Compliance guide

Title 24 Energy Compliance for HVAC in California: A Homeowner's Guide

Mister Cool technician with the wrapped service van on a Los Angeles street

What Title 24 Actually Means for Your HVAC Project

Title 24 is California's energy code, and it applies to nearly every HVAC installation and replacement in the state.

Title 24 refers to the California Building Energy Efficiency Standards. The California Energy Commission (CEC), the state agency that sets and updates these rules, writes Title 24 to govern how efficient new and replacement HVAC equipment must be. It sets minimum efficiency ratings for equipment. It also requires specific installation quality checks before a permit can be closed.

Here's what Title 24 actually controls: which equipment can be legally installed in your home, whether an independent inspector must verify the work, and how long your installation project takes from start to finish.

If you're replacing an air conditioner, installing a new furnace, or adding a heat pump in Los Angeles, Title 24 applies to your project. This guide explains what that means, in plain language, step by step.

Why Title 24 Hits Differently in Los Angeles

Los Angeles sits across multiple CEC climate zones, and each one carries its own Title 24 thresholds.

The California Energy Commission divides California into 16 climate zones. These CEC Climate Zones, geographic areas with distinct temperature and humidity profiles, determine exactly which efficiency minimums and testing requirements apply to your home. Los Angeles doesn't sit neatly in one zone.

Mister Cool technician checking an outdoor AC unit beside a Los Angeles home

Homes in the San Fernando Valley fall generally into CEC Climate Zone 9. Homes in Pasadena, Burbank, and Glendale overlap into Zones 9 and 10. Inland Empire cities like Rancho Cucamonga, Fontana, and Ontario are primarily in Zone 10. Orange County cities, Anaheim, Santa Ana, Irvine, span Zones 8 and 10 depending on proximity to the coast.

Why does this matter? The minimum SEER2 rating, the efficiency floor for equipment, and duct leakage thresholds vary by zone. A system that qualifies in one part of Greater Los Angeles may not meet the threshold in another. Your contractor needs to know which zone your home is in before recommending equipment. That's where Title 24 compliance begins.

Requirement by requirement

The Full Picture: Title 24 Requirements for HVAC Installations

Title 24 has four main requirements every homeowner should understand before scheduling HVAC work.

SEER2 Minimums: What Equipment Can Be Installed

SEER2, or Seasonal Energy Efficiency Ratio 2, is the updated efficiency rating standard adopted in 2023. It replaced the original SEER rating system with a more accurate test method. Title 24 sets minimum SEER2 thresholds for air conditioners and heat pumps installed in California, equipment rated below those thresholds cannot be legally installed as a replacement in most situations.

For most of Greater Los Angeles, the current minimum for a split-system central air conditioner is 15.2 SEER2 for systems under three tons. Equipment specs must be confirmed against CEC Title 24 equipment lists before purchase. Your contractor should verify this at the estimate stage, not after equipment arrives on the job site.

HERS Testing: Why an Independent Inspector Is Involved

A HERS Rater, a Home Energy Rating System inspector certified by the CEC, is required on most Title 24-regulated installations. The HERS Rater is not the installing contractor. They are an independent third party whose job is to verify that the installation meets Title 24 requirements after the work is complete.

The HERS Rater must be scheduled separately. They verify equipment efficiency ratings, measure airflow, and in most cases perform duct leakage testing. Their sign-off, recorded in the CEC's online registry, is what allows the mechanical permit to close. Without it, the permit stays open.

An open permit shows up in city records and can complicate a home sale, trigger a flag during a refinance, or create liability if something goes wrong later. Permit closure is the step that makes the job genuinely complete.

Duct Leakage Testing: What It Measures and Why It's Required

Duct Leakage Testing measures how much conditioned air escapes the duct system before it reaches the living space. The test pressurizes the duct system and measures the leakage rate against a percentage threshold. Title 24 sets that threshold, and if duct leakage exceeds it, the installation cannot pass HERS verification.

This test is required on most HVAC replacements involving the duct system. In Los Angeles, where a significant portion of homes have ductwork installed in attics that reach 150°F in summer, duct leakage is a genuine efficiency concern. Sealing ducts before a HERS test is a standard part of a proper Title 24 installation.

Permit Closure: The Step That Completes the Job

Permit Closure is the final step. The city or county building department, in Los Angeles, that's LADBS, inspects the work and formally closes the mechanical permit. HERS verification must be complete before this step can happen.

A permit that is pulled but never closed remains open in city records. The system may run fine, and the homeowner may never know, until it surfaces during a home sale or refinance years later. Permit closure is what separates a finished job from an incomplete one.

Refrigerant manifold gauge hoses against an outdoor condenser on a Los Angeles concrete pad, with a permit document in a clear sleeve beside it

In practice

Common Scenarios: How Title 24 Plays Out for LA Homeowners

Title 24 works differently depending on the project type, here are three situations homeowners actually face.

PasadenaDuct test required

Scenario 1: Replacing a central AC system in a Pasadena home.

A homeowner in Pasadena replaces a 15-year-old central air conditioner. The home is in CEC Climate Zone 9. The contractor recommends a qualifying SEER2 system, pulls a mechanical permit through the City of Pasadena, and schedules a HERS Rater to perform duct leakage testing before the final inspection. The rater finds one duct section exceeding the leakage threshold. The contractor seals it. The rater returns, verifies compliance, and records the results in the CEC registry. The permit closes. The job is complete.

AnaheimNo duct test

Scenario 2: Installing a new ductless mini-split in an Anaheim rental property.

A landlord in Anaheim installs a ductless mini-split system in a unit without existing ductwork. Because there are no ducts, duct leakage testing does not apply. But SEER2 minimums still apply to the equipment. The HERS Rater verifies refrigerant charge and airflow. The permit closes through the City of Anaheim. This is often a faster compliance process than a full duct system replacement, but it still requires proper permitting and HERS verification.

BurbankHERS required

Scenario 3: An emergency AC replacement in Burbank in July.

A homeowner in Burbank wakes up to a failed air conditioner during a heat wave. The urgency is real. The contractor pulls an emergency mechanical permit and completes the installation quickly. The HERS Rater still needs to be scheduled, and that appointment typically takes a few business days. The permit closes after verification. Speed and compliance work together when coordination begins at the estimate stage.

A Straight Answer on How We Handle Title 24 from the Start

At Mister Cool California, the Title 24 compliance conversation happens at the estimate, before any equipment is ordered.

The most common compliance gap we see comes from timing. The HERS Rater must be scheduled in advance. If duct leakage testing reveals an issue, which it sometimes does in older LA-area homes, there is remediation work to complete before the rater can sign off. When that coordination isn't part of the plan from the beginning, delays happen after installation is already underway.

A technician's hand pointing to a line on a printed estimate on a clipboard beside an outdoor condenser at a Los Angeles home

We identify HERS requirements at the estimate. Homeowners know before scheduling what compliance involves, what the HERS Rater will check, and what happens if duct testing reveals an issue. That conversation closes the gap between a running system and a closed permit.

Mister Cool California holds CSLB C-20 license #1143117, the California contractor credential required to pull mechanical permits and perform Title 24-regulated HVAC work through LADBS and other Greater Los Angeles building departments. That license is publicly verifiable through the CSLB lookup tool.

Ask about your job

When to Bring in a Licensed HVAC Contractor for Title 24 Work

Any HVAC replacement or new installation in Los Angeles that requires a permit also requires Title 24 compliance.

If you're replacing a central air conditioner, installing a new furnace, adding a heat pump, or installing a ductless system, a mechanical permit is required. And where a permit is required in California, Title 24 compliance is part of that process.

The right time to ask about Title 24 is before the estimate is accepted. Ask your contractor these questions:

Is this installation subject to SEER2 minimums under Title 24?

Will a HERS Rater be required, and who schedules that?

Does this project require duct leakage testing?

Who pulls the mechanical permit, and what does permit closure involve?

See how Los Angeles HVAC permits work

A licensed C-20 contractor who routinely handles Title 24-compliant installations should walk through every step clearly. The goal isn't just a running system, it's a closed permit, a compliant installation, and no surprises when you sell or refinance your home.

Areas We Serve

Mister Cool California serves Greater Los Angeles, Orange County, and the Inland Empire.

We handle Title 24-compliant HVAC installations across Los Angeles, West Hollywood, Beverly Hills, Burbank, Glendale, Pasadena, Santa Monica, Culver City, Inglewood, Hawthorne, Torrance, Downey, Long Beach, Carson, Compton, Gardena, Whittier, Norwalk, El Monte, Alhambra, Monterey Park, San Gabriel, Redondo Beach, Lakewood, Anaheim, Fullerton, Santa Ana, Garden Grove, Orange, Costa Mesa, Huntington Beach, Irvine, Newport Beach, Mission Viejo, Laguna Beach, Lake Forest, Ontario, Rancho Cucamonga, Fontana, San Bernardino, Riverside, Moreno Valley, Pomona, Baldwin Park, and surrounding communities.

Book a service call

Next Steps: Get Your Compliance Questions Answered Before Work Starts

The best time to ask about Title 24 is before any equipment is ordered or installation is scheduled.

If you're planning an AC replacement, furnace installation, or heat pump upgrade anywhere in Greater Los Angeles, start the compliance conversation early. Know which CEC climate zone your home is in, whether HERS testing applies, and what duct leakage testing will require.

Mister Cool California handles that conversation at the estimate, not after the job is done.

Call us at (323) 770-7737 or email info@mistercoolcalifornia.com to ask about your specific project. We'll walk through what Title 24 requires for your home and confirm the compliance process is clear before work begins.

Book a service call Call (323) 770-7737

Keep reading