5.4 Mandatory Lighting Controls

This section contains information about lighting controls that must be installed, regardless of the method used to comply with the lighting power requirements.

All lighting controls and equipment must comply with the applicable requirements in §110.9, and must be installed in accordance with the manufacturer's instructions (§130.0(d)).

Mandatory nonresidential indoor lighting controls include the following:

1.    Area Controls. Manual controls separately controlling lighting in each area.

2.    Multi-Level Controls. Providing occupants with the ability to use all of the light, some of the light, or none of the light in an area.

3.    Shutoff Controls. Automatically shutting off or reducing light output of lighting when the space is vacant.

4.    Automatic Daylighting Controls. Separately controlling some or all of the lights in the daylight area from the lights that are not in the daylight area.

5.    Demand Responsive Lighting Controls. Installing controls that are capable of receiving and automatically responding to a demand response signal.

5.4.1    Area Lighting Controls

All luminaires in each area enclosed by ceiling-height partitions shall be independently controlled from luminaires in other areas, with fully functional manual ON and OFF lighting controls.

EXCEPTION: The exception to the mandatory area lighting control requirements is that up to 0.2 watts per square foot of lighting in any area within a building may be continuously illuminated during occupied times to allow for means of egress, provided that the following conditions are met:

1.    The area is designated for means of egress on the building plans and specifications submitted to the enforcement agency under §10-103(a)2 of Part 1.

2.    The controls for the egress lighting are not accessible to unauthorized personnel.

5.4.1.1     Requirements for ON and OFF Controls

The ON and OFF lighting controls shall meet the following requirements:

1.    Be readily accessible to occupants; and

2.    Be operated with a manual control that is located in the same room or area with the lighting that is being controlled by that lighting control.

EXCEPTIONS: There are two exceptions to the requirements for these controls to be readily accessible and located in the same room:

1.   In malls and atria, auditorium areas, retail merchandise sales areas, wholesale showroom areas, commercial and industrial storage areas, general commercial and industrial work areas, convention centers, and arenas, the lighting control shall be located so that a person using the lighting control can see the lights or area controlled by that lighting control, or so that the area being lit is annunciated.

Annunciated is defined in the §100.1 as a type of visual signaling device that indicates the on, off, or other status of a load.

2.   Public restrooms having two or more stalls, parking areas, stairwells, and corridors may use a manual control that is not accessible to unauthorized personnel. However, note that all other lighting controls in accordance with §130.1 are still required.

5.4.1.2     Interaction of Manual ON and OFF Controls with Other Lighting Controls

'In 'addition to the manual area lighting controls, other lighting controls may be installed provided they do not override the functionality of controls installed in accordance with §130.1(a)1 (functionally controlled with a manual ON and OFF lighting control), §130.1(a)2 (readily accessible), or §130.1(a)4 (separately controlled lighting systems).

5.4.1.3     Separately Controlled Lighting System

'In addition to the requirements in §130.1(a)1, 2, and 3:

1.    General lighting shall be separately controlled from all other lighting systems in an area.

2.    Floor and wall display, window display, case display, ornamental, and special effects lighting shall each be separately controlled on circuits that are 20 amps or less.

3.    When track lighting is used, general, display, ornamental, and special effects lighting shall each be separately controlled.

5.4.2    Multi-Level Lighting Controls

The multi-level lighting control requirements allow a room to be occupied with all of the lights turned on, part of the lights turned on, and none of the lights turned on, whether the room is occupied or vacant. The number of required lighting control steps varies, depending on the type of lighting technology in each installed luminaire, in accordance with Table 5-1 (Table 130.1-A of the Energy Standards). The uniformity requirements in Table 5-1 require that multi-level control occur per luminaire so one cannot meet this requirement by controlling alternate luminaires or alternate rows of luminaires. Note that switching alternate lamps in each luminaire for certain luminaire types, is permitted per Table 5-1 for meeting the illuminance uniformity requirement.

This requirement applies to enclosed spaces larger than 100 square feet and with a connected general lighting load greater than 0.5 W/ square foot. General lighting does not include task lights, display, or ornamental lighting.

These spaces also must comply with the following:

1.  Lighting shall have the required number of control steps and meet the uniformity requirements in accordance with Table 130.1-A.

2.  Multi-level lighting controls shall not override the functionally of other lighting controls required for compliance with §130.1(a) area controls, (c) automatic shut-off controls (d) daylighting controls. and (e) demand responsive controls.

Dimmable luminaires shall be controlled by a dimmer control that is capable of controlling lighting through all required lighting control steps and that allows the manual ON and OFF functionality required by §130.1(a).

5.4.2.1     Exceptions to multi-level lighting controls

The following applications are not required to comply with the requirements in Table 130.1-A of the Energy Standards (Table 5-1).

1.    Classrooms with a connected general lighting load of 0.7 watts per square feet or less and public restrooms shall have at least one control step between 30-70 percent of full rated power.

2.    An area enclosed by ceiling height partitions that has only one luminaire with no more than two lamps.

3.    Areas specified in §130.1(b). These areas include:

•    Aisle ways and open areas in warehouses

•    Library book stack aisles 10 feet or longer that are accessible from only one end and library book stack aisles 20 feet or longer that are accessible from both ends

•    Corridors and stairwells

•    Parking garages, parking areas, and loading and unloading areas

4.    The area specified in §130.1(c)6 and 7 are also not required to meet the requirements of §130.1(b).

Table 5-1: Multi-Level Lighting Controls and Uniformity Requirements

Table 130.1-A of the Energy Standards

5.4.3    Automatic Shut-OFF Controls

'In 'addition to lighting controls installed to comply with §130.1(a) (manual ON and OFF controls located in each area); §130.1(b) (multi-level lighting controls); §130.1(d)(automatic daylighting controls); and §130.1(e) (demand responsive controls) - all installed indoor lighting shall be equipped with shut-OFF controls that meet the following requirements (§130.1(c)1):

A.   Shall be controlled with one or more of the following automatic shut-OFF controls:

1.    Occupant sensing control.

2.    Automatic time-switch control

3.    Other control capable of automatically shutting OFF all of the lights when the space is typically unoccupied.

B.  Separate controls for lighting on each floor, other than lighting in stairwells.

C. Separate controls for lighting in each room (enclosed space); spaces larger than 5,000 square feet will have more than one separately controlled zone where each zone does not exceed 5,000 square feet.

EXCEPTION: Only in the following function areas, the separately controlled space may exceed 5,000 square feet, but may not exceed 20,000 square feet per separately controlled space, and separately controls the lighting on each floor:

a.    Mall

b.    Auditorium

c.    Single tenant retail

d.    Industrial

e.    Convention center

f.     Arena

D.   Separate controls for general, display, ornamental, and display case lighting.

5.4.3.1     General Exceptions to §130.1(c)1:

The following applications are exempted from the automatic shut-OFF requirements of §130.1(c)1:

1.  Where the lighting is serving an area that is in continuous use, 24 hours per day/365 days per year.

2.  Lighting complying with §130.1(c)5 instead of §130.1(c)1. This exception applies to those areas where occupant sensing controls are required to shut OFF all lighting. These areas include offices 250 square feet or smaller, multipurpose rooms of less than 1,000 square feet, classrooms of any size, or conference rooms of any size, in accordance with §130.1(c)5.

3.  Lighting complying with §130.1(c)6 in addition to §130.1(c)1. This exception applies only to those areas where full or partial OFF occupant sensing controls are required in addition to the requirements in §130.1(c)1. These areas include aisle ways and open areas in warehouses, library book stack aisles 10 feet or longer that are accessible from only one end, library book stack aisles 20 feet or longer that are accessible from both ends, and corridors and stairwells (§130.1(c)6).

4.  Lighting complying with §130.1(c)7 instead of §130.1(c)1. This exception applies to those areas where partial OFF occupant sensing controls are required. These areas include stairwells and common area corridors that provide access to guestrooms and dwelling units, in accordance with §130.1(c)7A; or parking garages, parking areas and loading and unloading areas, in accordance with §130.1(c)7B.

5.  Up to 0.1 watts per square foot of lighting may be continuously illuminated, provided that the area is designated for means of egress on the plans and specifications submitted to the enforcement agency under §10-103(a)2 of Part 1.

Note that the above exception is a change from the previous code version. All building types are permitted up to 0.1 watts per square foot for egress lighting.

6.  Electrical equipment rooms subject to Article 110.26(D) of the California Electric Code.

7.  Lighting that is designated as emergency lighting, connected to an emergency power source or battery supply, and is intended to function in emergency mode only when normal power is absent.

5.4.3.2     Use of Countdown Timer Switches

Countdown timer switches shall not be used to comply with the automatic shut-OFF control requirements in §130.1(c)1.

EXCEPTIONS: Only the following three function areas may use a countdown timer switch to comply with the automatic shut-OFF control requirements:

1.    Single-stall bathrooms smaller than 70 square feet may use countdown timer switches with a maximum setting capability of ten minutes.

2.    Closets smaller than 70 square feet may use countdown timer switches with a maximum setting capability of ten minutes.

3.    Lighting in a Server Aisle in a Server Room may use countdown timer switches with a maximum setting capability of 30 minutes.

a.    A Server Aisle is defined by §100.1 as an aisle of racks of Information Technology (IT) server equipment in a Server Room. While networking equipment may also be housed on these racks, it is largely a room to manage server equipment.

b.    A Server Room is defined by §100.1 as a room smaller than 500 square feet, within a larger building, in which networking equipment and Information Technology (IT) server equipment is housed, and a minimum of five IT severs are installed in frame racks.

5.4.3.3     Requirements for Automatic Time Switch Control

A.   Override Lighting Controls

When an occupant sensing control is used to comply with the automatic shut-OFF requirements, lighting is automatically controlled in response to the presence or absence of occupants. However, when an automatic time-switch control is used to comply with the automatic shut-OFF requirements, such a control is not responsive to the presence or absence of occupants. Therefore, when any control other than an occupant sensing control is used (i.e.: automatic time-switch control, signal from another building system, or other control capable of automatically shutting OFF all of the lights), the lighting control system shall incorporate an override lighting control that:

1.    Complies with §130.1(a) (Manual ON/OFF control located in each room).

2.    Allows the lighting to remain ON for no more than 2 hours when an override is initiated.

EXCEPTIONS: In the following function areas, if a captive-key override is utilized, the override time may exceed 2 hours:

a.    Malls

b.    Auditoriums

c.    Single tenant retail

d.    Industrial

e.    Arenas.

B.   Holiday “Shut-OFF” Feature

If an automatic time-switch controls installed to comply with §130.1(c)1, it shall incorporate an automatic holiday "shut-OFF" feature that turns OFF all loads for at least 24 hours, and then resumes the normally scheduled operation.

EXCEPTIONS: In only the following function areas, the automatic time-switch control is not required to incorporate an automatic holiday shut-OFF feature:

a.    Retail stores and associated malls

b.    Restaurants

c.    Grocery stores

d.    Churches

e.    Theaters

5.4.3.4     Areas where Occupant Sensing Controls are required to shut OFF ALL Lighting

Lighting in the following function areas shall be controlled with occupant sensing controls to automatically shut OFF all of the lighting when the room is unoccupied. 'In 'addition, controls shall be provided that allow the lights to be manually shut-OFF in accordance with §130.1(a) regardless of the sensor status:

a.    Offices 250 square feet or smaller

b.    Multipurpose rooms of less than 1,000 square feet

c.    Classrooms of any size

d.    Conference rooms of any size

In areas required by §130.1(b) to have multi-level lighting controls, the occupant sensing controls shall function either as a:

a.  Partial-ON Occupant Sensor capable of automatically activating between 50-70 percent of controlled lighting power.

b.  Vacancy Sensor that automatically turns lights OFF after an area is vacated of occupants but requires lights to be turned ON manually.

In areas not required by §130.1(b) to have multi-level lighting controls, the occupant sensing controls may function as either as a:

a.  Normal occupant sensor.

b.  Partial-ON occupancy sensor.

c.  Vacancy sensor.

Note that multipurpose rooms less than 1,000 square feet, classrooms greater than 750  square feet and conference rooms greater than 750 square feet, are required to be equipped with an occupancy sensor that controls the HVAC thermostat setup and setback and ventilation. (§120.2(e)3) As a result, the occupancy sensor or lighting control system in the space must be capable of triggering the HVAC without fully triggering the lighting load.

The same occupancy sensor used to control the lighting can also control the HVAC system. Besides the cost benefit, the benefit of using the lighting occupancy sensor to control the HVAC unit is that it is immediately apparent that the occupancy sensor has failed when it is controlling the lighting and it may be less apparent that the sensor has failed if it is controlling only the HVAC system.

This method of controlling cooling, ventilation and lighting satisfies the requirements of §120.2(e)3 and §130.1(c), so no additional shutoff controls are required in these spaces, except in cases of lighting associated with the egress path, which may remain energized until the building is scheduled to normally be unoccupied.

5.4.3.5     Areas where full or partial OFF occupant sensing controls are required 'in addition to complying with §130.1(c)1

In addition to the basic shutoff requirements in §130.1(c)1, §130.1(c)6 requires a shutoff device (typically a timeswitch) for the lighting system, which may be done in a building-wide manner. Lighting in the listed spaces (warehouses, library book stack aisles, and stairwells and corridors) must have the capability to reduce lighting power by at least 50 percent when they are unoccupied.

Egress lighting equipment is exempted, and may remain at full power until the building is beyond the “normally occupied” schedule, at which time it may be placed on occupancy sensors and turned OFF completely.

A.   In aisle ways and open areas in warehouses, lighting shall be controlled with occupant sensing controls that automatically reduce lighting power by at least 50 percent when the areas are unoccupied. The occupant sensing controls must have independent zoning for each aisle, and the aisle zones must not extend beyond the aisle into the open area of the warehouse.

EXCEPTIONS: The following conditions exempt the lighting system from this requirement, but they must meet the additional listed requirements:

1.  In aisle ways and open areas in warehouses in which the installed lighting power is 80 percent or less of the value allowed under the Area Category Method, occupant sensing controls shall reduce lighting power by at least 40 percent (instead of the 50 percent required above).

2.  When metal halide lighting or high pressure sodium lighting is installed in warehouses, occupant sensing controls shall reduce lighting power by at least 40 percent (instead of the 50 percent required above). This is a limitation of the dimming or bi-level ballast technology for HID light sources.

Note that even if the exemptions apply, these only result in a lighting power reduction associated with aisles and open areas during “normally occupied” periods. These spaces are still required to comply with the applicable automatic shut-OFF controls in §130.1(c), which will produce deeper savings during the “after hours” periods

B.   In library book stack aisles meeting the following criteria, lighting shall be controlled with occupant sensing controls that automatically reduce lighting power by at least 50 percent when the areas are unoccupied:

1.    Library book stack aisles 10 feet or longer that are accessible from only one end.

2.    Library book stack aisles 20 feet or longer that are accessible from both ends.

The occupant sensing controls shall independently control lighting in each aisle way, and shall not control lighting beyond the aisle way being controlled by the sensor.

Note: This lighting is required to comply with the applicable automatic shut-OFF controls in §130.1(c).

C.   Lighting installed in corridors and stairwells shall be controlled by occupant sensing controls that separately reduce the lighting power in each space by at least 50 percent when the space is unoccupied. The occupant sensing controls shall be capable of automatically turning the lighting fully ON only in the separately controlled space, and shall be automatically activated from all designed paths of egress.

Note: These subsections indicate that the lighting must turn off the lights at least 50 percent, but the decision to turn off the lights fully may be made by the designer. There is no limit on the maximum the lights may be turned off, as there is in some other portions of the code.

The lighting in this section must also comply with the other portions of §130.1(c) that requires a full shutoff capability, which in the case of a partial-OFF sensor, would probably be triggered by a timeswitch.

5.4.3.6     Areas where partial OFF occupant sensing controls are required instead of complying with §130.1(c)1

The listed areas are required to have a Partial-OFF lighting control system INSTEAD of meeting the shutoff requirements of §130.1(c), however, that does not mean that they are not permitted to also meet those basic shutoff requirements, only that they are not required. This means that lighting in stairwells and corridors of hotels/motels and parking garages may operate on a full-time basis at the minimum setback level, and are not required to be shut OFF in the “after hours” periods as the majority of building lighting is required to be.

A.   Lighting in stairwells and common area corridors which provide access to guestrooms and dwelling units of high-rise residential buildings and hotel/motels shall be controlled with occupant sensing controls that automatically reduce lighting power by at least 50 percent when the areas are unoccupied. The occupant sensing controls shall be capable of automatically turning the lighting fully ON only in the separately controlled space, and shall be automatically activated from all designed paths of egress. This permits the lights to remain ON at a setback level continuously. Note that the zoning of the controls require careful consideration of paths of egress to ensure that the sensor coverage in the zone is adequate.

EXCEPTION: In common area corridors and stairwells in which the installed lighting power is 80 percent or less of the value allowed under the Area Category Method, occupant sensing controls shall reduce power by at least 40 percent (instead of the 50 percent required above).

B.   In parking garages, parking areas and loading and unloading areas, the general lighting shall be controlled as follows:

1.   By occupant sensing controls having at least one control step between 20 percent and 50 percent of design lighting power.

2.   No more than 500 watts of rated lighting power shall be controlled together as a single zone.

3.   A reasonably uniform level of illuminance shall be achieved in accordance with the applicable requirements in Table 5-1 (Table 130.1-A of the Energy Standards).

4.   The occupant sensing controls shall be capable of automatically turning the lighting fully ON only in each separately controlled space.

5.   The occupant sensing controls shall be automatically activated from all designed paths of egress.

This states that the lighting power must be reduced by at least 50 percent of the original lighting power, and that the lighting must be reduced while maintaining similar levels of uniformity to the full power conditions. Note that the zoning of the controls require careful consideration of paths of egress to ensure that the sensor coverage in the zone is adequate, and the wattage limits per zone will typically not permit entire floors of a garage to be on a single zone.

EXCEPTION: Metal halide luminaires meeting the following criteria shall be controlled by occupant sensing controls having at least one control step between 20 percent and 60 percent of design lighting power:

i.     Have a metal halide lamp plus ballast mean system efficacy of greater than 75 lumens per watt, (the lamp/ballast mean system efficacy is the rated mean lamp lumens at 40 percent of lamp life divided by the ballast rated input watts) and

ii.    Are used for general lighting in parking garages, parking areas and loading and unloading areas.

The requirement for metal halide luminaires to have a control step between 20 percent and 60 percent is a limitation of the dimming or bi-level ballast technology for HID light sources.

Note that interior areas of parking garages are classified as indoor lighting for compliance with §130.1(c)7B.

The parking areas on the roof of a parking structure are classified as outdoor hardscape and shall comply with the applicable provisions in §130.2. These controls provisions in §130.1(c)7B do not apply to open rooftop parking.

§130.1(c)7 indicates that the lighting must turn off the lights by at least 50 percent, but the decision to turn the lights off fully may be made by the designer.

The spaces listed in these sections are not required to meet the other requirements in §130.1(c) for full shutoff capability (these do not need to be connected through a timeswitch for unoccupied hours shutoff).

5.4.3.7     Requirements for Hotel and Motel Guest Rooms

'In addition to complying with the low-rise residential lighting Standards in accordance with §130.0(b), hotel and motel guest rooms shall have captive card key controls, occupancy sensing controls, or automatic controls such that, no longer than 30 minutes after the guest room has been vacated, lighting power is switched off.

EXCEPTION: A luminaire in a hotel or motel guest room meeting all of the following criteria is not required to have captive card key controls, occupancy sensing controls, or automatic controls under the following conditions.

iii.   Applies to one high efficacy luminaire (where high efficacy is defined in, §150.0(k) and TABLE 150.0-A or 150.0-B), and

iv.   That is switched separately from the other lighting in the room, and

v.    The switch for that luminaire is located within 6 feet of the entry door.

This one high efficacy luminaire is exempted so a person can turn on a light switch to find the captive card control.

5.4.4    Automatic Daylighting Controls

Daylighting can be used as an effective strategy to reduce electric lighting energy use by reducing electric lighting power in response to available daylight. §130.1(d) addresses mandatory requirements for daylighting.

Additional lighting controls are required in daylit zones to automatically shut off lighting when sufficient daylight is available.

Prescriptive daylighting controls are covered in subchapter 5.5 of this chapter.

5.4.4.1     Description of Terms

The following terms are used to describe the daylighting requirements in §130.1(d).

A.   General Lighting - Electric lighting that provides a uniform level of illumination throughout an area, exclusive of any provision for special visual tasks or decorative effect, exclusive of daylighting, and also known as ambient light.

Typical luminaires used for general lighting are troffers (prismatic, parabolic, or indirect diffusers), pendants (direct, indirect, or direct/indirect), high bay, low bay, and “aisle-lighter” fixtures. General lighting does not include display lighting (typically using directional MR, PAR, flood, spot, or wall washers) or ornamental lighting (such as drum fixtures, chandeliers, or projection lighting.)

B.   Window Head Height - The vertical distance from the finished floor level to the top of a window

C.   Daylit Zones - A region of space considered to be close to a source of daylight such as window, clerestory, roof monitor or skylight, where luminaires can be dimmed or switched in response to available daylight.

5.4.4.2     Definitions of Daylit Zones

Areas having skylights and windows are classified according to daylit zones. The three different types of daylit zones are defined as follows:

A.   Skylit Daylit Zone is the rough area in plan view under each skylight, plus 0.7 times the average ceiling height in each direction from the edge of the rough opening of the skylight, minus any area on a plan beyond a permanent obstruction that is taller than the following:

•      A permanent obstruction that is taller than one-half the distance from the floor to the bottom of the skylight.

The bottom of the skylight is measured from the bottom of the skylight well for skylights having wells, or the bottom of the skylight if no skylight well exists.

For the purpose of determining the Skylit Daylit Zone, the geometric shape of the Skylit Daylit Zone shall be identical to the plan view geometric shape of the rough opening of the skylight; for example, for a rectangular skylight the Skylit Daylit Zone plan area shall be rectangular, and for a circular skylight the Skylit Daylit Zone plan area shall be circular.

Note: Modular furniture walls shall not be considered a permanent obstruction.

Figure 5-4: Skylit Daylit Zone Diagram

Figure 5-5: Skylit Daylit Zone Diagram 2

B.     PRIMARY SIDELIT DAYLIT ZONE is the area in plan view and is directly adjacent to each vertical glazing, one window head height deep into the area, and window width plus 0.5 times window head height wide on each side of the rough opening of the window, minus any area on a plan beyond a permanent obstruction that is 6 feet or taller as measured from the floor.

Note: Modular furniture walls shall not be considered a permanent obstruction.

Figure 5-6: Primary Sidelit Daylit Zone Diagram 1

Figure 5-7: Primary Sidelit Daylit Zone Diagram 2

C.   SECONDARY SIDELIT DAYLIT ZONE is the area in plan view and is directly adjacent to each vertical glazing, two window head heights deep into the area, and window width plus 0.5 times window head height wide on each side of the rough opening of the window, minus any area on a plan beyond a permanent obstruction that is 6 feet or taller as measured from the floor.

Note: Modular furniture walls shall not be considered a permanent obstruction.

The daylighting controls in the Skylit Daylit Zone and the Primary Sidelit Daylit Zone are mandatory; they cannot be traded away for other efficiency measures when using the performance (whole building energy simulation) approach. The daylighting controls requirements in the Secondary Sidelit Daylit Zone is prescriptive and thus can be traded away for other efficiency measures in the performance approach. If code compliance is accomplished with the prescriptive approach then daylighting controls will be required in both the Primary and Secondary Sidelit Daylit Zones and these two zones must be controlled separately from each other.

Figure 5-8: Secondary Sidelit Daylit Zone Diagram 1

Figure 5-9: Secondary Sidelit Daylit Zone Diagram 2

5.4.4.3     Controlling Lighting in Daylit Zones

Mandatory daylighting controls for lighting in Skylit Daylit Zones and Primary Sidelit Daylit Zones are covered in this subchapter.

There are also prescriptive controls required for lighting in Secondary Sidelit Daylit Zones. The prescriptive daylighting controls are covered in Section 5.5 of this chapter.

Mandatory daylighting controls are required in the following daylit zones:

Luminaires providing general lighting that are in, or at least 50 percent in, the Skylit Daylit Zones or the Primary Sidelit Daylit Zones shall be controlled independently by fully functional automatic daylighting controls that meet the applicable device requirements in §110.9, and meet the applicable requirements below:

1.    All Skylit Daylit Zones and Primary Sidelit Daylit Zones shall be shown on the building plans.

2.    Luminaires in the Skylit Daylit Zone shall be controlled separately from those in the Primary Sidelit Daylit Zones.

3.    Luminaires that fall in both a Skylit and Primary Sidelit Daylit Zone shall be controlled as part of the Skylit Daylit Zone.

There are also prescriptive daylighting control requirements, which are covered in Section 5.5 of this chapter.

5.4.4.4     Automatic Daylighting Control Installation and Operation

For luminaires in Skylit Daylit Zones and Primary Sidelit Daylit Zones, automatic daylighting controls shall be installed and configured to operate according to all of the following requirements:

1. Photosensors shall be located so that they are not readily accessible to unauthorized personnel. The location where calibration adjustments are made to automatic daylighting controls shall be readily accessible to authorized personnel and may be inside a locked case or under a cover which requires a tool for access. Access to controls can be limited by placing locks or screws on enclosures or under a cover plate so a tool or key is needed to gain access. Though not required, commissioning and retro-commissioning of the control is simplified if the calibration adjustments are readily accessible to authorized personnel so that a lift or a ladder is not required to access the location where calibration adjustment are made.

Some controls have wireless remotes for adjusting settings; this is convenient as one person can be located at the edge of the daylit zone with a light meter and the wireless calibration tool and make the calibration adjustments without having to run back and forth between taking the measurement and making the adjustment.

2.   Automatic daylighting controls shall provide functional multi-level lighting levels having at least the number of control steps specified in Table 5-1 (Table 130.1-A of the Energy Standards).

EXCEPTION: Multi-level lighting controls are not required if the controlled lighting has a lighting power density less than 0.3 W/ft^2.

Note that when the requirements of §130.1(d) are triggered by the addition of skylights to an existing building and the lighting system is not recircuited, the daylighting control need not meet the multi-level requirements in §130.1(d). This is in accordance with §141.0(b)2G for alterations.

3.  For each space, the combined illuminance from the controlled lighting and daylight shall not be less than the illuminance from controlled lighting when no daylight is available.

In the darkest portion of the daylit zone (furthest away from windows or skylights) the control should not over-dim the lights; this portion of the daylighted area should not get darker as daylight levels increase, due to incorrect calibration of the controls.

4.   In areas served by lighting that is daylight controlled, when the daylight illuminance is greater than 150 percent of the design illuminance received from the general lighting system at full power, the general lighting power in that daylight zone shall be reduced by a minimum of 65 percent.

The best control would fully dim the system when daylight levels in the darkest portion of the daylit zone are at 100 percent of design illuminance, but the 150 percent / 65 percent requirement allows some tolerance for error while obtaining most of the energy savings.

EXCEPTIONS: Automatic daylighting controls are not required for any of the following conditions:

•    Rooms in which the combined total installed general lighting power in the Skylit Daylit Zone and Primary Sidelit Daylit Zone is less than 120 Watts.

•    Rooms which have a total glazing area of less than 24 square feet.

•    Parking garages complying with §130.1(d)3.

Figure 5-10 and Figure 5-11 plot the performance of switching and dimming automatic daylighting controls (photo controls). The performance is indicated in terms of lighting at the darkest point of the zone served by the controlled lighting.

The total lighting as plotted on the y-axis made up of both daylit and electric lighting contribution to total foot-candles(fc) at this darkest location in the zone served by the controlled lighting. Daylight plotted on the x-axis is just the daylight available at this darkest location.

Figure 5-10: Stepped Switching

In Figure 5-10, the light levels are given as a fraction of the reference or design foot-candles (fc). The bottom points of both controls indicate the total illuminance just after a stage of lighting has switched off. Both controls are compliant because the total illuminance at the darkest location in the zone served by controlled lighting just after switching off a stage of lighting is between 100 and 150 percent of the reference illuminance. The reference illuminance is the illuminance at this same location when there is no daylight (night time).

Figure 5-11: Dimming Controls

Figure 5-11 plots the performance of complying (“Acceptable” and “Max Savings”) and non-complying (“Under-dimming” and “Over-dimming”) controls. By fully dimming when daylight is 150 percent of the reference illuminance and also assuring that the total illuminance never falls below the reference illuminance (50 fc), the “Acceptable” control is minimally complaint with the requirements of §130.1(d)2D. Even greater savings are possible with the “Max Savings” control that maintains the 50 fc reference under all partially daylit conditions and is fully dimmed at 150 percent of the reference illuminance.

The “Under-dimming” control is only 30 percent dimmed when the daylight in the darkest portion of the zone served by the controlled lighting is at 150 percent of the reference illuminance (75 fc). The “Under-dimming” control does not save enough energy and thus is not code compliant. The “Over-dimming” condition reduces the electric lighting by more than the amount of daylight that enters the space. As a result, it actually is darker in portions of the space under partial daylight conditions than it is at night. In the short term, the “Over-dimming” control may save the most energy.

However, over the long term it is likely that the occupants may disable the control and the control would save no energy. As a result, the “Over-dimming” control is not code compliant.

These performance metrics of complying and non-complying control systems are the basis of the functional performance tests for the Automatic Daylighting Controls acceptance test. This test is described in detail in Chapter 10 – Acceptance Testing.

5.4.4.5     Parking Garage Daylighting Requirements.

In a parking garage area having a combined total of 36 square feet or more of glazing or opening, luminaires providing general lighting that are in the combined Primary and Secondary Sidelit Daylit Zones shall be controlled independently from other lighting in the parking garage by automatic daylighting controls, and shall meet the following requirements as applicable:

A.   All Primary and Secondary Sidelit Daylit Zones shall be shown on the building plans.

B.   Automatic Daylighting Control Installation and Operation.

Automatic daylighting control shall be installed and configured to operate according to all of the following requirements:

1.    Automatic daylighting controls shall have photosensors that are located so that they are not readily accessible to unauthorized personnel. The location where calibration adjustments are made to the automatic daylighting controls shall be readily accessible to authorized personnel but may be inside a locked case or under a cover which requires a tool for access.

2.    Automatic daylighting controls shall be multi-level, continuous dimming or ON/OFF.

3.    The combined illuminance from the controlled lighting and daylight shall not be less than the illuminance from controlled lighting when no daylight is available.

4.    When illuminance levels measured at the farthest edge of the Secondary Sidelit Zone away from the glazing of opening are greater than 150 percent of the illuminance provided by the controlled lighting when no daylight is available, the controlled lighting power consumption shall be zero.

EXCEPTIONS:

1.    Luminaires located in the daylight transition zone and luminaires for dedicated ramps. Daylight transition zone and dedicated ramps are defined in §100.1.

2.    When the total combined general lighting power in the Primary Sidelit Daylight Zones is less than 60 watts.

The primary differences between the automatic daylight control requirements in parking garages and the rest of interior lighting spaces are:

•    Primary and Secondary Zone are controlled together in parking garages whereas they must be separately controlled in other spaces. However, it is permissible that in either space type, a single sensor is used if the control system is capable of making the appropriate light level adjustments in each individual zone.

•    Daylighting controls in parking garages are permitted to use an  ON/OFF control strategy, whereas for all other interior spaces the control must be step switching or dimming

•      When sufficient daylight is present, controlled lighting in parking garages must be OFF whereas in other interior spaces the lighting power must be reduced by 65 percent. Egress lighting for the parking garage may be controlled, but the controls must employ a failsafe mechanism that ensures that the egress lighting is functioning and stays ON if the photocell fails.

Examples for complying with the mandatory daylighting controls requirements, and the prescriptive daylighting requirements are covered in Section 5.5 of this chapter.

5.4.5    Demand Responsive Controls

DEMAND RESPONSE is defined in §100.1 as short-term changes in electricity usage by end-use customers, from their normal consumption patterns. Demand response may be in response to:

1.  Changes in the price of electricity.

2.  Participation in programs or services designed to modify electricity use in response to wholesale market prices or when system reliability is jeopardized.

A.   Buildings larger than 10,000 square feet, excluding spaces with a lighting power density of 0.5 W/ft² or less, shall be capable of automatically reducing lighting power in response to a Demand Responsive Signal; so that the total lighting power of the non-excluded spaces can be lowered by a minimum of 15 percent below the total installed lighting power when a Demand Response Signal is received. Lighting shall be reduced in a manner consistent with uniform level of illumination requirements in Table 5-1 (Table 130.1-A of the Energy Standards).

EXCEPTION: Lighting not permitted by a health or life safety statute, ordinance, or regulation to be reduced shall not be counted toward the total lighting power.

B.   Demand responsive controls and equipment shall be capable of receiving and automatically responding to at least one standards-based messaging protocol by enabling demand response after receiving a demand response signal.

Figure 5-12: Potential inputs to receive Demand Response signal

Figure 5-12 illustrates example inputs that could be used to receive demand response signals. The inclusion of one of these types of control inputs, along with the proper design of the lighting system, will result in a lighting system that complies with the requirements of §130.1(e). There are several ways in which the lighting can be designed to meet the demand responsive requirements; outlined below are three specific compliance scenarios.

5.4.6    Lighting Control Acceptance Requirements (§130.4)

Before an occupancy permit shall be granted for a newly constructed building or area, or a new lighting system serving a building, area, or site is operated for normal use, indoor and outdoor lighting controls serving the building, area, or site shall be certified as meeting the Acceptance Requirements for Code Compliance.

A Certificate of Acceptance shall be submitted to the enforcement agency under §10-103(a) of Part 1 and §130.4(a), that:

1.   Certifies that all of the lighting acceptance testing necessary to meet the requirements of Part 6 is completed

2.   Certifies that the applicable procedures in Reference Nonresidential Appendix NA7.6, , NA7.8 have been followed.

3.   Certifies that automatic daylight controls comply with §130.1(d) and Reference Nonresidential Appendix NA7.6.1

4.   Certifies that lighting shut-OFF controls comply with §130.1(c) and Reference Nonresidential Appendix NA7.6.2

5.   Certifies that demand responsive controls comply with §130.1(e) and Reference Nonresidential Appendix NA7.6.3

6.   Certifies that outdoor lighting controls comply with the applicable requirements of §130.2(c) and Reference Nonresidential Appendix NA7.8.

7.   Certifies that lighting systems receiving the Institutional Power Adjustment Factor comply with §140.6(a)2J and Reference Nonresidential Appendix NA7.7.6.2

5.4.7    Lighting Certificate of Installation Requirements

Before any of the following applications will be recognized for compliance with the lighting requirements, the person who is eligible under Division 3 of the Business and Professions Code to accept responsibility for the construction or installation of features, materials, components, or manufactured devices shall sign and submit the Certificate of Installation for installation of the following items:

1.    Lighting Control System

2.    Energy Management Control System

3.    Track lighting integral current limiter

4.    Track lighting supplementary overcurrent protection panel

5.    Interlocked lighting systems service a single space

6.    Lighting controls installed to earn a lighting Power Adjustment Factor (PAF)

7.    Additional lighting wattage available for a videoconference studio

If any of the requirements in the Certificate of Installation fail the installation requirements, that application shall not be recognized for compliance with the Energy Standards.

5.4.8    Summary of Mandatory Controls

Table 5-2: Summary of Mandatory Nonresidential Lighting Control Requirements

Most spaces will have more than one overlapping control system controlling the lighting. Examples include:

•      Small offices will have a switch by the door and a Partial-ON occupancy sensor or Vacancy Sensor. If there is more than one luminaire in the office it will be required to be multi-level – most easily accomplished by a dimming luminaire. Typically these small offices will not have more than 120 Watts within one head height of the windows and thus often will not be required to have daylighting controls. For those offices within buildings greater than 10,000 square feet, an added demand control will also be required.

•      Large open plan offices are not required to use occupancy sensors to provide automatic off control. These spaces are required to have light switches (or manual dimmer) by the entrances and could either use occupancy sensors or a time switch with a timed override manual switch. Because the general lighting power density is likely greater than 0.5 W/ square foot, the lighting must be multi-level and likely dimming ballasts will be used. In large office spaces with perimeter windows it is likely that there will be more than 120 Watts of lighting in the primary Sidelit zone and thus the lights in the Primary Sidelit zone (within 1 head height of the windows) must be separately controlled by a daylighting control. If the building complies prescriptively the lighting in the Secondary Sidelit zone (between 1 and 2 window head heights from the perimeter windows) must also be controlled separately with daylighting controls. For those offices in buildings greater than 10,000 square feet, an added demand control will also be required.

•      Classrooms are required to have a manual switch by the entry and a Partial-ON occupancy sensor or Vacancy Sensor to automatically turn off lights when the space is unoccupied. Classrooms that have lighting power densities less than 0.7 W per square foot can meet the multi-level control requirements with a bi-level control. However, the lights that are within the Primary Sidelit zone must be controlled as in Table 130.1-A which requires at least 4 step of control for fluorescent luminaires. If the school is complying prescriptively, the lights in the Secondary Sidelit Zone are also required to control lighting as per Table 130.1-A. 'In 'addition this space must have demand response controls which also be controlled according to Table 130.1-A. As a result, many classroom lighting systems will comply with dimming ballasts controlled by a daylighting and demand response signal in the Sidelit Zones and by a manual dimming and demand response signal in the rest of the classroom. All of the lights will be controlled to turn off by an occupancy sensor when the room is vacated.

•      Warehouses that prescriptively comply with the standards will have enough skylights so that the at least 75 percent of the floor area will be in the skylight daylight zone before accounting for partitions and other obstructions that reduce the fraction of general lighting that is controlled. If the LPD of the warehouse lighting system is less than 0.5 W per square foot, the multi-level control and the demand responsive control requirements do not apply. However the lighting in the skylit daylight zone must be controlled by a multi-level daylighting control. If the lighting is HID (metal halide or high pressure sodium) the multi-level daylighting controls are only required to be 2 level (high and low) plus off. 'In 'addition, open area and aisle lighting must be controlled by occupancy sensors that reduce lighting power by at least 50 percent (or 40 percent if the lighting is HID). The multi-level control can be accomplished with step dimming or continuous dimming ballasts though it is possible to accomplish the control with a 2 lamp HID luminaire or a 4 or more lamp fluorescent luminaire.

•      Retail spaces typically will have the area switches in a location that is not accessible to the general public. General lighting, display lighting and ornamental lighting are required to be separately switched. Automatic shut-off controls will typically be time switch based with local timed override switches. With the prescriptive daylighting requirements applying to large open spaces with floor areas greater than 5,000 square feet and ceiling heights greater than 15 feet, many retail spaces are prescriptively required to daylight at last 75 percent of the space. Only the general lighting is required to be controlled with automatic daylighting controls; display lighting and ornamental lighting are allowed to be fully on regardless of how much daylight is entering the space.