How to compare AC estimates from different contractors

Why AC estimates vary so much

If you have three quotes for the same air conditioner and the prices are far apart, you are not alone. The difference often comes from what is (and isn’t) included, how the system is sized, the quality of parts and labor, and whether permits and code requirements are covered. This guide shows how to compare AC estimates the right way, minimize surprises, and protect your home, budget, and warranty.

Important safety note: installing or modifying HVAC involves high voltage, refrigerants, structural loads, and code compliance. DIY work can be unsafe, may void warranties, and—per many insurance policies—unpermitted or unlicensed work can lead to denied claims. Always verify licensing and permitting requirements in your area.

Make it apples-to-apples

Ask each contractor to price the same scope. Use this AC estimate checklist to line up details:

• System type and capacity: central AC or heat pump, tonnage, and model numbers for indoor and outdoor units.
• Load calculation: written Manual J and Manual S (and Manual D if ducts are modified) with design temperatures and airflow targets.
• Efficiency: SEER2, EER2, and HSPF2 (for heat pumps). Note expected comfort features (staging or inverter) and noise ratings.
• Ductwork scope: new vs. reuse, sizing (Manual D), sealing, insulation, and measured duct leakage target with HERS test if required.
• Electrical: breaker size, dedicated circuits, disconnect, surge protection, and any panel upgrades.
• Refrigerant line-set: size, length, rerouting, pressure test, evacuation, and refrigerant recovery.
• Condensate: gravity drain vs. pump, cleanout, safety switch, and termination point.
• Controls and IAQ: thermostat model, zoning, filtration (MERV-13 or HEPA), UV or ERV/HRV options.
• Mounting and logistics: pad or roof curb, seismic strapping, crane, attic/roof access, and debris disposal.
• Permits and code: mechanical/electrical permits, California Title 24 compliance, and HERS verification where applicable.
• Startup and verification: commissioning checklist with static pressure, airflow, refrigerant charge, and delivered capacity readings.
• Warranty and service: parts warranty length, labor warranty length, and what routine maintenance is required to keep coverage.

Equipment and efficiency choices

Bigger is not better. Oversizing can cause short cycling, uneven temperatures, and humidity problems. A proper Manual J load calculation should drive capacity, not a rule of thumb or “same size as before.” Compare models by SEER2 and EER2, but also by comfort features such as variable speed, low-sound operation, and dehumidification control.

Brand matters less than design and installation quality. What matters most is that the system is right-sized, ducts are correctly designed, and commissioning is thorough. At #1 AC Guys, our engineers are trained at manufacturer facilities of Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China), which helps us navigate complex residential and commercial systems.

Labor, workmanship, and warranties

Two bids can use similar equipment, yet the labor approach can be very different. Ask about duct remediation, line-set replacement vs. flush, brazing with nitrogen purge, pressure testing, and evacuation targets. Compare labor warranty terms in writing. Confirm the manufacturer parts warranty and any registration requirements.

Permits, code, and insurance

In California, many replacements trigger Title 24 and may require a HERS test for duct leakage, airflow, and refrigerant charge. Verify that the contractor pulls the permits and includes fees. Many insurers and home warranties require licensed, permitted work; otherwise, claims for damage can be denied. When comparing HVAC quotes, ensure compliance is explicitly included, not “if needed” or left to the homeowner.

Indoor air quality and health

Comfort and efficiency are only part of the picture. Filtration (MERV-13 or higher), sealed ducts, and balanced ventilation (ERV/HRV) can improve indoor air quality, especially during wildfire season. Our mission at #1 AC Guys is healthy air at home for a healthy life, and a well-specified air conditioner estimate should address IAQ upfront.

Timeline, logistics, and safety

• Project schedule: estimated start date, duration, and inspection timing.
• Site protection: floor and attic protection, cleanup, and old equipment disposal fees.
• Safety: lockout/tagout, fall protection on roofs, and refrigerant handling certifications.

Unqualified work risks leaks, electrical hazards, and structural damage. Many of these tasks are not DIY-friendly and can be dangerous.

Price breakdown and value

Ask for a clear breakdown: equipment, materials, permits, labor, and any allowances. Clarify what counts as a change order. Note any rebates (e.g., utility or TECH Clean California), but verify eligibility and paperwork responsibilities. If financing is offered, review APR, fees, and prepayment terms. Document everything in the final contract.

Red flags and smart questions

• License and insurance numbers not provided on the proposal.
• No Manual J/S/D or refusal to pull permits.
• Very low bid with vague scope or no commissioning steps.
• Unwilling to list model numbers, SEER2 ratings, or warranty terms.

1. Can I see the load calculation and duct design?
2. What is included in commissioning and HERS test?
3. What are the exact labor and parts warranty terms?
4. Which items could trigger a change order?

Service area in Southern California

#1 AC Guys is a family-run, fourth-generation team serving Los Angeles County and nearby areas including Orange County, Ventura County, and Western Riverside County. Common cities we visit include Los Angeles, Long Beach, Pasadena, Santa Monica, Glendale, Burbank, Anaheim, Irvine, Santa Ana, Costa Mesa, Ventura, Oxnard, Thousand Oaks, Riverside, Corona, and Temecula.

Who we are

#1 AC Guys is a family business in Southern California with 80+ years in engineering across four generations. We specialize in residential and commercial work, especially large and complex projects. Our engineers have hands-on training with Fujitsu, Mitsubishi Electric, Midea, Gree, and Haier. Our purpose is simple: healthier indoor air, reliable comfort, and systems that meet code from day one.

Bottom line

To fairly compare AC estimates, lock the scope, demand a proper Manual J/S/D, confirm SEER2 and model numbers, require permits and HERS, and insist on written commissioning and warranties. That turns a confusing stack of quotes into a clear decision grounded in safety, code compliance, and long-term value.