Most comfort problems in LA homes come from how a system was installed, not which brand is on the box. Oversized units short cycle and leave the house clammy, undersized ones run nonstop on a 108-degree day, and leaky ducts in a hot attic waste a big share of what you pay to cool. Our approach to AC installation in Los Angeles is built to avoid all three: size it properly, install it to code, test it, and document it.
What Is Included in Every AC Installation
- Load calculation (Manual J style) so the system is sized to your actual house, not a rule of thumb or the size of the old unit
- Written quote with exact model numbers for the condenser, coil or air handler, furnace if included, and thermostat, before any work starts
- Permit pulled with LADBS or your city's building department
- Title 24 compliance and HERS coordination where the scope requires it
- Utility rebate paperwork filed for programs that currently apply
- Floors covered and the work area protected
- Site cleaned daily, not just at the end
- Old equipment hauled away and refrigerant recovered properly
- Full startup and testing before we leave
These are the steps cheaper bids quietly skip. When you compare quotes, ask each contractor whether they include a load calculation, a permit and Title 24 testing. If the answer is vague, that is where the price difference is coming from.
Why Sizing Matters More Than Brand
The old way of sizing was a square-footage guess, or just matching whatever tonnage was there before. In older LA homes that have been remodeled, re-roofed, re-windowed or expanded, the old size is rarely the right one.
What a load calculation looks at
- Square footage, ceiling heights and room layout
- Window size, glass type and which direction each wall faces
- Attic and wall insulation levels
- Where the ducts run (a hot attic changes everything) and how leaky they are
- Local design temperatures, which are much harsher in the Valley than near the coast
An oversized AC blasts cold air, satisfies the thermostat quickly and shuts off before it removes much humidity or evens out the rooms. That on-off cycling also wears parts faster. An undersized AC runs flat out during the August through October heat waves and still falls behind. A properly sized system runs longer, steadier cycles and keeps upstairs and downstairs closer together.
Permits, Title 24 and HERS Testing
In California, AC and heat pump replacements generally need a mechanical permit, and Title 24 Part 6 energy code applies to HVAC changeouts. Depending on the scope of work, a third-party HERS rater may need to verify items like refrigerant charge, duct leakage and airflow before the permit is finaled.
Skipping the permit can come back to bite you when you sell the house or file for a rebate, and it means nobody checked the work. We pull the permit, coordinate inspections and HERS testing, and give you the paperwork. For a full breakdown, read our guide to HVAC permits and Title 24 in Los Angeles.
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AC Replacement and the New A2L Refrigerants
Under the EPA AIM Act, new residential air conditioners and heat pumps manufactured from January 1, 2025 use lower-GWP A2L refrigerants such as R-454B or R-32. That has a few practical effects on an AC replacement:
- New systems are designed around the new refrigerant, so the outdoor unit and indoor coil are typically replaced together as a matched system.
- A2L refrigerants are classified as mildly flammable, so equipment includes added safety features such as leak detection sensors in some designs, and installation follows updated code requirements.
- Your existing line set may or may not be reusable depending on its size, condition and routing. We check it rather than assume.
If your current R-410A system is still healthy, you do not have to replace it. We cover the timing question in the R-410A phase-out and what it means for California homeowners.
SEER2 and Efficiency in Southern California
Since January 2023, efficiency is rated in SEER2 for cooling and HSPF2 for heat pump heating. California sits in the DOE Southwest region, which has higher minimum efficiency for central AC than much of the country. Higher SEER2 equipment, especially variable-speed models, can pay off in the Valley where systems run hard for months. Near the coast, the math is different. We will show you the options side by side and let you pick what fits your house and budget.
If you heat with an old gas furnace, this is also a good moment to consider a heat pump instead of a straight AC. One system handles both cooling and heating, and utility rebate programs often favor heat pumps.
Installation Day: Step by Step
- Arrival and protection. We walk the job with you, cover floors along the work path and protect the area around the indoor unit.
- Removal. Refrigerant is recovered from the old system, and the old condenser, coil and any replaced equipment are disconnected and removed.
- Set the new equipment. The outdoor unit goes on a level pad or bracket with proper clearances; the indoor coil or air handler is set and sealed to the plenum.
- Refrigerant piping. The line set is replaced or cleaned and reconnected, then brazed or flared to spec.
- Pressure test and evacuation. We pressure test for leaks and pull a deep vacuum to remove moisture before releasing refrigerant.
- Electrical and controls. Disconnect, wiring, breaker sizing and thermostat are installed and checked.
- Condensate drain. A properly sloped drain with a safety float switch or secondary pan, so a clog shuts the system off instead of soaking a ceiling.
- Startup and testing. We verify charge, airflow, temperatures and controls, and make sure the system is working properly before we leave.
- Walkthrough and cleanup. We show you the thermostat, filter location and what to watch for, haul away the old equipment and leave the site clean.
"Had a new HVAC system installed at my home in Burbank by Back2Cool and had a really good experience with them. The guys were professional, showed up on time, and explained everything clearly before starting the work. The installation went smoothly, they kept everything clean, and made sure the new system was working properly before they left. They were also very easy to communicate with throughout the whole process, which I really appreciated. Overall, very happy with the work and the new system. I'd definitely recommend Back2Cool to anyone looking for HVAC installation or service in the Burbank area!!"
Solange F. · Thumbtack
Do Not Forget the Ducts
A new high-efficiency system connected to old, leaky ductwork in a hot attic will never perform the way it should. Many 1920s to 1960s LA homes have ducts that are crushed, disconnected or barely insulated. When ducts are altered or replaced, Title 24 may require duct leakage testing. We inspect ducts as part of every replacement quote and tell you honestly whether they can stay. See our duct cleaning, repair and replacement page for more.
Homes with no ducts at all, or an ADU, garage conversion or addition, are often better served by a ductless mini-split.
Get an AC Replacement Quote
Send us a photo of your current system and we will tell you straight whether it needs replacing or just a repair. If replacement makes sense, we schedule a visit for measurements and give you a written quote with exact model numbers. We install across Sherman Oaks, Burbank, Glendale, Pasadena and greater Los Angeles. Call (626) 635-4095.
