HVAC controls in California operate under the 2025 Title 24 energy code, effective for permits filed on or after January 1, 2026, with the 2022 cycle still governing projects permitted earlier. The 2025 cycle favors heat pump space and water heating and tightens envelope and ventilation requirements, which adds electrified equipment and more control points across the commercial market in Los Angeles, the Bay Area, San Diego, and Sacramento.
Functional Devices, Inc. builds three product categories that California contractors specify together to handle that load: RIB® (Relay-In-a-Box®) relays, RIB® current sensors, and RIB® prepackaged power supplies, providing switching, verification, and control power from one product line.
RIB® Relays for California Commercial HVAC Switching
RIB® relays are the interface between building automation system (BAS) binary outputs and line-voltage HVAC load circuits, keeping the controller electrically isolated from the loads it switches. The RIB2401B (20A SPDT, 24 VAC/DC or 120 VAC coil) handles fan coil unit control and rooftop unit enable circuits across most configurations in California commercial construction. For light-duty switching such as damper actuators and pilot duty, the RIBU1C (10A SPDT, universal 10–30 VAC/DC or 120 VAC coil) is a widely specified general-purpose relay. Higher-current or dual-circuit loads use the RIB24P30 (30A DPDT, 24 VAC/DC coil).
Large California facilities often stage multiple rooftop units or chiller stages to meet peak cooling demand, and each stage is a switching point that has to isolate the controller from the line-voltage circuit it drives. Matching coil voltage to the control circuit, typically 24 VAC from a BAS output, is the basic selection step.
On the California ISO (CAISO) grid, demand response events call for fast, dependable load shed. RIB® relays at HVAC equipment switching points make those commands reliable, and because they are UL Listed as complete assemblies, they clear inspection without field reassembly.
RIB® Current Sensors for Title 24 Verification
Switching equipment is half the picture; confirming it runs is the other half. A RIB® current sensor reads the load directly rather than inferring status from a command, which lets a BAS tell a tripped breaker from a normal off cycle.
Split-core models install around an existing conductor without disconnecting wiring. The RIBXGTA is a split-core adjustable current switch with a 0.75–150A sensing range and dry contact output. For electronically commutated motor (ECM) fans and variable-speed pumps common in California high-efficiency builds, the RIBXGTA-ECM reads the low, variable draw those motors produce down to 0.25A. Title 24 acceptance testing of mechanical controls calls for functional verification, and equipment-level current feedback supports that documentation at commissioning.
RIB® Prepackaged Power Supplies
BAS controllers, sensors, and interposing relays all need reliable 24V control power. RIB® prepackaged power supplies deliver it in a compact, prewired enclosure with transformer and breaker included, so there is no separate transformer to source or field-assemble. In California's inland climate zones, where Central Valley and Inland Empire rooftop ambient temperatures run high through the cooling season, a thermally rated supply in the control circuit reduces callbacks.
Frequently Asked Questions
Does Title 24 require specific HVAC relays?
No. Title 24 sets energy performance and control requirements for the system; it does not specify relay model numbers. Device selection is driven by the load, the control voltage, and the application.
What confirms equipment is running for Title 24 acceptance testing?
A current sensor reads the actual current draw at the equipment, which distinguishes a running motor from a commanded-on state that did not start. Confirm the acceptance testing requirements for your scope with the Authority Having Jurisdiction.
Source RIB® Controls for California HVAC Projects
For a California HVAC project, the RIB® relays, current sensors, and prepackaged power supplies covered here are stocked through authorized Functional Devices distributors statewide, with local availability across Los Angeles, the Bay Area, San Diego, and Sacramento. Sourcing them from one distributor keeps the switching, verification, and control power for a job on the same order. Browse the RIB® relay lineup, or find an authorized Functional Devices distributor in California.