What Is SEER and Why Does It Matter?

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently an air conditioner cools your home over an entire season, expressed as BTUs of cooling per watt-hour of electricity consumed. Higher SEER = less electricity used to cool the same space.

Think of SEER like MPG for your car. A higher SEER rating means lower operating costs — especially important in Los Angeles where AC runs 5–6 months per year and LADWP rates are among California’s highest.

SEER2 vs. SEER — What Changed in 2023

In 2023, the Department of Energy switched to SEER2 ratings using a more realistic test standard. SEER2 uses higher external static pressure (0.5 in. w.g. vs 0.1 in.) that better reflects real-world duct systems. The result: SEER2 ratings run 4–5% lower than old SEER ratings for the same equipment.

Old SEER Rating	Approx. SEER2 Equivalent	California Legal for New Install?
13 SEER	12.5 SEER2	No (below minimum)
14 SEER	13.4 SEER2	No (Southwest requires 15 SEER2)
16 SEER	15.2 SEER2	Yes
18 SEER	17.2 SEER2	Yes
20 SEER	19.0 SEER2	Yes
26 SEER	24.6 SEER2	Yes — top residential efficiency

How SEER Rating Affects Your LA Electric Bill

The formula: Annual Cooling Cost = (Cooling Hours × BTU Capacity) ÷ (SEER × 1000) × Rate/kWh

For a 3-ton (36,000 BTU) system in Van Nuys running 1,200 hours/year at $0.22/kWh (LADWP Tier 2):

SEER2 Rating	Annual Cooling Cost	Savings vs 10 SEER
10 SEER	$950/yr	—
14 SEER	$678/yr	$272/yr
16 SEER	$594/yr	$356/yr
18 SEER	$528/yr	$422/yr
20 SEER2	$475/yr	$475/yr
26 SEER2	$365/yr	$585/yr

Is Higher SEER Worth the Premium in Los Angeles?

Upgrade	Extra Cost	Annual Savings	Payback Period	Verdict
14 → 16 SEER2	$500–$800	$80–$120	5–7 yrs	Worth it — small premium
16 → 18 SEER2	$800–$1,500	$100–$180	6–9 yrs	Worth it for Valley homes
16 → 20 SEER2	$1,500–$2,500	$150–$250	7–12 yrs	Worth it if staying 10+ yrs
16 → 26 SEER2	$3,000–$5,000	$200–$350	12–18 yrs	Marginal — mainly for rebates

California Efficiency Requirements

• Minimum for new central AC installs (Southwest region): 15 SEER2
• Heat pump heating minimum: 8.8 HSPF2
• Packaged units minimum: 14 SEER2
• All systems must be tested and certified under new M1 standard
• LADWP rebates start at 16 SEER2 — there’s no rebate for minimum-compliant equipment

Frequently Asked Questions

What is the minimum SEER2 rating required in California?

California requires a minimum 15 SEER2 (equivalent to about 15.2 old-scale SEER) for new central AC installations as of 2023. The Southwest region has stricter requirements than the rest of the country. Installing a system below this rating is illegal for new installs in CA.

What is the difference between SEER and SEER2?

SEER2 uses a more realistic test procedure (M1 blower standard) that simulates real-world conditions with slightly higher external static pressure. A 16 SEER unit is roughly equivalent to 15.2 SEER2. SEER2 ratings are typically 4–5% lower than the original SEER rating for the same equipment.

How much money does a higher SEER AC save in Los Angeles?

In LA, upgrading from a 10 SEER system to a 16 SEER2 system typically saves $300–$600/year on electricity. Upgrading to a 20 SEER2 saves an additional $150–$300/year over 16 SEER2. The exact savings depend on your home size, usage hours, and LADWP rate tier.

Is it worth paying more for a 20+ SEER system in LA?

Yes, for homes that run AC heavily (May–October in the Valley). A 20 SEER2 system costs $1,500–$3,000 more than a 16 SEER2 system but saves $200–$400/year. Payback period is 4–8 years — reasonable given a 15–20 year system lifespan.

Does SEER rating affect heating efficiency too?

No. SEER measures cooling efficiency only. For heating, look at HSPF2 (Heat Seasonal Performance Factor) for heat pumps, or AFUE for gas furnaces. A heat pump with high SEER2 and high HSPF2 is efficient at both heating and cooling.