2.4. Optimising Daylight Dimming

2.4.1 Introduction and Use Case

When a Response sensor node decides about its appropriate light level, it can be configured to take into account the amount of ambient light in the surrounding environment. By reducing a luminaire’s light output in the presence of natural light, especially from those light fittings that are close to windows or skylights, energy savings can be increased, and occupancy comfort further improved.

Use Case: Lets assume that you have a floor plan with windows that can see natural light. You can caliberate and enable daylight dimming for the row of luminaires that can see natural light changes. Now assume that you have caliberated the daylight dimming where the Response sensor node has sensed it can achieve 350 lux level with 40% light output. During the course of the day,

If natural light contribute to the lux level that the Response sensor node can see directly and causes the ambient light to reach higher than 350 lux, the Response sensor node will dim the luminaire down until it can sense the same ambient light as it did at the time of caliberation.
If the amount of natural light reduces such that the ambient light level reduces below 350 the Response sensor node will automatically increase the light output level until it can achieve the same caliberated ambient light levels.

2.4.1.1 Operating Range

The daylight dimming is always limited for dimming up and down between the maxlight and lowlight values as configured on the Response sensor nodes. Which means when it is too bright it will dim the light output as low as 10% which is the default value.

Please note there is a hard limit in the system to force the nodes to not turn off even when the ambient light levels go beyond the calibrated value. It will go as low as 10% but will not turn off.

2.4.1.2 Recommendation

The daylight dimming calibration can be done in two ways.

Pick a time of day when there is a low to moderate amount of natural light in the environment to do the Daylight Dimming calibration. This is so the Response sensor node can take into account how natural light plays on the environment it is observing. Avoid calibrating for Daylight Dimming at night or when direct sunlight is entering the space as either of these scenarios may result in over or under-compensation by the lights. Dim the luminaires individually to achieve the desired light level.
Use a lux meter to caliberate the Response sensor nodes to the desired light level. Set the light meter on the appropriate illuminated surface. Note the lux level reading on the light meter. Dim the light level to reach the desired lux level. Each Response sensor node will calibrate based on its own, current environment. Adjust each of the Response sensor nodes individually to ensure all Response sensor nodes are satisfactorily calibrated.

2.4.2 How to Claiberate & Enable

Daylight Dimming is enabled using two sections in the app.

The light output menu &
The Daylight Dimming menu.

These menus are quite similar in both the IR and Response App. It is recommended that daylight dimming is enabled after the MaxLight has already been set, as the operating range is limited by the configured maxlight levels. The process for enabling Daylight Dimming is explained below;

Daylight Dimming Page

Light Output Page

2.4.3 Simple Steps

These are recommended steps for basic users who wish to quickly set up their individual luminaires for daylight dimming,

2.4.3.1 Response IR App

Login to the app and point your charged and working dongle towards your Response sensor node

Go to light output menu and start dimming your luminaire up/down to your intended light output
Switch to daylight dimming page from 3 bars on the top right corner
Click caliberate and enable.

Easy Steps IR App

2.4.3.2 Response App

Login to the app and the app will automatically try and select nearby nodes. Refresh until you can see the red dome of the selected Response sensor node

Go to light output menu and start dimming your luminaire up/down to your intended light output
Switch to daylight dimming page from 3 bars on the top right corner
Click caliberate and enable.

Easy Steps Response App

2.4.4 Detailed Configuration Steps (for advanced users)

It is recommended that if you are an advanced user responsible for configuring large project please see the detailed explanation of each step involved with daylight dimming configuration.

HOW TO CALIBRATE AND ENABLE DAYLIGHT DIMMING (Response IR App)
Response IR App commands	Response from node	Response from luminaire
Using the Dim+ and –Dim buttons of the Response IR App, adjust the light output of the target luminaires to the desired level* Note that this is not an adjustment to MaxLight, but a temporary dimming of the lights to a level that the Response sensor node can “calibrate” for Daylight Dimming.	Dome of node flashes red once to acknowledge receipt of each dimming command.	Light will increase in brightness by one dimming level (Dim+) or decrease in brightness by one dimming level (-Dim) for each button press.
Repeat the temporary dimming of all luminaires along the perimeter. Or use a light meter to achive a suitable dimming level. For advanced users that have to configure whole project you can zone the perimeter lights so that you can relay a similar configuration settings across all perimieter luminaires.	Dome of node flashes red once to acknowledge receipt of each dimming command.	Light will increase in brightness by one dimming level (Dim+) or decrease in brightness by one dimming level (-Dim) for each button press.
Switch to daylight dimming page & now point the dongle at the Response sensor node of the target luminaire and press the Calibrate & Enable button. Advanced users that have zoned the perimieter lights can relay this step for all perimeter lights in one go.	Node will blink red to acknowledge the receipt of configuration command When you relay the Response sensor node will acknowledge the calibration message by flashing its dome red and allow you 3 seconds to move out of the way before it takes a light reading and calibrates the Response sensor node for this level of light (as read by the ambient light sensor).	From this point onward, the luminaire will attempt to maintain the same level of light that was read by the ambient light sensor at the moment Daylight Dimming was calibrated.

*Desired level: We recommend using a light meter to sample bright and dark areas to verify that you are achieving recommended safe lux levels as the standard suggests for task being carried out in that space.

HOW TO CALIBRATE AND ENABLE DAYLIGHT DIMMING (OR Response App)
OR Response App commands	Response from node	Response from luminaire
Choose “Configure Nodes“ from the home screen once you login the app	None	None
Upon selection e.g. “Configure Nodes” OR Response App sends a 'Scan for Node ID' message in the background as you enter in “Light Output” menu and can see the “node selection“ with node address at the top.	Dome of node will turn solid red to acknowledge selection of the node.	None
If it is not the node you wished to select click on “Dismiss Node” or shake or pull-down refresh on your phone to select another node.	The node previously selected will settle its red dome to off and newly selected node will indicate it is selected by its red dome staying solid red.	None
Using the Dim+ and –Dim buttons of the Response App, adjust the light output of the target luminaires to the desired level. Alternatively use a light meter if necessary to achieve desired level*(explained above). Note that this is not an adjustment to MaxLight, but a temporary dimming of the lights to a level that the Response sensor node can “calibrate” for Daylight Dimming.	Dome of Response node flashes red once to acknowledge receipt of each dimming command.	Light will increase in brightness by one dimming level (Dim+) or decrease in brightness by one dimming level (-Dim) for each button press.
Repeat the temporary dimming of all perimeter luminaires to prepare them for a Daylight Dimming calibration. Advanced users can zone the perimieter lights as a first step. This will allow you to Relay a calibration signal across the entire zone at once. Or you can choose to calibrate each luminaire as you set their light outputs to reach desired/measured lux levels.	Dome of Response node flashes red once to acknowledge receipt of each dimming command.	Light will increase in brightness by one dimming level (Dim+) or decrease in brightness by one dimming level (-Dim) for each button press.
Once selected press the Calibrate & Enable button. If you have zoned all the perimeter luminaires this calibration process can be carried out for all of the lights in the zone by using the relay function. Note that the dim level of all of the luminaires in the zone must be set prior to this relay command being sent. In order to use relay, toggle the “Relay” option carefully as it will automatically relay the calibrate and enable option for each Response sensor node in the same zone with their current measured ambient light levels.	The node will acknowledge the calibration message by flashing its dome red and allow you 3 seconds to move out of the way before it takes a light reading and calibrates the Response sensor node for this level of light (as read by the ambient light sensor built-in the Response sensor node). Refer to start of this chapter to read more on relay	From this point onward, the luminaire will attempt to maintain the same level of illuminance that was read by the ambient light sensor at the moment Daylight Dimming was calibrated.
If you wish to query the daylight dimming status press the “query” button.	Dome of node flashes red once to acknowledge receipt of command	None

Once you have calibrated for Daylight Dimming, you can disable it and re-enable it if required, using the “Disable” and “Enable” buttons on the Response IR App and the OR Response App. If you are not happy with the caliberation you can re-caliberate the luminaires by following the above steps.

It is recommended to avoid enabling daylight dimming for the whole floor. If you have 100 luminaires on a floor and all have daylight dimming enabled for lets assume 3 rows closest to external windows. During the course of the day first row will adjust their light output in response to natural light that changes during the day. These changes of light output can trigger second row from window to adjust their light output and then the third row. However, as a result of this change the previously dimmed luminaires might not see as much ambient light as they were and hence will adjust again to reach the caliberated ambient light level. However, as a result of this new change on the first row the luminaires the luminaires in second and subsequently third row will adjust light output again. Hence you can imagine that the luminaire can end up dimming up and down due to the adjustment of other neighbouring luminaires while at the same time the actual natural light is also changing. Therefore the recommendation is benefit from daylight dimming on luminaires that are actually going to see natural light from external windows.