By Charles Knuffke
Since 2013 California has updated its Title 24, Part 6 energy code every three years. Whether you are living in California, doing business in the state, or interested in the new requirements that might also appear in the IECC or ASHRAE/IES 90.1, it is worthwhile to be aware of the updates. What follows is what I believe to be the most significant changes in the 2022 version, which go into effect January 1, 2023.
The demand response requirements in the new code received a significant rewrite. One helpful change is that the California Energy Commission (CEC) redefined the “communication” between the virtual end node (the hardware/software that communicates with the grid operators) and the demand-responsive controls. Previous versions of Title 24 were prescriptive in requiring Wi-Fi, Ethernet, Zigbee, BACnet or hard-wiring. This was concerning since calling out specific communication types might limit other technologies in the future, but more worrisome was the inclusion of the term “hard-wiring,” as it was not listed in the definition section of the code.
The CEC removed the previous language and replaced it with “wired or wireless bi-directional communication pathway.” This new language eliminates systems that did not provide a communication protocol to the demand-responsive lighting system and instead used a simple dry-contact closure.
Another interesting change in this section is the redefinition of the metric used to determine if a demand-responsive lighting system is required. Instead of using 10,000 sq ft as a threshold, the code now requires a demand-responsive system when there is more than 4,000 watts of lighting load. However, the devil is in the details—in this case, the devil is in the exemptions.
Previously, the code exempted spaces with a lighting power density (LPD) less than 0.5 watts per sq ft, but now the text references lighting covered in the multilevel lighting control section. While subtle, this change in phrasing is extremely significant. The multilevel lighting control section only applies to general lighting, and while it also exempts spaces with an LPD of less than 0.5 watts per sq ft, it also exempts any space less than 100 sq ft—which eliminates many individual offices from the calculation.
The rationale is reasonable: Why have demand response apply to spaces that do not require dimmable luminaires? Yet, the original demand-response requirement in the 2008 code applied to all lighting in retail establishments over 50,000 sq ft—I fear this leaves the power usage of many other lighting loads on the design table, since they too, could be turned Off if needed. Between the new language and the ever-increasing efficacy of LED luminaires, I fear there will be fewer installations with demand-responsive lighting controls.
One last item of note is that if a facility is required to have a demand-response lighting control system, and the building also requires plug-load controls, controlled outlets must be capable of being turned Off in response to a demand-response system. Note this does not mean that all controlled outlets must turn Off on a demand-response signal, merely that some group of them could be included in the demand-response plan should the owner so desire.
While Title 24 often leads advances in energy code requirements, it is not above including language that first appeared in the other major codes. Similar to how it is worded in IECC 2018, Title 24 mandates occupancy sensors in large, open-office areas (the code previously required this for office areas less than 250 sq ft). Also similar to IECC, Title 24 requires occupancy sensors be set up in zones of no more than 600 sq ft. However, the code allows lighting in a zone to turn On to any level the designer wants when it becomes occupied, and as long as any zone in an open office is occupied, designers do not have to have lighting go full Off, but can—if they wish—go to any level 20% or less.
It will be interesting to see how this modification influences office designs. The biggest beneficiary of this language change is luminaire-level lighting controls (LLLC). The number of switch legs that might be needed in a large, open-office area may cause contractors to look favorably toward buying luminaires with an onboard occupancy sensor (or daylight sensor, or dimming controller) already included. There is some question about what the best way is to handle manual area controls in such spaces, but there is no doubt of the benefit to the owners being able to rezone large areas with software rather than wiring changes.
Though the IECC has included this language for some years, once California adopts this language, the situation may be similar to when plug loads were adopted in California. Controlled receptacles were originally required under ASHRAE 2010, but because code enforcement around the country was uneven, controlled receptacles seemed to be the exception rather than the rule. But when California added the controlled-receptacles requirement to Title 24 in 2013, it was enforced immediately and vigorously—thus leading to new product solutions.
A new electrical subsect ion appearing in the nonresidential section of the code will have a large impact on construction in California. In the prescriptive requirement section of Title 24, there is now a mandatory requirement for both photovoltaics and battery-storage systems on a range of building types. This is as striking a move toward the cause of decarbonization as any I’ve seen.
The question is, with the new mandate going into effect in less than one year, can the industry provide all the hardware necessary to meet these requirements? Do the designers have time to evaluate and explain the additional cost impact to architects and building owners?
Currently the Title 24 energy code is divided between residential and nonresidential projects. Each has its nuances: residential focuses on high-efficacy lighting, while nonresidential focuses on the amount of power projects use. There is some overlap when dealing with spaces such as fire stations, hotels, dormitories and others—but it wasn’t difficult to understand how to apply the respective codes to these types of projects. The CEC, however, adopted a proposal put forth by a Codes and Standards Enhancement (CASE) team that multifamily buildings should now have their own code sections. While the new multifamily sections duplicate much of the lighting and mechanical language that is in the residential and the nonresidential sections, there are now three new major sections that will add over a hundred pages to the energy code.
Many designers already have a difficult time keeping track of the code’s many requirements, and it will be even more difficult in the future when the language in either the residential or nonresidential sections start to differ from what is in the multifamily section.
The residential contractors may be the most affected by this change as many cities have smaller buildings shared by three or four families. Previously, a residential contractor would have been comfortable with the work that was involved because multifamily spaces were mainly residential. However, once these buildings start following the new multifamily requirements, it can require an understanding of how the nonresidential code sections apply to common areas—something residential contractors have never had to worry about.
While the above are the major additions and changes to the code, there are innumerable other edits throughout; designers and installers need to understand the totality of those deviations before they start working on projects that go out for permit after the start of the New Year. Until then, my suggestion is to reach out to manufacturers and their representatives, local IES groups, and other educational resources such as Energy Code Ace and the Lighting Control Association for help in understanding all the changes in California’s 2022 Energy Code.