Indiscriminate specification of these products is no substitute for a well-designed lighting system based on customer needs and what is practical and affordable for them.
Luminaire-level lighting controls or integrated-controls luminaires are terms referring to LED luminaires that include integrated sensors and controllers. These products present an alternative to traditional wall or ceiling-mounted sensor installations. Integrated controls are possible because of both the rapid and continuing trend towards miniaturization and the standardization of interface and form factors, making it relatively straightforward to include these devices in a luminaire design.
Integrated-controls luminaires can be configured to operate as part of a stand-alone group that is not connected to a central panel or building control system. In this configuration, a local controller commands dim levels based on occupancy and daylight inputs from the sensors embedded in the group’s luminaires. This type of implementation reduces wiring and potentially eliminates the need for a central controller while also providing the individual-level control needed to comply with increasingly aggressive energy codes.
Luminaires can also be configured as part of a larger lighting control or building management system. In this configuration, the embedded controllers provide inputs directly to the overall system controller. This type of implementation provides for networking of luminaires or groups of luminaires for implementation of lighting schemes, and in the case of building management systems, a way to coordinate the response of other systems, most notably HVAC, with lighting response. Additionally, energy consumption data can be collected for monitoring and analysis purposes.
Most integrated-controls luminaires include, in addition to the LED source and driver, an occupancy sensor, a photosensor, control functionality and either wired or wireless connectivity. Other sensors may be incorporated as well, including temperature, humidity, etc. The control functions may be embedded in the driver or may be implemented in a separate component. A radio transmitter/receiver may be included for wireless connectivity. In addition, configuration software using a mobile app may be available for systems that feature a centralized network.
Luminaire manufacturers favor integrated-controls luminaire products as they streamline the manufacturing process and lower overall manufacturing cost. And integrated-controls luminaires are attractive in terms of facilitating building control systems that monitor and make decisions based on sensor inputs for code compliance and increased energy savings.
The primary energy codes adopted by states to varying degrees include the International Energy Conservation Code (IECC), the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, California Energy Commission (CEC) Title 24, Building Energy Efficiency Standards for Residential and Nonresidential Buildings, and Canada NECB (National Energy Code of Canada for Buildings). These codes all require, to varying degrees, implementation of occupancy sensing, dimming, and daylight response, with each new revision containing increasingly stringent requirements.
One of the main selling points for integrated-controls luminaires is the energy savings that can be achieved as compared to non-connected lighting. It is mainly due to potential energy savings that the US Department of Energy forecasts that connected LED lighting, a category which includes integrated-controls luminaires, is expected to increase to 30% of commercial installations by 2035.
(Source: US DoE Energy Savings Forecast of Solid-State Lighting in General Illumination, December 2019)
As an example, a study sponsored by the Northeast Energy Efficiency Alliance in 2020 sought to quantify the energy savings that could potentially be achieved. The study was conducted in a test environment that contained nine luminaires in a 27’ x 33’ space and concluded that the inclusion of controls resulted in a 50-74% energy savings over and above the savings achieved by LED lighting alone. Unsurprisingly, energy savings appeared to be correlated to the functional complexity of the implementation. As a caveat, a study conducted in a controlled environment may not be representative of results in real-world environments.
There are significant disadvantages related to integrated-controls luminaires as well. First, these products have a higher up-front cost with no firm return on investment, which depends upon the extent to which the product capabilities are implemented and the customer’s long-term use. Implementation of these capabilities also necessarily results in increased project complexity, a feature that often leads to customer frustration and misuse or disuse of the system. And last, not all customers need the sophisticated capabilities that integrated-controls luminaires provide. Indiscriminate specification of these products is no substitute for a well-designed lighting system based on customer needs and what is practical and affordable for them.
This article was originally published on EDN.
Yoelit Hiebert has worked in the field of LED lighting for over 10 years and has experience in both the manufacturing and end-user sides of the industry.