting in a completely autonomous mode, evaluate the savings and, having our own expertise and experience, and then offer it to customers.
To begin with, we recalculated the number of luminaires and optimized their placement to provide the necessary illumination at work sites, taking into account the installation of new luminaires. It was important to take into account the characteristics of new lamps, plus to make the redistribution of groups of lamps to control depending on the light from the windows (put them parallel to the glazing line). Then it was necessary to mount sensors that automatically control the lighting depending on the presence of people, as well as having the function of controlling the intensity of the glow of the lamps depending on the conditions of natural light.
The preparatory part was like this - at workplaces, measurements were taken with the aid of a luxometer and checked against current regulations. It should be noted that to a greater extent these measurements were of an informative nature, and as a result, the lighting was adjusted to the wishes of the staff. For each particular workplace, adaptation according to the level of natural light was made according to measurements of illumination, according to the wishes of the employee (I’ll say this later) and according to the characteristics of the furniture in the room.
Presence sensors with dimming function (smooth power control) were selected as control elements.
New types of luminaires and their placement, taking into account the staff seating, allowed us to change for the better the picture of the distribution of illumination at all workplaces, reduce power consumption on the floor by about 40%, which ultimately affected the electricity consumption of the seventh floor as a whole compared to control sixth floor (about 45%).
The benefits of simply turning off the light and the typical sensor operation depending on the daylight can be seen in the image (the light is turned on only when people are in the room):
If we also apply dimming, we get the following picture (even greater savings, the brightness of artificial lighting is adjusted depending on the natural):
One of the indirect advantages was that everyone got used to it very quickly, that there is no need to use switches, the light is on, where it is needed, where there are people, and just as intensively as it is needed.
Among the drawbacks, it can be noted that in bright sunshine, some clouds and strong winds, it may turn out that the sensor constantly clicks the light, some employees are annoyed and it is necessary, at least for a while, to switch the system to semi-automatic mode. This can be attributed just to the “human factor” mentioned at the beginning: any system should not be done to the detriment of the convenience of the people using it, so ways are provided consciously to turn on the light for a long period of time by turning off the automatics. It is clear that this is done at the expense of savings.
The experiment was carried out on a lively working team (all participants in the experiment, thanks for your understanding and patience) and the conditions to which everyone had time to get used changed. In each particular case, the wishes of the employees themselves were taken into account: someone loves brighter, someone is darker, someone practically does not use general artificial lighting and is treated with a desk lamp. This also played a role in estimating savings: with standardized settings, for example, in a new building where no one ever worked, everyone would immediately get used to the new conditions and it can be assumed that the savings would be greater.
In our case, sensors with an infrared sensitive element are used. Motion and presence sensors have the same principle of determining the presence, based on the difference in temperature of the human body and the environment.
I think everyone is familiar with these things - they are often found in hotels, for example.
In fact, the sensor responds to changes in the temperature of the observed space. At the “iron” level, this is realized with the help of a special lens, which consists of alternating transparent and opaque areas - as a result, it allows to divide the entire observed space into segments, at the border of which objects with a temperature different from the surrounding environment provide the response of the IR sensor . In this principle, one of the features of the sensors is hidden - they define the person worse when the sensor is moving on the sensor than the person walking along the tangent.
In the illustration below, a red person will be determined from a noticeably smaller distance than gray. The fact is that when moving to a sensor, a person can get into one sector and remain in it, despite the movement, until he overlaps the next one by increasing his “shadow” on the sensor. In the case of movement on a tangent, the person will cross the zones much faster and significant movements from sector to sector will be determined from a greater distance.
A feature of the sensors used is the ease of installation, even in an already mounted and working lighting system. Sensors are installed "in the gap" line and control the on-off using its own solid-state relay. The image shows the electrical circuit of switching on the sensor in line with the luminaire in case of control by a signal of 0..10V.
There are two main types of sensors:
The first is designed for periodic appearances of people, the second - for the constant presence of people and the measurement of the level of illumination.
At the same time, it is necessary to understand that both those and those sensors are formally determining movement, the names of “movement” and “presence” are used by the manufacturer for classification by application zones.
The main difference of motion sensors is in the algorithm for measuring illumination and control. They measure illumination only at the time of the first motion detection. For example, imagine a situation - the entrance to the shopping center, the lamp above it connected through this sensor, the sensor has a response threshold for example 250 lux and a shutdown delay of 2 minutes.
If a person enters the building early in the morning, when the sun has not yet risen and the level of natural lighting is less than 250 lux, the sensor detects the presence, measures the illumination, compares it with the threshold, closes the internal relay and turns on the lighting. If during the delay period of 2 minutes no one appears in the field of view, the light will turn off. If, in two minutes of delay, the next visitor has time to pass, the sensor will count two minutes from zero, without re-measuring the illumination. As a result, if the sensor does not measure the level of illumination, it may happen that the light does not turn off, despite the fact that the threshold has long been exceeded.
The presence sensors, in turn, measure the illumination constantly and compare it with the set value and are able to turn off the lights when the threshold is exceeded, even if the presence of people is detected
We mounted them in the corridors and public areas. It turned out to be a good idea to turn them on in parallel, so that when a single light is triggered, the light will turn on throughout the corridor.
Compact presence sensors are installed in the bathrooms and in the kitchen, the sensors have the same algorithm as the motion sensors in the corridors and public areas, but smaller sizes and coverage area.
Another problem was revealed in the bathroom - the person doesn’t run around the room very much (there is almost constant movement in the office premises, for example, moving the mouse), so the light can turn off unexpectedly. It is clear that in this case it will move, and the power will turn on, but, you see, it is not very comfortable. Therefore, we put up big shutdown delays for such sensors - from 15 minutes.
In office areas and in elevator halls, we mounted presence sensors and switches. The switch can turn off the power to the sensor and the entire control group lighting.
When turned on, the sensor is automatically calibrated for 10-15 seconds, then the light turns off and the configured algorithm starts working:
Our western colleagues install such systems in hotels (this is convenient for the guest and very practical), in offices, in manufacturing, in various public buildings, from city administrations to museums, and so on. Sometimes these things are put in houses.
In Europe, the main motive is “green technologies,” with us, I think, savings will play a big role.
From my own experience, we can say that the lighting control described in the above gives you the opportunity to forget about the switches and to use natural lighting to the maximum. Workrooms are evenly illuminated, regardless of the distance of the workplace from the windows. In general, comfortable working conditions are ensured, the system works seamlessly and at the same time saves energy - and this is the most important parameter: saving is not at the expense of quality.
If you are interested in calculating the cost of implementing such a system with you, or just have questions - write to ISavinkin@croc.ru or ask in the comments, I will be glad to answer.
At CROC, right at the office itself, the systems we are going to deliver to customers run in, so the field for the experiment was excellent.
For comparison, two floors were selected with identical placement of fixtures and the location of the working premises. Sensors of automatic lighting control were installed on one floor, and the lamps were replaced with energy efficient ones with increased efficiency. Power was turned off in rooms without people, plus the level of brightness of the light was reduced with sufficient daylight.
')
I'll show the result right away: in the end, we received a saving of 45% on a floor of just over 1,300 square meters. This is based on the human factor (selective shutdown of automation for your own comfort). Of course, the savings are not only due to the control of lighting, but also due to the replacement of lamps and the general modernization of lighting. Total, the payback period of the system, taking into account all the hardware and work - 5 years. The measurement was conducted from November 2, 2012 to March 30, 2013 (in the summer, with a larger light day, power will be needed even less, that is, the results will be better).
Diagram of the optimal mode of operation of artificial lighting in a typical room with windows (vertical - the intensity of the glow of lamps, horizontal - the clock).
Training
The seventh floor of our first office building (KROK-1) wanted to be changed while still designing the internal engineering systems of the KROK-2 building under construction. The point is that KROK-2 is conceived as an energy-efficient building and this requirement imposes a certain framework on the entire engineering infrastructure.
The task was simple: to provide high-quality and convenient lighting for office staff while minimizing the electrical power supplied. We decided to analyze on the basis of two floors of the first building. The test was the seventh. The sixth floor of KROK-1 with the existing traditional lighting system was chosen as the control one for the premises, squares and saturation with the employees. And there, and there we assembled accurate counters for detailed accounting.
On the seventh floor also:
- Changed control circuit lights.
- Standard switches were replaced with presence or motion sensors.
- New types of luminaires with high efficiency, lower power and the ability to smoothly adjust power were selected and installed.
Many Western manufacturers of lighting control equipment show rather seductive savings in their brochures. Sometimes these indicators of savings are checked in practice in Russian realities, sometimes not, sometimes they are written for ideal conditions without taking into account the “human factor” (more on this later). As a result, indicators from 20 to 50% of the decrease in energy consumption for lighting appear in different sources.
At first glance, what could be simpler than turning off or dim the light when it is not needed? The only question is how and who will determine when it is “necessary” and when it is not. We decided to try the solution from Esylux to control the lighting in a completely autonomous mode, evaluate the savings and, having our own expertise and experience, and then offer it to customers.
To begin with, we recalculated the number of luminaires and optimized their placement to provide the necessary illumination at work sites, taking into account the installation of new luminaires. It was important to take into account the characteristics of new lamps, plus to make the redistribution of groups of lamps to control depending on the light from the windows (put them parallel to the glazing line). Then it was necessary to mount sensors that automatically control the lighting depending on the presence of people, as well as having the function of controlling the intensity of the glow of the lamps depending on the conditions of natural light.
The preparatory part was like this - at workplaces, measurements were taken with the aid of a luxometer and checked against current regulations. It should be noted that to a greater extent these measurements were of an informative nature, and as a result, the lighting was adjusted to the wishes of the staff. For each particular workplace, adaptation according to the level of natural light was made according to measurements of illumination, according to the wishes of the employee (I’ll say this later) and according to the characteristics of the furniture in the room.
Presence sensors with dimming function (smooth power control) were selected as control elements.
New types of luminaires and their placement, taking into account the staff seating, allowed us to change for the better the picture of the distribution of illumination at all workplaces, reduce power consumption on the floor by about 40%, which ultimately affected the electricity consumption of the seventh floor as a whole compared to control sixth floor (about 45%).
Tests
The benefits of simply turning off the light and the typical sensor operation depending on the daylight can be seen in the image (the light is turned on only when people are in the room):
If we also apply dimming, we get the following picture (even greater savings, the brightness of artificial lighting is adjusted depending on the natural):
One of the indirect advantages was that everyone got used to it very quickly, that there is no need to use switches, the light is on, where it is needed, where there are people, and just as intensively as it is needed.
Among the drawbacks, it can be noted that in bright sunshine, some clouds and strong winds, it may turn out that the sensor constantly clicks the light, some employees are annoyed and it is necessary, at least for a while, to switch the system to semi-automatic mode. This can be attributed just to the “human factor” mentioned at the beginning: any system should not be done to the detriment of the convenience of the people using it, so ways are provided consciously to turn on the light for a long period of time by turning off the automatics. It is clear that this is done at the expense of savings.
The experiment was carried out on a lively working team (all participants in the experiment, thanks for your understanding and patience) and the conditions to which everyone had time to get used changed. In each particular case, the wishes of the employees themselves were taken into account: someone loves brighter, someone is darker, someone practically does not use general artificial lighting and is treated with a desk lamp. This also played a role in estimating savings: with standardized settings, for example, in a new building where no one ever worked, everyone would immediately get used to the new conditions and it can be assumed that the savings would be greater.
Technical part
In our case, sensors with an infrared sensitive element are used. Motion and presence sensors have the same principle of determining the presence, based on the difference in temperature of the human body and the environment.
I think everyone is familiar with these things - they are often found in hotels, for example.
In fact, the sensor responds to changes in the temperature of the observed space. At the “iron” level, this is realized with the help of a special lens, which consists of alternating transparent and opaque areas - as a result, it allows to divide the entire observed space into segments, at the border of which objects with a temperature different from the surrounding environment provide the response of the IR sensor . In this principle, one of the features of the sensors is hidden - they define the person worse when the sensor is moving on the sensor than the person walking along the tangent.
In the illustration below, a red person will be determined from a noticeably smaller distance than gray. The fact is that when moving to a sensor, a person can get into one sector and remain in it, despite the movement, until he overlaps the next one by increasing his “shadow” on the sensor. In the case of movement on a tangent, the person will cross the zones much faster and significant movements from sector to sector will be determined from a greater distance.
A feature of the sensors used is the ease of installation, even in an already mounted and working lighting system. Sensors are installed "in the gap" line and control the on-off using its own solid-state relay. The image shows the electrical circuit of switching on the sensor in line with the luminaire in case of control by a signal of 0..10V.
There are two main types of sensors:
- Motion sensors
- Presence sensors
The first is designed for periodic appearances of people, the second - for the constant presence of people and the measurement of the level of illumination.
At the same time, it is necessary to understand that both those and those sensors are formally determining movement, the names of “movement” and “presence” are used by the manufacturer for classification by application zones.
The main difference of motion sensors is in the algorithm for measuring illumination and control. They measure illumination only at the time of the first motion detection. For example, imagine a situation - the entrance to the shopping center, the lamp above it connected through this sensor, the sensor has a response threshold for example 250 lux and a shutdown delay of 2 minutes.
If a person enters the building early in the morning, when the sun has not yet risen and the level of natural lighting is less than 250 lux, the sensor detects the presence, measures the illumination, compares it with the threshold, closes the internal relay and turns on the lighting. If during the delay period of 2 minutes no one appears in the field of view, the light will turn off. If, in two minutes of delay, the next visitor has time to pass, the sensor will count two minutes from zero, without re-measuring the illumination. As a result, if the sensor does not measure the level of illumination, it may happen that the light does not turn off, despite the fact that the threshold has long been exceeded.
The presence sensors, in turn, measure the illumination constantly and compare it with the set value and are able to turn off the lights when the threshold is exceeded, even if the presence of people is detected
Motion sensors
We mounted them in the corridors and public areas. It turned out to be a good idea to turn them on in parallel, so that when a single light is triggered, the light will turn on throughout the corridor.
Compact presence sensors
Compact presence sensors are installed in the bathrooms and in the kitchen, the sensors have the same algorithm as the motion sensors in the corridors and public areas, but smaller sizes and coverage area.
Another problem was revealed in the bathroom - the person doesn’t run around the room very much (there is almost constant movement in the office premises, for example, moving the mouse), so the light can turn off unexpectedly. It is clear that in this case it will move, and the power will turn on, but, you see, it is not very comfortable. Therefore, we put up big shutdown delays for such sensors - from 15 minutes.
Presence sensors
In office areas and in elevator halls, we mounted presence sensors and switches. The switch can turn off the power to the sensor and the entire control group lighting.
When turned on, the sensor is automatically calibrated for 10-15 seconds, then the light turns off and the configured algorithm starts working:
- At a time when there are no people in the room, the light automatically turns off, the sensor works in the standby mode and the illumination test.
- When a person is detected, two options are possible:
a) There are people, but there is enough light from the windows - the sensor takes measurements and switches on the light when the light level falls.
b) The brightness of the illumination is chosen so as to reach the threshold established for the standard of illumination. People appeared - the light is turned on and adjusted to the level of the standard. - There are no people - the delay timer starts, if there are no changes, it switches off or goes to the 10% level of illumination.
Application
Our western colleagues install such systems in hotels (this is convenient for the guest and very practical), in offices, in manufacturing, in various public buildings, from city administrations to museums, and so on. Sometimes these things are put in houses.
In Europe, the main motive is “green technologies,” with us, I think, savings will play a big role.
From my own experience, we can say that the lighting control described in the above gives you the opportunity to forget about the switches and to use natural lighting to the maximum. Workrooms are evenly illuminated, regardless of the distance of the workplace from the windows. In general, comfortable working conditions are ensured, the system works seamlessly and at the same time saves energy - and this is the most important parameter: saving is not at the expense of quality.
If you are interested in calculating the cost of implementing such a system with you, or just have questions - write to ISavinkin@croc.ru or ask in the comments, I will be glad to answer.
Source: https://habr.com/ru/post/178425/
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