What to Look for When Buying a New Central HVAC System

What to Look for When Buying a New Central HVAC System

Buying a new central HVAC system is one of the largest home improvement investments you'll make—typically $12,000 to $25,000 installed in the Bay Area. Yet most homeowners know very little about what they're buying.

After installing thousands of HVAC systems across the San Francisco Bay Area, we've seen the difference between smart purchases and expensive regrets. This guide covers everything you need to know to make a confident, informed decision.

Quick Answer: Key Factors When Buying HVAC

Factor	What to Look For	Why It Matters
Proper sizing	Manual J load calculation	Wrong size = comfort problems + higher bills
Efficiency rating	SEER2 15+ for AC, AFUE 95%+ for furnace	Lower operating costs for life of system
Equipment quality	Tier 1 brands with good warranties	Reliability and long-term value
Installation quality	Licensed contractor, permit pulled	Performance depends on installation
Total cost	Itemized quote with all components	Avoid hidden costs and compare fairly

Understanding HVAC System Types

Before shopping, understand what type of system fits your home and climate.

Central Air Conditioner + Gas Furnace (Split System)

Best for: Homes with existing ductwork, colder climates

Components:

• Outdoor condenser unit (cooling)
• Indoor furnace (heating)
• Indoor evaporator coil (cooling)
• Ductwork throughout home

Pros:

• Reliable, proven technology
• Powerful heating for cold nights
• Lower upfront cost than heat pumps
• Familiar to most contractors

Cons:

• Uses natural gas (carbon emissions)
• Two separate systems to maintain
• Less efficient than heat pumps in mild climates

Bay Area fit: Good choice for inland valleys with colder winters (Walnut Creek, Concord, Livermore).

Heat Pump System

Best for: Mild climates, all-electric homes, efficiency priority

Components:

• Outdoor heat pump unit (heating AND cooling)
• Indoor air handler
• Ductwork throughout home

Pros:

• One system for heating and cooling
• 2-3x more efficient than gas furnaces
• No natural gas needed
• Qualifies for larger rebates

Cons:

• Higher upfront cost
• May struggle in extreme cold (below 25°F)
• Requires larger electrical service

Bay Area fit: Excellent for coastal areas and most of the Bay Area. Our mild climate is ideal for heat pumps.

Dual Fuel System (Heat Pump + Gas Furnace)

Best for: Maximum efficiency with backup for coldest days

Components:

• Outdoor heat pump unit
• Indoor gas furnace (backup heat)
• Indoor evaporator coil
• Ductwork throughout home

Pros:

• Uses heat pump most of the time (efficient)
• Switches to gas on coldest days (powerful)
• Best of both worlds

Cons:

• Highest upfront cost
• More complex system
• Requires gas line

Bay Area fit: Great for inland valleys where temperatures occasionally drop below 35°F.

The Most Important Factor: Proper Sizing

This is where most HVAC purchases go wrong.

An oversized system costs more, wastes energy, and creates comfort problems. An undersized system runs constantly and can't keep up on extreme days.

What Proper Sizing Looks Like

A contractor should perform a Manual J load calculation that considers:

• Square footage of your home
• Ceiling heights
• Window sizes, types, and orientations
• Insulation levels in walls, attic, floors
• Air leakage characteristics
• Number of occupants
• Kitchen and appliance heat loads
• Local climate data

This takes 30-60 minutes and may involve measuring rooms, checking insulation, and asking questions about your home.

Red Flags: Signs of Improper Sizing

Warning signs the contractor is guessing:

• Quote given after a 10-minute walkthrough
• Size based only on square footage ("1 ton per 500 sq ft")
• Same size recommendation as your old system without calculation
• No questions about insulation, windows, or home improvements

Common Sizing Mistakes in Bay Area Homes

Coastal homes (SF, Oakland, Daly City):

• Often oversized because contractors use inland climate data
• Mild temperatures mean smaller equipment works fine

Inland homes (Walnut Creek, Livermore, Antioch):

• Sometimes undersized when coastal sizing rules are applied
• Need to account for 100°F+ summer days

Older homes with upgrades:

• New windows and insulation mean old sizing is wrong
• Often oversized if upgrades aren't factored in

Understanding Efficiency Ratings

Higher efficiency = lower monthly bills for the life of the system. Here's what the numbers mean.

Air Conditioner and Heat Pump Ratings

SEER2 (Seasonal Energy Efficiency Ratio 2)

• Measures cooling efficiency
• Higher = more efficient
• Minimum legal in California: 14.3 SEER2
• Good: 15-17 SEER2
• Excellent: 18-21 SEER2
• Premium: 22+ SEER2

HSPF2 (Heating Seasonal Performance Factor 2)

• Measures heat pump heating efficiency
• Higher = more efficient
• Minimum legal: 7.5 HSPF2
• Good: 8-9 HSPF2
• Excellent: 10+ HSPF2

Furnace Ratings

AFUE (Annual Fuel Utilization Efficiency)

• Percentage of fuel converted to heat
• Higher = less fuel wasted
• Standard efficiency: 80% AFUE
• High efficiency: 90-95% AFUE
• Ultra-high efficiency: 96-98% AFUE

Is Higher Efficiency Worth the Cost?

Efficiency Level	Upfront Cost	Annual Savings	Payback Period
Standard (14 SEER2, 80% AFUE)	Baseline	Baseline	N/A
Good (16 SEER2, 95% AFUE)	+$1,500-2,500	$200-400/year	5-8 years
Premium (20 SEER2, 97% AFUE)	+$4,000-6,000	$400-600/year	8-12 years

Bay Area recommendation: 16+ SEER2 and 95%+ AFUE offer the best balance of cost and savings for our climate.

Choosing the Right Brand

Not all HVAC brands are equal. Here's how they break down.

Tier 1: Premium Brands

Carrier, Lennox, Trane, American Standard

• Best warranties (10-12 years parts, lifetime heat exchanger)
• Highest build quality
• Most advanced features
• Price: $$$$

Tier 2: Quality Mid-Range Brands

Bryant, Rheem, Ruud, Goodman (Daikin)

• Solid warranties (10 years parts)
• Reliable performance
• Good value for money
• Price: $$$

Tier 3: Budget Brands

Payne, Comfortmaker, various off-brands

• Shorter warranties (5-10 years)
• Basic features
• Lower upfront cost
• Price: $$

What Matters More Than Brand

Installation quality matters MORE than brand.

A mid-tier system installed correctly will outperform a premium system installed poorly. Focus on:

1. Contractor reputation and reviews
2. Proper sizing and design
3. Quality installation practices
4. Good warranty terms

Brand Features to Consider

Variable-speed or two-stage systems:

• Quieter operation
• Better humidity control
• More even temperatures
• Higher efficiency
• Worth the upgrade for most homes

Single-stage systems:

• Lower upfront cost
• Simpler to repair
• Adequate for mild climates
• Good budget choice

What's Included in a Complete Installation

A proper HVAC installation includes more than just the equipment. Make sure quotes cover:

Equipment

• Outdoor unit (condenser, heat pump, or package unit)
• Indoor unit (furnace, air handler, or fan coil)
• Evaporator coil (for AC systems)
• Thermostat (smart thermostat recommended)
• Refrigerant lines
• Condensate drain and pump (if needed)

Installation Components

• New disconnect box and whip
• Concrete pad for outdoor unit
• Ductwork modifications (if needed)
• New supply and return plenums
• Refrigerant line set
• Electrical wiring and connections
• Gas line connection (furnaces)

Labor and Services

• Removal and disposal of old equipment
• Permit and inspections
• Manual J load calculation
• System commissioning and testing
• Homeowner instruction

What's Often Missing From Low Quotes

Watch for these items NOT included:

• Permit fees ($400-$1,300)
• Ductwork repair or replacement
• Electrical panel upgrade
• New thermostat
• Concrete pad
• Crane rental (difficult access)
• Asbestos abatement (older homes)

Always get itemized quotes so you can compare apples to apples.

Questions to Ask Every Contractor

Ask these questions before signing anything.

About Sizing and Design

1. "How will you determine the correct size system for my home?"

   • Good answer: Manual J load calculation
   • Red flag: "Based on square footage"

2. "Can I see the load calculation report?"

   • Good answer: "Yes, I'll provide a copy"
   • Red flag: "We don't do that" or reluctance

3. "What size system are you recommending and why?"

   • Should explain reasoning based on your home's specific needs

About Equipment

4. "What brand and model are you quoting?"

   • Get specific model numbers, not just "Carrier" or "Lennox"

5. "Why do you recommend this particular equipment?"

   • Should relate to your needs, not just what's in stock

6. "What's the warranty coverage?"

   • Get details: parts, labor, heat exchanger, compressor

About Installation

7. "Will you pull a permit for this work?"

   • Required answer: "Yes"
   • Red flag: "You don't really need one"

8. "Who will actually do the installation?"

   • Know if it's their employees or subcontractors

9. "How long will the installation take?"

   • Furnace only: 1 day
   • Furnace + AC + coil OR heat pump + air handler: 2 days when done properly
   • New ductwork: add 1-2 additional days

About Cost

10. "Is this quote itemized?"

    • You should see equipment, labor, permits, materials listed separately

11. "What's NOT included in this quote?"

    • Forces disclosure of potential add-ons

12. "What financing options do you offer?"

    • Many offer 0% for 12-18 months or low-rate options

Red Flags to Avoid

Contractor Red Flags

• No license displayed: Check CSLB.ca.gov
• No permit offered: Major red flag for quality
• High-pressure sales: "Price only good today"
• Much lower than other quotes: Corners will be cut
• No references: Can't verify work quality
• Insists on cash only: Avoid paper trail
• No written contract: Protects neither party

Quote Red Flags

• Round number quotes: Suggests guessing, not calculating
• No equipment model numbers: Can't verify what you're getting
• "Estimated" pricing: Should be firm after home visit
• No warranty information: What are they hiding?
• Missing permit line item: May not be pulling permits

Installation Red Flags

• Starts without permit: Illegal and unprotected
• Rushes through in 3-4 hours: Quality takes time
• Doesn't test system thoroughly: Should measure airflow, temperatures
• Won't explain operation: Good contractors teach you the system

Bay Area Rebates and Incentives (2026)

Rebate programs change frequently. Here's the current status:

HEEHRA Rebates (Income-Qualified)

Home Electrification and Appliance Rebates:

• Up to $8,000 for heat pump installation
• Available to households under 150% Area Median Income
• Applied at point of sale (no waiting for tax refund)
• Check current HEEHRA availability

Programs No Longer Available

The following programs are no longer available as of 2026:

• Federal tax credits: The 25C Energy Efficient Home Improvement Credit for HVAC equipment has expired
• BayREN Home+: Program ended April 2024
• PG&E rebates: Currently no HVAC equipment rebates available
• TECH Clean California: Fully reserved since January 2025

What This Means for You

Without federal tax credits and utility rebates, focus on:

1. Long-term energy savings - High-efficiency systems still pay for themselves over time
2. HEEHRA if eligible - Income-qualified households can still receive significant rebates
3. Financing options - Many contractors offer 0% financing for 12-18 months
4. Right-sizing - Proper sizing reduces equipment cost and energy bills

Note: Rebate programs change frequently. Ask your contractor about current programs and check our rebates page for updates.

What to Expect: Timeline and Process

Getting Quotes (1-2 Weeks)

1. Research contractors (reviews, licenses)
2. Schedule 2-4 in-home estimates
3. Each visit takes 45-90 minutes
4. Receive written quotes within 2-5 days

Making a Decision (3-7 Days)

1. Compare quotes (itemized breakdown)
2. Check references
3. Verify license and insurance
4. Sign contract and schedule installation

Permit Process (3-10 Days)

1. Contractor pulls permit
2. City reviews and approves
3. Some cities same-day, others take longer

Installation Day(s)

Furnace Only (1 Day):

• Remove old furnace (1-2 hours)
• Install new furnace (3-4 hours)
• Connect gas and electrical
• System testing and homeowner walkthrough

Furnace + AC + Coil OR Heat Pump + Air Handler (2 Days):

Day 1:

• Remove old equipment
• Install outdoor unit and indoor equipment
• Run refrigerant lines
• Connect electrical and gas (if applicable)

Day 2:

• Charge refrigerant system
• Complete all connections
• Comprehensive system testing
• Final inspection and homeowner walkthrough

With New Ductwork: Add 1-2 additional days

After Installation

• Permit inspection (scheduled within 1-2 weeks)
• Register warranty with manufacturer
• Schedule first maintenance (6-12 months)

Bay Area Cost Guide (2026)

System Type	Good Quality	Premium Quality
Central AC + 80% Furnace	$10,000-14,000	$14,000-18,000
Central AC + 96% Furnace	$12,000-16,000	$16,000-22,000
Heat Pump + Air Handler	$14,000-18,000	$18,000-25,000
Dual Fuel (HP + Furnace)	$16,000-22,000	$22,000-30,000

Prices include: Equipment, installation, permits, basic thermostat, standard ductwork connections.

May add cost: Ductwork replacement ($3,000-8,000), electrical upgrade ($1,500-4,000), difficult access, asbestos removal.

Final Checklist Before Signing

Use this checklist before committing:

Contractor Verification:

• Valid California contractor's license (check CSLB.ca.gov)
• Proof of liability insurance
• Workers' compensation insurance
• Good reviews (Google, Yelp, BBB)
• At least 3 references you can call

Quote Completeness:

• Specific equipment brand and model numbers
• All components listed and priced
• Installation labor itemized
• Permit costs included
• Removal and disposal included
• Warranty terms clearly stated
• Total price is firm (not estimated)

Technical Requirements:

• Manual J load calculation provided
• Equipment size matches calculation
• Efficiency ratings meet your goals
• Ductwork assessment completed

Contract Terms:

• Written contract provided
• Start and completion dates
• Payment schedule (avoid large deposits)
• Change order process defined
• Cleanup and disposal responsibility

Ready to Get Started?

Choosing a new HVAC system doesn't have to be overwhelming. Focus on:

1. Right size - Insist on a Manual J calculation
2. Right efficiency - Match your budget and goals
3. Right contractor - Licensed, insured, well-reviewed
4. Right price - Fair market rate with everything included

Get a free estimate from Galaxy Heating & Air Conditioning:

Call: (925) 578-3293

What we offer:

• Free in-home consultation and load calculation
• Honest recommendations (not sales pressure)
• Upfront, itemized pricing
• Quality installation by our own team
• 100% satisfaction guarantee

Serving the entire Bay Area:

• Contra Costa County
• Alameda County
• San Francisco
• San Mateo County

---

Galaxy Heating & Air Conditioning
Licensed CSLB #1076868 | NATE Certified | EPA Certified

Prices reflect Bay Area market rates as of January 2026. Actual costs vary based on home size, equipment selection, installation complexity, and current material costs. Rebate programs subject to change and funding availability.