Lighting controls: Best practices begins with a strategy
ASHRAE Standard 90.1 requires lighting professionals to include power allowances, daylighting controls, functional testing, and submittals in their lighting designs. This discussion includes an overview of lighting control options along with best practices for lighting designers and electrical engineers in working with their clients.
- Learn how to create a lighting control strategy through client inquiry.
- Identify best practices for lighting designers to work with clients in making smart lighting decisions.
- Identify how human factors impact lighting outcomes and energy strategies.
Lighting controls, coupled with lamp technology, have evolved toward more automated design and away from reliance on human intervention with the goal of saving energy. This automated approach contributes to a net zero or near net zero building design by adjusting the artificial lighting output to ensure the room is not overlit.
A critical part of successful energy-saving lighting control design is occupant education—making sure the occupants understand how their lights are controlled and how they can best use the designed system. This also may include recommendations for users to schedule regular adjustments to the light output over the life of the lamp, allowing for less use when new lights are more intense, and increasing light output as lamps lose intensity toward the end of life, thus saving energy and money.
Best lighting control practices begin with determining a lighting control strategy. Almost all states have adopted an energy code, with the primary code used being equivalent to ASHRAE Standard 90.1-2007 or International Energy Conservation Code (IECC) 2009. Many more states are moving toward adoption of ASHRAE Standard 90.1-2013 or IECC 2012.
Although there are specific codes and standards, many options fit within those guidelines. The following five questions can assist in the decision-making process for clients and engineers:
- How will the facility be used? The type of facility and how it will be used will determine a general direction for the lighting controls. For example, a 24/7 mission critical facility such as a hospital, correctional facility, or data center will have different functional requirements and goals than a general office building or an educational facility. So, levels of importance for lighting controls will vary between the type of facility as well as the individual spaces within each facility. For example, a large cafeteria space requires different controls than a corridor or classroom.
- What are the client’s energy goals? The facility owner’s energy goals and municipal code directives will mandate specific lighting control requirements that, in turn, will inform potential decisions with respect to a lighting control strategy, whether it is a new facility or an existing facility. Such considerations may include meeting a net zero challenge, a Watt/sq ft requirement, facility owner standard or preference, energy rebates requirements, and cost of installation and maintenance.
- What type of user will operate the facility? The level of complexity of a system, as well as the sophistication level of the users, can determine if a central lighting control system is affordable and preferred, or if individual spaces will be controlled independent of one another. If an end user does not have a tech-savvy facility management team, it might be in its best interests to keep the system as simple as possible with individual room controls, such as stand-alone occupancy sensors and manual switches for daylight controls.
- What are the safety and emergency requirements? Lighting controls that consider maintaining safety during power outages while saving energy is another consideration. In these instances, an emergency relay device is required to turn on controlled lighting during an outage to comply with codes and standards. This inherently incorporates emergency egress lighting into the lighting control scheme. With corridor lighting controlled by a relay panel, low-voltage switches can be locked out when the building is occupied, which prevents required egress lighting from being shut off inadvertently. If the facility is used after-hours, the switch could function normally, allowing corridor lighting to be manually turned on and off as needed.
- Are safety and budget issues in balance? Sometimes, the drive to save energy eliminates night-lighting strategies to illuminate the interior of buildings for security purposes. Night-lighting is often used to deter vandalism or breaking into and entering a building. Occupancy sensors can aid in this aspect by turning lights on when someone is moving through the building, inherently incorporating night-lighting into the lighting control scheme.