Installed July 24, 2025 · Summerfield, San Antonio · $15,292.55 before rebate
Updated: October 21, 2026
Summary. Atlas AC Repair replaced a working, 28-year-old (1997) Carrier 4-ton R-22 system in a 2,107 sq ft Summerfield, San Antonio home with a 4-ton Carrier Infinity variable-speed air conditioner (19 SEER2), a Carrier Infinity 80 two-stage gas furnace, a new coil and an Infinity System Control. The one-day install on July 24, 2025 cost $15,292.55, or $14,392.55 after a $900 CPS Energy rebate, and was financed through Soarion Finance. A September 2025 follow-up redirected more airflow to a warm upstairs bedroom, and the cooling savings below are estimated, not measured.
Key facts
| Item | Details |
|---|---|
| Neighborhood and ZIP | Summerfield, San Antonio, TX 78231 |
| Home size | 2,107 sq ft (load report and job records), 3 bedrooms, built 1997 |
| Old equipment | Carrier 38BRC 4-ton AC, R-22, made 1997 (28 years old at replacement), still working; ADP (Advanced Distributor Products) CEH4821D75 coil, used on the R-22 system; Carrier gas furnace (model not recorded; tag not legible); Honeywell thermostat |
| New equipment | Carrier Infinity 26VNA148W003 AC (R-454B), Carrier Infinity 80 58TN0B090C21--20 gas furnace, Carrier CVAMA4921XMA coil, Carrier Infinity System Control SYSTXCCITC01-C |
| Tonnage | 4 tons old, 4 tons new |
| Efficiency | New: 19 SEER2, 11 EER2 (AHRI 215698378). Old: Carrier's 12.0 SEER rating for the 38BRC with a matched coil, about 11.40 SEER2 after conversion (old system was rated before SEER2 existed); this system used an ADP coil, so its actual rating isn't known |
| Heat load result | Building cooling load 43,726 BTU/h (40,568 sensible, 3,158 latent). Required equipment capacity at 0.9 SHR: 45,075 BTU/h, or 3.76 tons. Heating load 28,143 BTU/h. Design 101°F summer and 45°F winter outdoor, 72°F indoor; 15% duct loss and gain |
| Price | $15,292.55 installed. Price band: Atlas's published figure for a 4-ton variable-speed system is $15,992, and its Carrier Infinity cost guide lists 26VNA1 gas systems at $13,996 to $17,548 depending on tonnage (Carrier Infinity cost guide). |
| Install time | One day, about 7 hours 50 minutes on site |
| Warranty | Carrier 10-year registered parts warranty (to July 24, 2035); furnace heat exchanger to July 24, 2065; Atlas 2-year labor warranty |
| CPS Energy rebate | A $900 CPS Energy rebate was applied for on August 7, 2025, and the homeowner received it as a credit on their electric bill about a month later. Net cost after the rebate: $14,392.55 |
| Financing | Financed through Soarion Finance |
Why the homeowner replaced a working 1997 R-22 Carrier system
The system was the original 4-ton Carrier from 1997 and was still working. It was 28 years old (1997 to 2025). At the July 21, 2025 survey the tech noted "STILL WORKING" and "some hot spots." The homeowner later wrote that her AC "was still working, I just replaced it because it wasn't efficient." The outdoor unit also used R-22, which is no longer produced.
The R-22 phaseout did not require her to replace it. The EPA says production and import of R-22 (HCFC-22) ended January 1, 2020, but "you may continue to use HCFC-22 in your existing system for as long as necessary" (EPA fact sheet on the R-22 phaseout). The decision here was about efficiency and comfort, not a legal requirement.
When replacing a working AC makes sense, and when it doesn't
- It can make sense when the system is old and low-efficiency (this one was from 1997, with a 12.0 SEER matched-coil rating), has comfort problems such as hot spots, uses R-22 so future repairs are harder to source, and a rebate offsets part of the cost.
- It may not when the system is newer, already reasonably efficient, keeps the home comfortable, and has a modest repair history. A working R-22 system can legally keep running.
- Check first: a load calculation for sizing, the condition of the ductwork, the rated efficiency of the new match on an AHRI certificate, and available utility rebates.
What was installed and how it was sized
| Part | Old | New |
|---|---|---|
| Outdoor unit | Carrier 38BRC048320, 4 tons, R-22, single speed, 1997 | Carrier Infinity 26VNA148W003, 4 tons, variable speed, R-454B, made February 2025 (Carrier 26VNA1 product data) |
| Indoor coil | ADP (Advanced Distributor Products) CEH4821D75 coil, used on the R-22 system | Carrier CVAMA4921XMAEAAA cased coil, TXV |
| Furnace | Carrier gas furnace (model not recorded) | Carrier Infinity 80 58TN0B090C21--20, 80% AFUE, two-stage, variable-speed blower (Carrier 58TN0B furnace product data) |
| Thermostat | Honeywell Home | Carrier Infinity System Control SYSTXCCITC01-C (Carrier Infinity System Control page) |
Building load vs. equipment capacity. The heat load calculation (Energy Design Systems) puts the home's cooling load at 43,726 BTU/h: 40,568 BTU/h sensible and 3,158 BTU/h latent. That is the building load. At the report's 0.9 sensible heat ratio, the required equipment capacity is 45,075 BTU/h, or 3.76 tons. The heating load is 28,143 BTU/h. Inputs: 2,107 sq ft, 101°F summer and 45°F winter outdoor design, 72°F indoor, 15% duct loss and gain. Glass is the largest cooling load at 18,072 BTU/h (41.3%), and east-facing glass is the largest glass area at 153 sq ft (west 107, north 21, south 21). The report's glass exposure chart shows the hourly glass load above average in mid to late afternoon, and its contractor alert notes that some areas may become uncomfortable then.
Size chosen. Carrier's 26VNA1 product data lists this variable-speed model in 2, 3, 4 and 5 ton sizes (Carrier). At 3.76 tons required at the 0.9 sensible heat ratio, 4 tons was chosen; a 3-ton unit would be undersized. The AHRI-rated 45,000 BTU/h of the installed match is effectively matched to the 45,075 BTU/h required at 0.9 SHR (75 BTU/h under). The variable-speed compressor modulates down to 25% of capacity, so it runs at lower capacity on milder days. The system stayed at the same 4-ton size and the existing ductwork was kept.
| Airflow figure | Value | Source |
|---|---|---|
| Required cooling airflow | 1,503 CFM | Heat load report |
| Minimum ductwork design target | 1,600 CFM (4 tons) | Handwritten survey checklist |
| Existing supply / return duct capacity | About 2,315 CFM supply / 2,080 CFM return | Handwritten survey checklist: calculated from the survey duct takeoff (round duct counts by size), not measured |
| Return air grilles | 20x25, 12x12 and 12x12, totaling 788 sq in, against the checklist minimum of 576 sq in for 4 tons | Handwritten survey checklist |
| Airflow verification test, install day | 1,400 CFM at 0.51 in. w.c. static | Carrier Infinity airflow verification test on the thermostat |
Airflow and static pressure
Based on the heat load the home was calling for 1,503 CFM.
For a 4-ton installation, Atlas AC Repair used a minimum ductwork design target of 1,600 CFM.
Based on the visible ductwork the supply was oversized at 2,315 CFM. The concern this created was there potentially not going to be enough static pressure for an Infinity system. In our experience, this often leads to blower motor failure. We have been called out to several Infinity systems installed by other companies where the blower motor kept failing about every two years. Once we corrected the static pressure, the blower motor failures stopped.
The customer did not want to replace any of the ductwork. The work around was our install team took manual dampers with them. Manual dampers install on the supply plenum, and the flex duct attaches to it. This allows us to control air flow per each duct coming off the plenum. We can slowly tighten down the manual dampers till we get the static pressure to manufacturer spec.
After the Carrier Infinity was installed, during the commissioning process the install team found the static pressure was reading 0.51 in. w.c. at 1,400 CFM air flow test. According to Carrier technical support and Carrier's training for our install team, the recommended operating range for an Infinity system during this airflow test is 0.3 to 0.8 in. w.c. Since we were operating within factory spec no manual dampers were installed.
How the install went
- July 21, 2025. Site survey of the attic system, ducts, electrical and outdoor unit. Quote sent the same day.
- July 24, 2025. One-day install, 7:33 AM to 3:23 PM. Line set acid-flushed and kept, new filter drier, drain flushed and tested with 3 gallons, P-trap installed.
- July 30, 2025. All four components registered with Carrier.
- August 7, 2025. CPS Energy rebate application submitted.
Results
Install-day verification
| Reading (install day) | Value | Source |
|---|---|---|
| Nitrogen pressure test | About 400 psi; photo shows 412 psig holding at about 20 minutes | Condenser install form; pressure test photo |
| Evacuation | Vacuum held 30 minutes; 327 microns | Install form; micron gauge photo |
| Superheat / subcooling (R-454B) | 12.4°F / 10.0°F | Digital gauge photo |
| Airflow and static pressure | 1,400 CFM at 0.51 in. w.c. | Infinity airflow verification test |
| Temperature split | 75°F return, 55°F supply, 20°F split | Furnace install form |
Estimated annual cooling savings
Modeled, not measured from utility bills. kWh = tons × 12,000 × 2,209 cooling hours ÷ (SEER2 × 1,000), using Texas TRM zone 3 cooling hours for Bexar County (Texas Technical Reference Manual, Vol. 2, Table 29). The baseline is Carrier's matched-coil rating for the old 38BRC, 12.0 SEER (Carrier 38BRC product data); the actual rating with the ADP coil isn't known. It is converted at 0.95 (RESNET SEER2 conversion) to 11.40 SEER2 = 9,301 kWh a year. New: 19 SEER2 (AHRI 215698378 via Carrier ratings lookup) = 5,581 kWh. Estimated savings: about 3,720 kWh, or $484 a year at CPS Energy's 13.0¢ average (CPS Energy fuel and rate data). No utility bills are on file, so actual savings are not recorded.
Cost, rebate and financing
| Line | Amount |
|---|---|
| 4-ton Carrier Infinity 19 SEER2 variable-speed AC and gas furnace system, installed (equipment, coil, Infinity control, line set flush and filter drier) | $15,292.55 |
| Low-voltage wiring replacement (on the original estimate at $425; removed, see Low-voltage wiring below) | $0.00 |
| Add-ons (UV light, air purifier, media filter, surge protector, dehumidifier, extended labor warranty: offered, not bought) | $0.00 |
| Sales tax | $0.00 |
| Total | $15,292.55 |
| CPS Energy rebate (bill credit) | -$900.00 |
| Net cost after rebate | $14,392.55 |
A $900 CPS Energy rebate was applied for on August 7, 2025, and the homeowner received it as a credit on their electric bill about a month later.
See the CPS Energy HVAC rebate program for current rebate rules. The job was financed through Soarion Finance. See Atlas HVAC financing.
Low-voltage wiring
During the site survey, a short section of low-voltage wiring near the outdoor unit was found in poor condition. Because the new Carrier Infinity system relies on communication between its components, the estimate included $425 to replace that wiring.
During installation, the crew found enough extra cable to remove the deteriorated section and reconnect the remaining wiring without adding a splice. The technicians checked both communication wires for continuity, and both passed. Atlas retained the existing cable and removed the $425 replacement charge from the final bill.
Warranty and follow-up visits
- July 30, 2025. Carrier registration: 10-year parts on the outdoor unit, coil, furnace and control (to July 24, 2035); furnace heat exchanger to July 24, 2065. Atlas 2-year labor warranty.
- August 20, 2025. No power to the thermostat after a storm. The system only needed a reset. No charge.
- September 16, 2025. System shut off on a clogged condensate drain code. The drain line and pan were cleared at no charge. The tech also redirected more airflow to the upstairs bedroom that was running warm, which fixed the problem. We followed up with the customer one week after the airflow adjustment, and the customer reported that it fixed the problem.
What the homeowner said
"All I can say is WOW!!! My entire experience with Atlas has been Awesome! My installer Israel was top notch. Very professional and knowledgeable. I'm so glad I went with Atlas. They are honest and will save you money!"
Marion, Summerfield, San Antonio, TX 78231 · 5-star Google review, July 24, 2025. Quoted word for word.
What this project shows
- A working system was replaced by choice, for efficiency and comfort, not because of a failure or the R-22 phaseout.
- The same 4-ton size and the existing ductwork were kept.
- The upstairs bedroom issue was addressed with an airflow adjustment on a follow-up visit.
- The energy savings are modeled from rated values, not measured.
- This is one home's result, not a sizing rule for every home. Sizing should come from a load calculation for your house.
- Startup static pressure was 0.51 in. w.c. at the 1,400 CFM airflow test, within the 0.3 to 0.8 in. w.c. range Carrier technical support gives for this test, so the manual dampers brought for the oversized ducts were not installed.
Common questions
Should I replace an AC that still works?
It depends on the system. In this job the AC still worked, but it was 28 years old (1997 to 2025), used R-22, carried Carrier's 12.0 SEER matched-coil rating (its actual rating with the ADP coil isn't known), and the survey noted some hot spots. The homeowner replaced it for efficiency. The job cost $15,292.55, or $14,392.55 after a $900 CPS Energy rebate, and the modeled cooling savings are about 3,720 kWh ($484) a year. The R-22 phaseout alone did not require replacement.
How much did this 4-ton Carrier Infinity replacement cost?
$15,292.55 installed, with no add-ons and no sales tax charged, or $14,392.55 after the $900 CPS Energy rebate. That covered the outdoor unit, gas furnace, coil, Infinity control and line set flush. It was financed through Soarion Finance.
How long did the install take?
One day. The crew started at 7:33 AM and finished at 3:23 PM on July 24, 2025.
Was the system upsized?
No. The old and new systems are both 4 tons. The heat load calculation shows 3.76 tons of required cooling capacity at a 0.9 sensible heat ratio (43,726 BTU/h load), so 4 tons was chosen; 3 tons would be undersized.
Can I use a different thermostat with this Carrier Infinity system?
Not for full operation. Carrier says the Infinity System Control is required for the variable-speed outdoor unit, so this job used the SYSTXCCITC01-C.
Was more work needed for the upstairs bedroom?
Yes, one adjustment. In September 2025 the homeowner reported an upstairs bedroom that was running warm. On the September 16, 2025 visit the tech cleared the condensate drain and redirected more airflow to that bedroom, which fixed the problem. No temperature measurements after the fix were recorded. We followed up with the customer one week after the airflow adjustment, and the customer reported that it fixed the problem.
Were the existing oversized ducts a problem?
They could have been. The survey duct takeoff showed about 2,315 CFM of supply capacity against a 1,600 CFM target, which risked low static pressure. The crew brought manual dampers, but startup static measured 0.51 in. w.c. at the 1,400 CFM airflow test, within the 0.3 to 0.8 in. w.c. range Carrier technical support gives for this test, so no dampers were installed.
Proof and sources
- AHRI Directory (search certificate 215698378) and the Carrier AHRI ratings lookup: 19 SEER2, 11 EER2, 45,000 BTU/h for this match
- TDLR license search (look up TACLB00153401E)
- CPS Energy HVAC rebate program
- Carrier spec sheets: 26VNA1 air conditioner product data, 58TN0B furnace product data, CVAMA coil spec sheet
- Texas Technical Reference Manual 13.0, Vol. 2 (cooling hours used in the savings estimate)
- EPA: Residential air conditioning and the phaseout of HCFC-22
Related links
- AC replacement in San Antonio
- Carrier Infinity cost with installation
- 4-ton HVAC unit cost
- HVAC financing
- Carrier President's Award (Atlas is a Carrier dealer; this job is Carrier equipment)
Questions about your own system? Contact Atlas AC Repair.
