Seasonal tune-up and full diagnostic on your Carrier, Trane, or Goodman system - readings shown to you before any repair is proposed
Diagnosis first, numbers second - you approve the repair price before a single part goes in.
Before
After
Before
After
Before
AfterFast, Reliable AC Installation Across Marietta
New AC installation in Marietta typically runs $3,500-$7,500 for a complete system, and most jobs are scheduled within a few business days after your free in-home estimate. Our AC Installation team at Coldharbour Heating & Air has been sizing, designing, and installing cooling systems for Marietta’s specific housing stock since 2003, and we know the difference between a proper load calculation and a box swap that’ll leave you sweating by July.
We dispatch from our Atlanta office, but our crews live and work in Cobb County. That means we understand why a 1979 split-level off Sandy Plains Road needs a different approach than a new build in West Cobb. When you call (817) 402-2972, a live person answers, day or night. We’ll set a firm arrival window, measure every room, inspect your ductwork and electrical panel, and hand you a written fixed price before any work begins.
Why Coldharbour Heating & Air Is Marietta’s Preferred AC Installation Company
Marietta homeowners have long memories. They remember the company that showed up three hours late, or the installer who quoted one price and charged another at the door. We don’t work that way. Coldharbour operates under The Kingswell Way: say the price before the work starts, show up in the window promised, leave the place cleaner than found, put the guarantee in writing, and come back if it fails.
Our 365-Day Done Right Promise means every repair comes with a written guarantee valid for a full year. If it fails, we return and correct the work at no charge. No argument, no additional invoice. That guarantee is written down before our technician leaves your driveway.
Our technicians are background-checked, uniformed, and trained on nine major residential HVAC brands including Trane, Lennox, Goodman, and Rheem. When we install a new system in your Marietta home, the technician who shows up can handle whatever brand you choose, and we stock common parts locally so you’re not waiting on a warehouse shipment.
Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail trees, no after-hours runaround.
Ductless Mini Split Installation in Marietta
Ductless Mini Split Installation in Marietta solves a problem we see constantly in the historic neighborhoods around Marietta Square and in those 1970s ranches with no attic space for conventional ductwork. A mini split uses an outdoor condenser connected to one or more indoor wall or ceiling units by a small refrigerant line, so you get room-by-room cooling without tearing open walls or fighting a crawlspace that hasn’t been touched since the Carter administration.
Most Marietta homeowners call us about mini splits for three reasons: they’re adding a bonus room over the garage in East Cobb, their historic home near Whitlock Avenue has no duct infrastructure, or they’ve given up on the single window unit that never quite cools the master bedroom. A typical ductless installation in Marietta falls within our $3,500-$7,500 range depending on how many indoor zones you need.
When a Mini Split Beats Central Air
We installed a three-zone Mitsubishi system in a 1920s Craftsman near Kennesaw Avenue last spring. The homeowner had been through three summers with a portable AC that cost $400 and sounded like a helicopter. Now the kitchen, living room, and bedroom each have their own temperature control, and the electric bill dropped because she’s not cooling rooms she isn’t using.
Electrical Prep for Older Homes
Marietta’s pre-WWII homes often have 100-amp panels with no spare breaker slots. We check this before quoting. If your panel needs a subpanel or service upgrade to handle the mini split’s inverter, we’ll tell you upfront and coordinate the electrical work so you’re not caught off guard on install day.
AC Replacement in Marietta
AC Replacement in Marietta is rarely as simple as pulling out the old condenser and sliding in a new one. In this market, we’re usually replacing systems installed 15-20 years ago in homes built 40-50 years ago, and the house has changed. Additions, new insulation, replaced windows, even mature trees that now shade the west side, all of it affects what size system you actually need.
We perform a Manual J load calculation on every replacement. That means measuring square footage, counting windows, checking insulation depth, and testing duct leakage. The result is a system sized for your home as it exists today, not as it was in 1987. AC replacement in Marietta typically runs $3,500-$7,500 for a full system, with financing and rebate paperwork handled in-house.
The Ductwork Reality Check
We replaced an aging system in a 1979 brick split-level off Sandy Plains Road in East Marietta where the original flex duct ran through a 135°F attic and leaked at every delaminated collar, so we performed a room-by-room load calculation, sealed and re-routed ductwork, added a return for the upper bedrooms, and set the new Carrier condenser with a proper refrigerant charge and thermostat calibration. The homeowner’s upstairs bedroom finally dropped to 72°F on a 96°F afternoon, and the static pressure stayed within spec instead of choking the blower motor.
Why Like-for-Like Swaps Fail
A “same tonnage” replacement in a 1970s Marietta ranch often disappoints because the original system was probably oversized to begin with, and the ductwork has deteriorated. You end up with a new compressor fighting the same leaky flex, short-cycling on and off, never dehumidifying properly, and dying young. We won’t sell you that install.
Trusted Brands We Service in Marietta
We install and service Trane, Lennox, Goodman, and Rheem systems, and our technicians carry factory training on all four. For Marietta homeowners, that means we stock common components at our Atlanta warehouse, not halfway across the state. When your new Lennox needs a proprietary control board or your Rheem heat pump requires a specific TXV, we don’t wait three days. We pull it and drive it to your door. That local parts availability matters in July, when a delay isn’t an inconvenience, it’s a week of sleeping downstairs.
Common AC Installation Problems We See in Marietta Homes
- Original flex duct delamination in 1970s-80s ranches. Marietta’s Lockheed-era subdivisions were built with flex duct that degrades after 25-30 years in 130°F attics. We test every foot with a duct blaster and show you the leakage numbers before we quote replacement.
- Single-zone systems in split-level homes. That half-level design in East Marietta and Cobb County build-outs means one thermostat can’t satisfy both the sunken living area and the upper bedrooms. We address this with zoning or properly designed duct modifications, not a bigger unit.
- Undersized electrical panels. Many Marietta homes still run on 100-amp service with fuse boxes or early breaker panels. A modern heat pump or high-SEER2 central air can demand 30-50 amps on its own. We inspect your panel before quoting and flag any upgrade needs.
- Attic air-sealing gaps. In Marietta’s humidity, a leaky attic floor pulls moist outdoor air into your conditioned space all summer. We seal the envelope before setting the new system so you’re not paying to dehumidify Cobb County’s atmosphere.
Pricing for AC Installation in Marietta, GA
Most complete AC installations in Marietta run $3,500-$7,500, including equipment, labor, refrigerant, electrical connections, and basic duct modifications. What moves you within that range? System size measured in tons, SEER2 efficiency rating, single-stage versus variable-speed compressor, and whether your existing ductwork passes our leakage test or needs replacement.
| Service | Typical Range in Marietta |
|---|---|
| AC Installation (complete system) | $3,500 - $7,500 |
| AC Repair | $150 - $650 |
| Furnace Repair | $150 - $700 |
| Annual Tune-Up | $80 - $200 |
We don’t quote over the phone for installation work. Every home in Marietta is different, especially with the split-level and ranch stock we’re working in. Our in-home estimate is free, takes about 45 minutes, and ends with a written fixed price that doesn’t change when the crew arrives. Call (817) 402-2972 to schedule.
We Also Serve Cities Near Marietta
Our crews work throughout Cobb County and beyond. If you’re in Marietta proper, Smyrna, Kennesaw, Powder Springs, or the Atlanta side of the Perimeter, we cover your area with the same written pricing, firm arrival windows, and 365-Day Done Right Promise. Dispatch and scheduling are coordinated from our Atlanta office, with local technicians serving each community.
Serving Marietta, GA - Our Local Coverage Area
We’re based in the Marietta area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About AC Installation in Marietta
Because the original system was likely oversized, the flex duct has delaminated in 130°F attics, and the house has probably gained insulation or window upgrades that changed its load. A like-for-like swap ignores all of this, so you get short-cycling, poor humidity control, and premature equipment failure. We perform a fresh load calculation and duct test on every replacement. Call (817) 402-2972 for a free estimate.
Most split-levels in the 1970s East Marietta/Cobb build-out need either zoning or significant duct redesign, because a single system cannot overcome the static pressure between the sunken living area and upper bedrooms. We’ve solved this with both approaches, and we’ll show you which fits your floor plan and budget. Call (817) 402-2972 to schedule an evaluation.
Many Marietta homes from the 1960s-80s still have 100-amp panels with no spare breakers, aluminum branch wiring, or fuse boxes that can’t handle a modern system’s inrush current. We inspect your panel during the estimate and coordinate any electrical upgrades before installation day so you’re not surprised by a mid-project stop-work. Call (817) 402-2972 to book your free assessment.
SEER2 is the updated efficiency standard that better reflects real-world conditions, including the high static pressure and humidity loads common in Marietta’s climate. A higher SEER2 rating means longer run cycles at lower speed, which pulls more moisture from the air. In Cobb County’s low-to-mid-70s°F dew points, that dehumidification matters as much as temperature drop. Call (817) 402-2972 to compare SEER2 options.
Homes near Whitlock Avenue and the historic square often have 18-inch crawlspaces with balloon-frame construction and no existing duct infrastructure. We use low-profile duct systems, mini splits, or carefully routed high-velocity options that fit the space without altering historic character. Every install is custom-designed after we measure and photograph the conditions. Call (817) 402-2972 for a free in-home evaluation.
Written by Victor Mancini, Owner at Coldharbour Heating & Air, serving Marietta and surrounding communities since 2003.