Kevin Willmorth on Installing Controls in Existing Buildings

Guest article by Kevin Willmorth, Lumenique

The need for controls and advantages of integrating controls into lighting systems is not diminished by any preexisting condition of a building, new or existing. In many cases, integrating controls into existing facilities may be a more effective path toward energy savings than a complete lighting refit. This is particularly true for facilities that have already invested in replacement lamp retrofitting, leaving minimal room for efficacy improvement for justifying further fixture replacements. Controls can easily magnify any other savings realized.

While installing controls in new construction or full-scale remodeling is reasonably straightforward, retrofitting controls into an existing building or space can be somewhat problematic, especially when cutting into walls and ceilings is undesirable. To this end, the first step in assessing an appropriate approach is to establish what the goals of a retrofit are. Pure energy savings gains can be realized with simple ON-OFF controls additions, while inclusion of dimming functionality requires greater investment. Embracing more complex targets, such as inclusion of human factors driven lighting strategies are even more involved.

For simple energy savings, the first line of attack is to install occupancy sensors and/or daylight sensors in series with manual controls that already exist. In closed spaces, such as restrooms, small single-occupant office spaces, back of house corridors and stairwells, storage spaces, or other enclosed occupancies, the addition of wall box occupancy controls are ready additions. For spaces where the existing wall control does not facilitate wall box controls, such as stairwells, or other spaces where the wall mounted device would not have the visibility required for proper operation, installing ceiling mounted control devices are the next available option. Generally, the addition of one or more ceiling-mounted controls is accomplished by locating the control near an existing fixture to facilitate simple wiring connections.

Another option for addressing simple on-off functionality is the use of self-powered wireless controls, such as those offered by EnOcean Alliance members. Occupancy and light sensors are simply installed where they have the best functional view of the space, with no wiring required. Receiver controls, acting as relays, are then installed to respond to the sensor instructions. Receivers can be located inside fixtures, at a lighting panel, inside an existing switch box, or added to a lighting circuit to control a series of luminaires. The added expense of these components is justified by the reduced requirement for re-wiring.

Power-line communications is another option for ON-OFF control functionality. Using the building’s power lines as a communication pathway, manual controls can be placed in existing switch locations, adding control over multiple control addresses. Adding relay/receivers into fixtures, or fixture circuits are then programmed to respond to switch controls, or other relays, which can include photosensors and occupancy sensors.

Self-powered controls can also be used for basic step-dimming operation, when there is a need for changing illumination levels from a wall control. Dimming can also be accomplished using standard wall box controls, assuming the lamps and/or luminaires employed are dimming capable. For this purpose, the simplest dimming strategy is to utilize phase cut dimmers with appropriate lamps, ballasts, drivers, and/or fixture retrofits. This utilizes existing wire connections, with minimal additional electrical work required. However, the variability of performance between dimmers and light sources may produce undesirable results, such as flicker, truncated dimmer function, low level cut off, or other effects. Before any such retrofit strategy is pursued, it is recommended that samples of the light sources and dimmers be tested for compatibility. Power-line controls can also be used for dimming function, with the same compatibility concerns as wall box dimmers. Where some access is possible, retrofitting 0-10V controls is another viable option, requiring only the routing of low-voltage control wires and replacement of drivers or ballasts to 0-10V capable components.

If the requirement is for automatic, sensor-activated dimming, neither phase-cut dimmers or power-line controllers are available for that purpose. For this, the options available for integrating automatic control response to daylighting with dimming function requires greater investment.

The most versatile, minimally intrusive approach to integrating dimming and ON-OFF control into existing facilities is through wireless control technology. Wireless modules can be added to luminaires, and cut into circuits, while control stations are readily retrofitted into existing switch box locations. Further, wireless controls can also be activated by programming and respond to self-powered sensors.

For wireless control installations, there are two primary options. Bluetooth control, which operates within a limited range, pairing operation to a controller or smart device (phone or tablet), offers reliable performance with no need for additional routers or other networking devices. Retrofit lamps are now available that are controlled by Bluetooth connection to devices using apps available. For larger commercial scale installations, Douglas Lighting Controls offers a Bluetooth solution that includes ON-OFF control, bi-level functionality, and sensor response features with no network or on-site internet connectivity required.

For larger facilities, commercial wireless components can deliver every function of wired controls connections, with minimal intrusion on existing wiring or building surfaces. The range of options is growing rapidly, as demand for controls integration has grown. True WiFi connected lighting controls require some form of bridge or hub that acts as the interpreting connection between controllers and controlled devices. At the low end of the scale are products designed primarily for residential installations, that can be used for light commercial, small retail, and similar applications. These offer a range of automatic controls functions, including sensors, but have one serious failing. The reliance on Internet based communications, through which the hub communicates and translates instructions, can produce reliability issues that larger commercial users are not likely to tolerate.

A true commercial wireless control product using WiFi connectivity or Bluetooth communications protocols will not depend on Internet connection to operate. The Lutron Vive Wireless Control system is a good example of a wireless control platform for commercial application. The system includes daylight and occupancy sensors, wall and smart device control, it also includes the capability of controlling 0-10V dimmable drivers and ballasts. Further, with advanced control functionality, the Vive system can be configured and operated in compliance with virtually all current energy codes, including those requiring multi-level response to sensor input. These features, offered by other wireless controls producers, are what separate residential scale controls from commercial grade products.

Retrofitting of controls has become easier with the advent of wireless technologies. However, that does not mean that installing such systems is as simple as plug-n-play. To be assured of proper function and successful installation requires careful product selection, which includes testing controllers and controlled loads to be assured of compatibility. Beyond this, the advantages of adding controls to reduce energy use, redress light levels, or reduce operational expenses are well worth considering.