SEER2 Light Commercial Guide: Cut Energy Costs and Stay Code-Compliant

Why this matters now SEER2 and your small commercial space

If you run a shop, office, or restaurant, your rooftop unit (RTU) or split system works hard all summer. SEER2 is the updated efficiency yardstick for these systems, and it’s not theory—it affects what you can buy and what it costs to run. Since installations after January 1, 2023 must meet current SEER2 rules, choosing the wrong model can delay permits or waste energy dollars. Think of SEER2 as the “miles per gallon” of cooling, only measured across a whole season and with real-world test conditions that better match how units actually run on rooftops and behind buildings. Our goal here is simple: help you understand what’s required, pick compliant equipment, and keep it running at its rated efficiency without fluff. If you need help matching equipment, our Design Center and Sizing Guide make it easier.

SEER vs. SEER2 plain-English difference

Old SEER testing lived in a “perfect lab.” SEER2 raises the bar: it uses a higher external static pressure and updated test procedures to reflect real ductwork and real roofs, not perfect test stands. That means a SEER2 rating is a better predictor of your actual summer power bill. Higher SEER2 = lower seasonal energy use. For light-commercial systems at ≤65,000 Btu/h, SEER2 applies to both rooftop units and split systems. You’ll see SEER2 on spec sheets, quotes, and AHRI or ENERGY STAR® listings. 

When comparing two quotes, compare SEER2 to SEER2 (not SEER). If an older brochure lists SEER only, ask your rep for the SEER2 equivalent or the current AHRI certificate. When in doubt, we can help you cross-check paperwork in our Help Center.

Does SEER2 apply to your equipment?

If your cooling equipment is ≤65,000 Btu/h (about 5.4 tons) and is a rooftop unit or split system, SEER2 absolutely applies. That covers many small offices, clinics, retail bays, restaurants, and tenant build-outs. Three quick checks:

1. Nameplate capacity—look for MBH or tons.

2. Configuration—RTU (single packaged) or split (condenser + indoor air handler).

3. Manufacture date—pre-2023 units may be “grandfathered” in limited cases, but new installs after 1/1/2023 must meet the current SEER2 minimums.

If you’re planning a replacement, this is the perfect time to confirm duct condition and airflow so you don’t undercut efficiency on day one. Need parts for a refresh? See Commercial HVAC Accessories for compatible components.

Know the numbers minimums and ENERGY STAR® targets

Here are the must-meet thresholds for light-commercial systems (≤65,000 Btu/h):

• Split systems in Southern (Southeastern) states: ≥14.3 SEER2 for AC and heat pumps; heat pumps also need ≥7.5 HSPF2.

• Three-phase small commercial AC/HP (≤65,000 Btu/h): DOE levels align closely with ASHRAE 90.1, with splits typically ~13.4–14.3 SEER2 depending on configuration.

• ENERGY STAR® (very small commercial <65,000 Btu/h): About 15.2 SEER2 for split and single-packaged units.

If you want lower bills and simpler rebate conversations, aim for ENERGY STAR® tiers when possible. For packaged choices, browse Commercial Package Heat Pumps.

5) How to verify compliance on a quote (fast)

Before you sign:

• Ask for the AHRI certificate—it lists the exact SEER2/HSPF2 for the quoted match-up (outdoor + indoor model).

• Check ENERGY STAR® if you’re targeting 15.2 SEER2 tiers.

• Confirm region Southern states have specific minimums.

• Check manufacture date on the nameplate or submittal.

• Review indoor models mismatching air handlers or coils can drop efficiency below the rating.

Keep a PDF of the AHRI listing with your project file. It helps with permits, inspections, and utility programs. If the paperwork doesn’t match the installed equipment, stop and resolve it—don’t assume it’s “close enough.” Need help reading a submittal set? Reach out via Contact Us or send photos through Quote by Photo.

Replace or repair how SEER2 influences the call

If your older unit still runs but needs major work (compressor, coil, or control board), compare repair cost to operating cost over the next 5–10 years. SEER2-compliant equipment often slashes seasonal kWh, especially on long cooling seasons. Consider:

• Downtime risk (lost sales, hot tenants).

• Expected lifespan after repair vs. new warranty.

• Energy use difference between current unit and a 14.3–15.2 SEER2 option.

• Code compliance for replacements after 1/1/2023.

If ducts are leaky or undersized, replacing just the box won’t deliver the rating. Fix airflow now and you’ll feel it every bill cycle. Explore packaged swaps here: Package Units or match indoor pieces in Air Handlers.

Spec’ing a compliant rooftop or split—step-by-step

1. Confirm load (square footage, people, glass, hours).

2. Choose configuration: packaged RTU vs. split.

3. Target rating: meet the minimum SEER2 for your region; consider ENERGY STAR® 15.2 SEER2 for lower bills.

4. Match indoor/outdoor—use AHRI-listed pairings.

5. Plan airflow—verify CFM/ton, duct static pressure, and filter area.

6. Add economizer and controls where useful.

7. Select accessories (curbs, disconnects, smoke detectors, hail guards).

8. Document AHRI/ENERGY STAR® for permits.

Not sure which curb you have? Snap a few photos and use Quote by Photo. We'll help you match it.

Installation details that protect your SEER2 rating

A great unit can perform poorly if installation skips the basics. Focus on:

• Airflow: Set CFM/ton at the blower; verify static pressure.

• Refrigerant lines: Size correctly; braze with nitrogen purge; evacuate to ≤500 microns; weigh in the charge.

• Coil match: Use the AHRI-listed coil/air handler.

• Controls: Program fan profiles, staging, and economizer.

• Drainage & pitch: Keep pans and traps correct to avoid water issues.

Document readings (suction, liquid, superheat, subcooling, supply/return temperature split). That “snapshot” proves the system ran at spec on day one. Stock what you need from Accessories and Line Sets before the crane shows up.

Commissioning quick checks that prevent callbacks

Commissioning is your insurance policy:

• Verify model and serial numbers match the submittal/AHRI certificate.

• Record baseline: ambient temp, indoor wet-bulb/dry-bulb, superheat/subcooling, and ESP (external static pressure).

• Confirm controls: stage changeover, economizer operation, and setpoints.

• Test safeties: float switches, smoke detector input, and phase monitors (for three-phase).

• Airflow balance: measure supply/return; adjust taps or ECM profiles.

Save results as a one-page “startup sheet” and keep it with the AHRI certificate. If performance drifts, you’ll know exactly what changed. For packaged projects, see Commercial Package Heat Pumps.

Maintenance that keeps you compliant—ASHRAE 180 basics

SEER2 isn’t “set and forget.” ASHRAE Standard 180 outlines routine tasks that keep efficiency on track:

• Filters: size for low pressure drop; change on schedule.

• Coils: clean condenser/evaporator; bent fins cost watts.

• Belts & bearings: tension, alignment, and lubrication.

• Economizer dampers: test move/close; failed dampers waste energy.

• Electrical: tighten lugs; check contactors and capacitors.

• Set quarterly/seasonal checklists and log readings versus your startup sheet. 

If your static pressure or subcooling drifts from baseline, fix it before it snowballs. Stock upkeep items via Commercial HVAC Accessories. Questions? Our Help Center has quick answers.

Common pitfalls and easy fixes from real jobs

• Mismatched indoor coils: Always use the AHRI-listed match.

• Undersized return: High static kills airflow and efficiency. Add return area or lower MERV if needed.

• Skipped nitrogen purge: Leads to restricted lines; purge while brazing.

• Wrong charge method: Charge by weight and confirm with superheat/subcooling.

• Economizer never enabled: Program it—free cooling saves real money.

On heat pumps, verify HSPF2 requirements and outdoor sensor placement for defrost and balance point. If you’re replacing a legacy RTU, compare packaged options here: Package Units.

If you want a second set of eyes on a quote, contact us we’re happy to sanity-check it like a good neighbor would.