What is Daylight Harvesting?

What is daylight harvesting

You may have noticed that we have started to talk about ‘Daylight Harvesting’ in some of our more recent blog posts.

Whilst some of our readers may be very familiar with the term, we realise that there may be some who are not sure what ‘Daylight Harvesting” means, so we thought we should give an explanation.

In simple terms ‘Daylight Harvesting’ is a method of saving the energy costs associated with lighting.

Over the last few years we have seen several new technologies become available, which have dramatically reduced the energy consumption of lighting systems. The most significant being the introduction of LED lighting.

However, it was soon realised that the best way to save energy is to only use it when you must.

Historically, office buildings and workplaces had light systems installed, which were switched on for the entire time that the building was occupied. Even if there was plenty of sunlight coming in through the windows.

Daylight Harvesting makes use of the available sunlight.

Daylight sensors are incorporated into the lighting system, which can detect daylight. Manufacturers, such as Hytronik have developed sophisticated sensors, which can differentiate daylight from light generated by a LED source.

As the level of sunlight rises and falls throughout the day, the output level of the LED lighting system is adjusted accordingly. A further level of intelligence is incorporated so that the daylight sensors only activate the LED lighting if someone is in the room, or work area.

Daylight harvesting. Light does not activate because there is enough sunlight.

Fig 1:

Sensor detects someone has entered the room and there is plenty of sunlight. Lighting is not activated.


Daylight harvesting. Light activates because there is not enough sunlight.

Fig 2:

Sensor detects someone has entered the room and there is not enough sunlight. Lighting is activated.


Daylight harvesting. Light is adjusted according to the available sunlight.

Fig 3:

The work space is occupied. As the sunlight rises and falls throughout the day, the level of artificial lighting is adjusted accordingly.


More advanced systems incorporate tuneable white LED drivers so that the colour temperature can also be altered throughout the day to create a more natural lighting experience, which is in tune with our circadian rhythms.

Research has shown that the colour temperature of light can affect our level of productivity at work.

At first, the idea of incorporating 'Daylight Harvesting' into an LED lighting system may seen daunting. However, ADM’s expert team is on hand to guide you through the range of Hytronik products. Simply call our office on 1300 236 467.

You will most likely be pleasantly surprised at how simple the solution is. The beauty of a Hytronik solution is that is compatible with most MEAN WELL LED drivers.

Simple Method to Adding Daylight Harvesting to Your Lighting Installation

The Hytronik DS02 daylight sensor gives you a very easy solution to adding a ‘daylight harvesting’ function to any LED driver, which has a 1-10V dimming function. This includes many of MEAN WELL’s dimmable LED drivers.

Hytronik DS02

The DS02 daylight sensor is simply wired to the dimming terminals, or wires on your LED driver in place of the dimming controller.

Hytronik DS02 Wiring Diagram

The DS02 will then vary the output of the LED driver between 10 ~ 100% according to the level of natural light available.

Daylight harvesting sensor function diagram

There is a built-in potentiometer so that you can set the required brightness level.

The daylight sensor reads and measures the available natural daylight against the target value, calculating how much artificial light is needed.

This demand is then converted to a 1-10V signal and fed to the LED driver, which will then set the LED driver to the appropriate output level.

It’s that simple.

How to Capture Daylight and Augment Natural Light for Productivity in the Workplace

These days we have a much clearer understanding of how light can influence an individual’s well-being and productivity.

Employers are now looking at harvesting the available daylight to provide a more productive work environment, which also has the advantage of reducing energy costs.

Your initial thought maybe that such a lighting solution is going to be very expensive. But this may not necessarily be the case, especially if you already have LED lighting installed with dimmable LED drivers.

ADM already stocks a range of Daylight Harvesting sensors, which are compatible with many dimmable LED drivers, including MEAN WELL LED divers.


Within our range of Daylight Harvesting sensors are models that can be retrofitted to existing installations and models and there are a wide range of different mounting options available.

How do Daylight Harvesting Sensors work?

The sensor continually monitors the amount of natural daylight in the room, or work area. Hytronik’s Daylight Harvesting sensors feature an Intelligent Photocell, which can determine the difference between natural light and the light emitted from a LED light fitting.

When the sensor detects ample natural daylight is available it will not activate the LED lights, even if it detects people moving into the area it is sensing.

Daylight harvesting. Light does not activate because there is enough sunlight.


Should the level of natural light fall below a level that is sufficient, then the LED lighting is switched on. This only occurs if motion is detected in the work area.

Daylight harvesting. Light activates because there is not enough sunlight.


The dimming level of the LED lights is regulated according to the amount of natural daylight available, thereby reducing energy costs.

Daylight harvesting. Light is adjusted according to the available sunlight.


The sensors can be programmed to dim to a stand-by dimming level after a pre-determined hold time has elapsed. The sensor can also be dimmed to turn the LED lights off according to a pre-set stand-by time has elapsed. Combined, these features ensure work place safety, by ensuring no one has been plunged into darkness, because they have been sitting still for a long period of time.

Sensors are available with localised programming, usually via a rotary switch, or via a remote control.

Hytronik Rotary Switch
Hytronik HRC-09


The remote-control option is great if you have a larger work area with multiple sensors, which you want to program quickly. The sensors retain the last programme entered regardless of the method used. So, if there is a power interruption, the lighting system will continue to function as intended once the power has been restored.

If no motion detection is required in your application then the Hytronik DS02 Daylight Harvesting sensor would be a more economical solution.


Human Centric Lighting Control

It has been relatively well understood for some time now that light influences our biological responses.

Lighting designers have turned their attention to creating ‘Human Centric’ lighting to promote a healthy and productive environment to both live and work in.

ADM stocks a range of Human Centric lighting control devices from Hytronik and offers technical support to lighting designers creating human centric lighting systems.


Our stock range includes daylight harvesting sensors, tunable white LED drivers and control modules.

To make life easy for the lighting designer, Hytronik has developed a simple de-centralised human centric lighting solution with a tuneable white feature.

You can download an overview of the solution by clicking on the link below:

Hytronic Human Centric Circadian Rhythm Human Centric Lighting Solution.pdf

Why Human Centric Lighting Control?

Light plays a significant role in affecting our circadian rhythms and our wellbeing.

The 2017 Nobel Prize in Physiology or Medicine was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young. This was in recognition of their discoveries of molecular mechanisms controlling the circadian rhythm.

What this report demonstrates is that circadian rhythms are certainly no myth and light does play a key role in how our body clocks work.

Therefore, it is fair to say that artificial lighting systems can influence how we feel throughout the day and better designed lighting systems can improve our well-being and productivity.

LED lighting has been criticised by some for providing an unhealthy environment.

However, the fact that LED light is far more controllable than traditional lighting methods, means that there is a solution. After all, it was impossible to control the colour temperature of a fluorescent tube, let alone dim it. Office spaces were just flooded with unnatural light, usually switched on when the first person walked into the office and not turned off until the last person left.

The introduction of smart lighting control solutions, such as those from Hytronik, enable lighting designers to create an environment that makes the best use of the available ambient daylight, turning LED lights on and off as required and adjusting the light levels and colour temperature to mimic as closely as possible the natural light we would normally experience. 

Of course, these solutions also have the highly desired side effect of reducing energy costs and any pollution associated with generating the electricity required to power the lights.

Product Review: Hytronik HIM32 & HIM34 Daylight Harvesting Sensors

The Hytronik HIM32 and Hytronik HIM34 are combined motion / daylight harvesting sensors, which have been designed for use with high-bay lights in retrofit applications and new installations.

Hytronik HIM32
Hytronik HIM34


Both have exactly the same features, the only difference being that the HIM32 controls 1-10V dimmable LED drivers and the HIM34 controls DALI dimmable LED drivers.

Key Features

Daylight Harvesting allows you to optimise the available daylight in the workspace. As well as using the sensor to switch lights on and off as needed, or it can be configured to dim to a pre-set level after a set period of no motion being detected.

These sensors incorporate both PIR and microwave motion detection. Both technologies offer have their own advantages and the sensors can be set to respond either when both are activated, or when either one or the other is activated.

This means one model of sensor can be used for many different applications.

Advantages of Microwave Motion Sensing

  • Sensitive to minimal movement
  • Sensitive to radial movement
  • Can be reflected by objects, allowing you to cover a large area
  • Resilient to heat sources, smoke detectors and air conditioners

Disadvantages of Microwave Motion Sensing

  • Penetrates walls, can pick up motion on the other side of a wall
  • Can be falsely triggered by motion behind the sensor
  • Can be triggered by fans, water pipes and lifts

Advantages of PIR Motion Sensing

  • Does not penetrate solid surfaces, so ideal for a contained area
  • Sensitive to tangential movement
  • Does not activate to motion from a ‘non-heat’ source

Disadvantages of PIR Motion Sensing

  • Can be triggered by a heat source

Configuring the HIM32 and HIM34 Sensors

There are two methods for configuring the HIM32 and HIM34 sensors.

Rotary Switch

A single rotary switch gives you 16 different pre-programmed control sequences. These offer you a combination of different hold times, daylight sensitivity, standby times and standby light levels.

Remote Control

Using the Hytronik HRC-11 remote control you can configure the following parameters:

  • Lux level
  • Hold Time
  • Standby Time
  • Standby Dimming Level
  • Motion Detection Range

Hytronik HRC-11 Remote Control

The HRC-11 is well worth the investment as it obviates the need for a scissor lift to get up to the ceiling space to adjust these parameters, greatly reducing installation costs and improving employee safety.

Mounting Options

There are three different mounting options available:

  • Surface Mount

Surface / Ceiling Mount Daylight Harvesting Sensor

  • Conduit Mount

Conduit Mount Daylight Harvesting Sensor

  • Clamp Mount

Clamp Mount Daylight Harvesting Sensor

These different options give you maximum installation flexibility. 

The Clamp Mount fixing is preferred by most installers as the fixing enables the sensor to be mounted directly to the luminaire without the need for drilling holes and screwing down.  It also incorporates a hinge to adjust to the best detection orientation.

Lens Options

Each sensor is supplied with three lenses:

  • Round
  • Across Aisle
  • Along Aisle

These provide a different detection area for the PIR sensor, so that you can optimise the performance of the sensor according to the application at hand.

Price and Availability

ADM carries stock of both the HIM32 and HIM34. These daylight harvesting sensors are remarkably cost effective.

Hytronik Daylight Harvesting Solution

Daylight harvesting systems reduce energy consumption by using the natural daylight that is available to offset the use of artificial lighting. This is made possible by the implementation of smart lighting control systems, which can dim or switch electric lighting in response to the changing availability of daylight.

Hytronik has several products that are perfect for daylight harvesting applications. For example, the feature rich Hytronik HC419VRC/DH daylight harvesting sensor/controller and standalone Hytronik HMW22 microwave motion sensor.

The HC419VRC/DH has integrated photocells, which means you don’t need to drill and install one in the luminaire body.



The daylight sensor measures the ambient light level and calculates the amount of artificial light that is required to reach the target area. If natural light is insufficient the sensor passes the required dimming level to the driver via a 0- 10V signal to correctly illuminate the area for optimum comfort. The HC419VRC/DH’s 0-10V dimming control output make it compatible with MEAN WELL LED drivers.

For energy efficiency, the HC419VRC/DH includes a motion sensor to dim and turn off the lights after preset hold times if no occupancy is detected. Up to 10 HC419VRC/DH’s can be connected as a group and if one senses motion when artificial lighting is required, then all sensors are triggered to illuminate a whole area for convenience.

Programming of the HC419VRC/DH is easily done with 1-key commissioning HRC-11 remote control, which simplifies setting scenes, detection range, daylight threshold, ambient daylight threshold, hold-time, standby time, etc.

The standalone HMW22 is a flush mount microwave motion sensor also with built-in daylight harvesting capability. Programming of the above parameters is likewise done with the HRC-11 remote control or by selection of 16 preset settings of a rotary switch.

Hytronik HMW22

The following illustration shows when there is sufficient natural light the lights are off despite presence being detected.

Daylight harvesting solution

When there is insufficient natural light the sensor regulates the dimming intensity to maintain a defined lux level on the target area. The lighting is dimmed and turned off after hold time and standby periods to save energy.

Daylight harvesting product key features are:

  • Microwave and PIR occupancy detection
  • User friendly remote control handset parameter setting
  • Integrated or separated occupancy and daylight sensors
  • Selectable constant current output settings
  • Ambient light detection and calculation of required artificial light
  • Programmable hold time, standby time and standby light level

For further information on Daylight Harvesting, please call ADM Systems on 1300 236 467.


23 November 2020