Follow This Old House online:

We may be compensated if you purchase through links on our website. Our team is committed to delivering honest, objective, and independent reviews on home products and services.

Professional technician standing on a ladder in the room repairing or installing air conditioner.

Advertiser Disclosure

Our editorial team is committed to creating independent and objective content focused on helping our readers make informed decisions. To help support these efforts we receive compensation from companies that advertise with us.

The compensation we receive from these companies may impact how and where products appear on this site. This compensation does not influence the recommendations or advice our editorial team provides within our content. We do not include all companies, products or offers that may be available.

How Much Does an Air Conditioner Cost for a 3,600-Square-Foot Home?

On average, replacing an air conditioning system in a 3,600-square-foot home costs around $17,389, with a typical low-end price of $12,988 and a high-end price of $24,970 for a 14.3 SEER2 split system.

Join the 4,492 people who received a free, no obligation quote in the last 30 days

Invalid Zip Code
Get Your Estimate
Enter details in under 3 minutes
Clicking “Get Your Estimate” submits your data to All Star Pros, which will process your data in accordance with the All Star Pros Privacy Policy.
Ad Disclaimer
Written by
Alexis Carthan
Written by
Alexis Carthan
Updated 06/02/2025

On average, replacing an air conditioning system in a 3,600-square-foot home costs around $17,389, with a typical low-end price of $12,988 and a high-end price of $24,970 for a 14.3 SEER2 split system (including an AC and a gas furnace). Your final cost depends on several factors, including the type of system you choose, its efficiency rating, and the complexity of the installation.

Get Estimates from HVAC Experts in Your Area

Compare quotes from top-rated local pros

Invalid Zip Code
Get Your Estimate

Enter details in under 3 minutes

Clicking “Get Your Estimate” submits your data to All Star Pros, which will process your data in accordance with the All Star Pros Privacy Policy.
Ad Disclaimer

HVAC Replacement Costs by System Type

For a large 3,600-square-foot home, selecting the right HVAC system is crucial. Homes of this size typically require either one large system or multiple smaller systems to maintain comfortable temperatures throughout.

A traditional split system, which combines an AC unit with a gas furnace, provides powerful cooling alongside efficient heating. For homes of your size, this requires either a high-capacity system (7-8 tons) or multiple smaller systems, each zoned for a different area. Electric furnace combinations pair an air conditioner with an electric furnace. While eliminating the need for natural gas service, they typically have higher operating costs during heating seasons.

Heat pump systems handle both heating and cooling using a single outdoor unit and indoor air handler. For a home of your size, higher-capacity heat pumps can maintain comfortable conditions year-round in many climates, offering improved energy efficiency. Dual fuel systems combine a heat pump with a gas furnace backup, switching automatically between them based on outdoor temperatures. For a large home with substantial conditioning requirements, this adaptability can significantly reduce operating costs.

For a 3,600-square-foot home, here’s what you can expect to pay across different system types with low (12.4 SEER2), high (16.1 SEER2), and average (14.3 SEER2) price points:

System TypeLow CostHigh CostAverage Cost
AC and gas furnace$11,960$30,951$17,389
AC and electric furnace$10,745$27,674$12,300
Heat pump and air handler$11,810$30,545$17,156
Dual fuel system$15,197$39,681$22,398
Air conditioner only$11,055$28,509$15,988

HVAC Replacement Cost Breakdown

For a 3,600-square-foot home, equipment costs constitute the largest portion of your investment, accounting for approximately 65%–70% of the total. This includes the outdoor condenser unit, indoor air handler or furnace, evaporator coil, and associated components.

Labor costs reflect the increased complexity and time requirements associated with these projects. Professional installation typically requires 10-14 hours for a standard replacement, with additional time necessary for complex installations or multiple systems.

Permit costs ensure your installation complies with local building codes and safety regulations. Most jurisdictions require inspections to verify proper installation and code compliance.

Here’s a breakdown of these cost components based on a 14.3 SEER2 AC and gas furnace system:

Cost ComponentEstimated Cost
Equipment (unit)$9,870–$17,866
Labor$3,118–$7,104
Total$12,988–$24,970

Additional Charges for an HVAC Installation

Smart thermostats with multi-sensor capabilities utilize temperature readings from multiple locations throughout your home, rather than relying on a single measurement point. Many advanced models also incorporate usage pattern learning and remote access capabilities.

Zoning systems divide your home into separately controlled areas, each with its own independent temperature setting. For a 3,600-square-foot home, zoning becomes essential. While adding $3,400–$5,100 to your installation cost, zoning systems can reduce energy consumption by 20%–30%.

Ductwork modification or replacement may be necessary to ensure proper airflow distribution. A professional assessment may reveal the need for larger main trunks, additional returns, or strategic damper placement to balance airflow.

Here are the average prices of these additional charges:

Additional ChargeEstimated Cost
Thermostat$39–$217
Ductwork Replacement$3,000–$6,000
Permits$250–$400

How Do I Determine the Tonnage or SEER2 Rating?

For a 3,600-square-foot home, proper system sizing is crucial. Tonnage refers to your system’s cooling capacity, with one ton equaling 12,000 BTUs per hour. For a home of your size, you’ll typically need either one larger 8–9 ton system or multiple smaller systems with a combined capacity of 8–9 tons.

A comprehensive load calculation conducted by your HVAC contractor is essential. The industry-standard Manual J methodology evaluates numerous factors, including your home’s insulation levels, window efficiency, ceiling heights, orientation, local climate conditions, and typical occupancy patterns.

For a 3,600-square-foot home, the energy consumption difference between a minimum-efficiency system and a high-efficiency model becomes particularly significant due to the substantial cooling load. While 12.4–15.2 SEER2 units offer lower initial costs, the operating savings from 15.2+ SEER2 systems can amount to hundreds of dollars annually.

The table below summarizes costs for an AC and gas furnace system in a 3,600 sq ft home across various SEER2 ratings:

SEER2 RatingLow CostAverage CostHigh Cost
12.4$11,960$15,964$23,109
13.4$12,351$16,505$23,815
14.3$12,988$17,389$24,970
15.2$12,919$17,293$24,844
16.1$16,293$21,969$30,951

Note that SEER2 requirements vary by region. For example, the Southeast and Southwest regions require a minimum of 14.3 SEER2 for new central air conditioners. Lower-rated units, such as those with a 12.4 SEER2, are no longer widely available due to updated federal efficiency standards. Your contractor can help you ensure your unit meets requirements.


How Does My Location Affect Cost?

Regional labor rates vary significantly across the country, with metropolitan areas and coastal regions generally commanding higher rates. Installation complexity increases with home size as technicians navigate larger duct systems and more complex zoning requirements.

Climate directly impacts system selection and sizing. Southern regions often require larger cooling capacity with enhanced humidity control, while northern areas might need systems with more robust heating capabilities.

Local building codes and energy efficiency requirements vary between jurisdictions. Some areas have adopted stringent energy codes that mandate minimum efficiency levels exceeding federal standards.

The highest labor costs typically come from the Northeast and Hawaii, ranging as high as $7,104 for a 3,600-square-foot home. Southern states generally offer more affordable installation rates, with some areas starting around $3,118 for labor.

Editor’s note: Although this article discusses SEER2 ratings in the context of AC and gas furnace split systems, SEER2 applies only to the air conditioning portion. SEER2 measures cooling efficiency and does not apply to the heating performance of gas furnaces.


FAQs

When should I consider a two-stage or variable-speed compressor?

In a 3,600 sq. ft. home, single-stage compressors often cause uneven temperatures. Two-stage systems enhance comfort by operating at 65% or 100%, while variable-speed compressors adjust from 25% to 100% in small increments, maintaining temperatures within ±0.5°F and reducing energy use by up to 40%. They also remove up to 4x more humidity and run more quietly. Though they cost $1,800–$3,200 more, the typical payback is 3–5 years from energy savings and enhanced comfort across your entire home.

How do equipment warranties work for homes with multiple systems?

Each HVAC system in your home has its own warranty. Manufacturer parts warranties usually last 5–10 years and must be registered within 60–90 days of installation. Coverage isn’t transferable between units. If one system is replaced, only the new unit’s warranty resets. Labor warranties from installers are typically 1–2 years per system. Evaluate extended warranties individually, especially if your systems differ in technology or usage. Always request detailed documentation for each system.

What considerations should I make for proper load distribution across multiple units?

In large homes with multiple HVAC units, zones should follow natural divisions, such as floors or wings. Each system must be sized for its specific zone, taking into account factors such as sun exposure, insulation, and adjacent spaces. Use separate thermostats placed away from heat sources or direct sunlight. Thoughtful zoning and return air placement prevent imbalances, ensuring each system operates efficiently without overworking.

What energy-efficiency upgrades should I consider alongside my HVAC replacement?

When replacing your HVAC system, consider making complementary energy efficiency upgrades to enhance comfort and lower operating costs. Upgrading attic insulation to an R-value of 49 or higher typically costs between $1,800 and $3,500 and can reduce your HVAC load by 15-20%, which may allow for a smaller system.

Additionally, professional air sealing, ranging from $800 to $1,600, can prevent up to 30% of conditioned air from escaping your home. Installing a radiant barrier in the attic, which costs about $1 to $2 per square foot, reflects heat away from your home and can decrease the cooling load by 10-15% during the summer months.

Using ceiling fans in frequently occupied rooms, which cost between $150 and $350 each, creates a wind-chill effect, permitting you to raise your thermostat setting by 4°F without sacrificing comfort. Smart window treatments, costing between $1,500 and $4,000 for an entire home, can reduce solar heat gain by as much as 45% when closed.

These upgrades often deliver better value than simply opting for a larger HVAC system, and many improvements qualify for additional tax incentives or rebates.


How We Get Our HVAC Cost Data

Replacing an HVAC system is a large investment. Throughout this article, we estimated what it would cost to replace an HVAC system in a 3,600-square-foot home. Keep in mind: These are estimates intended to help you understand what a project like this might cost. You should get quotes from at least two companies to understand the true costs in your area.

We collected unit prices and the average cost of labor to calculate a total estimated price to replace an HVAC system in a 3,600-square-foot home. For unit costs, we collected wholesale prices for air condensers, electric furnaces, gas furnaces, evaporator coils, heat pumps, and air handlers from three sources, including: AC Direct, HVACDirect.com, and Buy Comfort Direct. We calculated prices for the total system using various combinations of unit costs. We also added an estimated retail markup. For labor, we researched the average time it takes to replace an HVAC system and multiplied this by the average cost of labor.

To share feedback or ask a question about this article, send a note to our team at reviews@thisoldhousereviews.com.