Installed June 3, 2026 · The Woodlands, Texas
The homeowner's story. The homeowner had a Carrier 3.5-ton gas system from 2012 serving the 1,807 sq ft downstairs zone of a two-system home. He wanted better energy efficiency and humidity control, and that is why he was looking for a variable speed Carrier Infinity. He wanted a larger system than his old 3.5-ton and did not want to risk the old system's problem happening again. The survey notes record that he was looking for variable speed and asked about a possible dual fuel option, that the home has a fresh air intake, and that he reported dust in the ducts. The downstairs load came to about 3 tons, so our proposals recommended a 3-ton Carrier Infinity, but he preferred the 4-ton. He chose a 4-ton Carrier Infinity gas system with an LED REME HALO air purifier, and we installed it in one day.
Short answer. Atlas replaced a 2012 Carrier 3.5-ton system with a 4-ton Carrier Infinity variable speed gas system in The Woodlands, Texas, for $14,198.21 installed, and on a follow-up call the homeowner said it now keeps up. He chose the 4-ton over our 3-ton recommendation because his old system never kept up. Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, so it can run well below full output.
Key facts
In plain words. The homeowner wanted better energy efficiency and humidity control, so a Carrier 3.5-ton system made in 2012 was replaced with a 4-ton Carrier Infinity variable speed gas system that he chose over the 3-ton we recommended. The table gives the numbers that matter: the downstairs heat load, the equipment, the duct change, the AHRI rating and the $14,198.21 installed price for a one-day install that needed no permit because the home is outside city limits. About one month after the June 3, 2026 install, the homeowner reported on a follow-up call that the system now keeps up.
| Item | Details |
|---|---|
| Location | The Woodlands, Texas |
| Home | Two cooling and heating systems. This job replaced the system that serves the 1,807 sq ft downstairs zone, with 9 ft ceilings and the furnace and coil horizontal in the attic |
| What the homeowner wanted | Better energy efficiency and humidity control, which is why he was looking for a variable speed Carrier Infinity. He wanted a larger system than his old 3.5-ton and did not want to risk the old system's problem happening again. The survey notes record that he was looking for variable speed, that the home has a fresh air intake and that he reported dust in the ducts |
| Old system | Carrier CA16NA042 3.5-ton air conditioner (R-410A, made November 2012), CNPHP4321ALA coil (June 2012) and 58PHA090-16 gas furnace (July 2012, 88,000 BTU/h input, 80% AFUE, single-stage). About 14 years old |
| Heat load result | Downstairs zone, 1,807 sq ft (the certified heat load calculation results): cooling 33,483 BTU/h (27,838 sensible, 5,645 latent, calculated SHR 0.83). Sized at a 0.75 SHR to account for the home's moisture load, including the fresh-air intake: 37,117 BTU/h, 3.09 tons, 1,237 CFM. Heating 19,973 BTU/h, 259 CFM |
| Sizing | The downstairs load came to about 3 tons, which is why Atlas's proposals recommended a 3-ton Carrier Infinity. The homeowner wanted more capacity than his old 3.5-ton system had, so the 4-ton was the homeowner's choice. The 4-ton system is larger than Atlas's load-based recommendation, but its variable-speed compressor can reduce capacity substantially during lower-load conditions. Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, so it can run well below its full output when the load is lower than the 33,483 BTU/h peak. That made the homeowner's preferred 4-ton option more workable than a 4-ton single-stage system would have been. A 4-ton single-stage system would have been oversized for this load and Atlas would not have installed it |
| New system | Carrier Infinity 4-ton variable speed air conditioner (26VNA148W003, R-454B), CVAMA4921XMA cased coil, two-stage 58TN0B090C17--16 gas furnace, SYSTXCCITC01-C Infinity System Control and an RGF LED REME HALO air purifier |
| Ductwork | Two supply runs upsized from 8 inch to 9 inch because the two-stage furnace delivers 965 CFM on first stage and 1,455 CFM on second stage, so the supply ducts needed to carry 1,455 CFM. Supply chart total 1,325 CFM before, 1,455 CFM after. Return total 1,780 CFM from the survey checklist, which also covers 1,455 CFM |
| Airflow in Comfort mode | The system is set to Comfort mode, and in cooling it ramps as high as 1,400 CFM. Chart supply capacity is 1,455 CFM and the checklist return total is 1,780 CFM |
| Static pressure | 0.61 in. W.C. total external static pressure, within the 0.3 to 0.8 in. W.C. range Carrier technical support and training recommends for the Infinity airflow test |
| AHRI rating | AHRI 215698368: 26VNA148W*030* + CVAMA4921XMA*+UI + 58TN*B090C17**16, 45,000 BTU/h, 19 SEER2, 10.5 EER2 (Carrier AHRI ratings tool) |
| Permit | Not required (outside city limits; no city or county HVAC permit applied) |
| Installed price | $14,198.21, financed through Wells Fargo, after a $1,700 Carrier Cool Cash instant discount and a $762.30 fee discount. See the Cost section. |
| Install time | One day, June 3, 2026. Installed by Fredi (lead) and Pablo |
| Result | About one month after the June 3, 2026 install, Atlas made a follow-up call to verify everything was working correctly. The homeowner said the system now keeps up and he is happy with the humidity level. Both are what the homeowner reported on that call. This case study has no measurement of how the house cools and no humidity measurement |
The old system: a 2012 Carrier 3.5-ton gas system
In plain words. The system being replaced was a Carrier 3.5-ton air conditioner with a coil and 80% gas furnace, all made in 2012, so about 14 years old. The data tags give the models and dates. The survey notes also record a fresh air intake and a homeowner report of dust in the ducts. The result of the replacement is a new matched variable speed system.
Brian surveyed the home on May 27, 2026. What the survey and the data tags showed:
- Carrier CA16NA042 air conditioner. A 3.5-ton, R-410A unit made November 2012. Carrier's product data lists this match at 41,000 BTU/h, 13.2 EER and 16.0 SEER (CA16NA product data, AHRI 4584811).
- Carrier CNPHP4321ALA coil. R-410A, made June 2012.
- Carrier 58PHA090-16 furnace. 88,000 BTU/h input, single-stage, 80.0% AFUE per Carrier's product data (58PHA product data), made July 2012.
- Ductwork. The supply plenum had seven flex takeoffs: five 8 inch, one 9 inch and one 10 inch. The survey checklist recorded a return airflow of 1,780 CFM.
- A large glass load. Glass is 46.5% of the cooling load in the certified heat load calculation results for the downstairs zone, with 131 sq ft facing east and 92 sq ft facing west.
- Fresh air intake. The survey notes record that the home has a fresh air intake.
- Dust. The survey notes record that the homeowner reported dust in the ducts.
What the homeowner wanted, and the result
In plain words. The homeowner wanted better energy efficiency and humidity control, which is why he was looking for a variable speed Carrier Infinity. He wanted more capacity than his old 3.5-ton system had and did not want to risk a repeat, so he insisted on a larger unit. The survey notes record that he was looking for variable speed, asked about a possible dual fuel option and reported dust in the ducts. We installed a 4-ton variable speed Carrier Infinity gas system and an LED REME HALO air purifier, and the homeowner's review is a 5-star one. About one month after the June 3, 2026 install, Atlas made a follow-up call to verify everything was working correctly, and the homeowner said the system now keeps up and he is happy with the humidity level. The table shows each request, what we did and the result.
| What the homeowner said | What we did | Result |
|---|---|---|
| He wanted more capacity than his old 3.5-ton system had, and he did not want to risk a repeat of its problem | Our proposals recommended a 3-ton Carrier Infinity because the downstairs load came to about 3 tons. We installed the 4-ton Carrier Infinity gas system he chose | Installed as he chose. On the follow-up call about one month after the June 3, 2026 install, the homeowner reported that the system now keeps up. This case study has no measurement of how the house cools. |
| Better energy efficiency | Installed a Carrier Infinity system rated 19 SEER2 (AHRI 215698368) | Our estimate, not a measurement, is in the energy savings section. The furnaces are both 80% AFUE. |
| Better humidity control | Installed a variable speed Carrier Infinity system. Carrier lists the 58TN0B furnace as part of its IdealHumidity system | On the follow-up call about one month after the June 3, 2026 install, the homeowner reported that he is happy with the humidity level. This case study has no humidity measurement for the home. |
| Looking for a variable speed system (survey notes) | Installed a variable speed Carrier Infinity 26VNA148W003 air conditioner, a two-stage variable speed 58TN0B furnace and an Infinity System Control | Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM. |
| Asked about a possible dual fuel option (survey notes) | Wrote estimate options that included a 3-ton Carrier Infinity dual fuel system. The homeowner approved the all gas Carrier Infinity option | The installed system is an air conditioner with a gas furnace. |
| Reported dust in the ducts (survey notes) | Added an RGF LED REME HALO air purifier at the furnace and coil | Recorded here as what was installed. We have no measurement of dust. |
| A professional install | One day install by Fredi and Pablo | The review: "The Atlas Team led by Fredi was outstanding and took great care in the professional installation of our HVAC system." |
The heat load and the system size
In plain words. The certified heat load calculation results are for the 1,807 sq ft downstairs zone that this system serves. Cooling is 33,483 BTU/h: 27,838 BTU/h to lower the temperature (sensible) and 5,645 BTU/h to remove moisture (latent). Heating is 19,973 BTU/h. The sensible heat ratio, or SHR, is the share of a system's cooling that goes to lowering the temperature instead of removing moisture. For this project, the certified heat load calculation used a 0.75 SHR to account for the home's moisture load, including the fresh-air intake. That gives 37,117 BTU/h, or 3.09 tons, with 1,237 CFM of airflow. The downstairs load came to about 3 tons, which is why our proposals recommended a 3-ton Carrier Infinity. The homeowner wanted more capacity than his old 3.5-ton system had, so the 4-ton was his choice. The 4-ton system is larger than Atlas's load-based recommendation, but its variable-speed compressor can reduce capacity substantially during lower-load conditions. That made the homeowner's preferred 4-ton option more workable than a 4-ton single-stage system would have been. Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, so on most hours it is expected to run well below its full output.
The certified heat load calculation results cover the 1,807 sq ft downstairs zone. The inputs were 2 residents, 9 ft ceilings, R-13 walls, an R-5 floor and an R-29 ceiling, glass at U 0.5 and SHGC 0.85 (131 sq ft east, 92 sq ft west, 19 sq ft north and 19 sq ft south), 101°F outdoor and 72°F indoor summer design, 45°F outdoor and 72°F indoor winter design, a 77°F summer wet bulb, 51 grains of moisture difference, 0.6 air changes per hour of cooling infiltration and 0.8 for heating, and 10% duct gain and loss.
| Cooling load item | BTU/h | Share |
|---|---|---|
| Glass | 15,574 | 46.5% |
| Latent infiltration | 5,245 | 15.7% |
| Sensible infiltration | 4,825 | 14.4% |
| Duct gain | 2,748 | 8.2% |
| Internal | 2,400 | 7.2% |
| Wall | 1,831 | 5.5% |
| Sensible people | 460 | 1.4% |
| Latent people | 400 | 1.2% |
| Total | 33,483 | 27,838 sensible, 5,645 latent |
| Heating load item | BTU/h | Share |
|---|---|---|
| Floor | 6,940 | 34.7% |
| Infiltration | 5,989 | 30% |
| Glass | 3,524 | 17.6% |
| Duct loss | 1,816 | 9.1% |
| Wall | 1,705 | 8.5% |
| Total | 19,973 | 259 CFM required heating airflow |
The calculated sensible heat ratio is 0.83 (27,838 divided by 33,483). The report sizes the equipment at 0.75 SHR, which gives 37,117 BTU/h (27,838 divided by 0.75), or 3.09 tons (37,117 divided by 12,000), with 1,237 CFM of required cooling airflow. The report describes that figure as the total equipment capacity required to have the sensible capacity to cover the sensible cooling load. The report's contractor alert says that if the hourly glass load exceeds the average glass load, especially in mid to late afternoon, areas of the home may become uncomfortable, and suggests a variable comfort system (staged or modulating cooling and heating, and variable airflow) and room or zone temperature controls.
How the size was chosen. The downstairs load, sized at a 0.75 SHR, came to 37,117 BTU/h, or 3.09 tons, which is why our proposals for this home recommended a 3-ton Carrier Infinity, in both a gas and a dual fuel option. The homeowner wanted a 4-ton system because his older 3.5-ton system never kept up and he did not want to risk that happening again, so the 4-ton was the homeowner's choice.
Why we went forward with the 4-ton. Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, and the cooling airflow settings in that table run from 400 CFM up to 1,400 CFM. The variable speed system can therefore run well below its full output to match lower loads, so on most hours it is expected to run below the downstairs peak cooling load of 33,483 BTU/h. In Comfort mode its cooling airflow ramps up as high as 1,400 CFM. So in cooling the system can run at lower output to match the downstairs load (33,483 BTU/h and 1,237 CFM). Per Carrier's 58TN0B product data, the matchup of the 26VNA148W003 with the CVAMA4921XMA coil and the 58TN0B090C17 furnace can operate down to 965 CFM of heating airflow, and the two-stage furnace has a low heat stage for the 19,973 BTU/h load. The 4-ton system is larger than Atlas's load-based recommendation, but its variable-speed compressor can reduce capacity substantially during lower-load conditions. That made the homeowner's preferred 4-ton option more workable than a 4-ton single-stage system would have been. If the homeowner had wanted a 4-ton single-stage system, it would have been truly oversized for this load and Atlas would not have installed it. The variable speed Infinity's ability to run well below its full output is what made the 4-ton acceptable.
The equipment. The old air conditioner was a 3.5-ton, and the new Carrier Infinity 26VNA148W003 is a 4-ton. Carrier rates the match at 45,000 BTU/h in AHRI 215698368 (old match, AHRI 4584811: 41,000 BTU/h). Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, so on milder days it can run well below full output.
Ductwork: two supply runs upsized
In plain words. The system is set to Comfort mode, and the two-stage furnace delivers 965 CFM on first stage and 1,455 CFM on second stage, so the supply ductwork needed to be modified to carry 1,455 CFM. Two of the seven supply runs were upsized from 8 inch to 9 inch. Using the NCI field duct sizing chart, that raises the supply capacity from 1,325 CFM to 1,455 CFM, matching the second stage heating airflow. The survey checklist recorded a return total of 1,780 CFM, which also covers 1,455 CFM. These are chart and checklist values, not measured airflow. No other duct changes were made.
Each duct's airflow is the design airflow for its round size from the NCI field duct sizing chart (flexible duct): 8 inch 160 CFM, 9 inch 225 and 10 inch 300. These are chart values, not measured airflow. The invoice bills the change as a duct run upsize, two runs at $572 each.
| Supply run size | Chart CFM each | Runs before | CFM before | Runs after | CFM after |
|---|---|---|---|---|---|
| 8 inch | 160 | 5 | 800 | 3 | 480 |
| 9 inch | 225 | 1 | 225 | 3 | 675 |
| 10 inch | 300 | 1 | 300 | 1 | 300 |
| Supply total, 7 runs | 1,325 | 1,455 | |||
| Furnace airflow: first stage 965 CFM, second stage 1,455 CFM | Supply chart total after: 1,455 CFM | ||||
| Cooling airflow in Comfort mode: ramps as high as 1,400 CFM | Supply chart total after: 1,455 CFM | ||||
| Return total from the survey checklist | 1,780 CFM | ||||
Comfort mode airflow
In plain words. The system is set to Comfort mode. In cooling it ramps as high as 1,400 CFM, and the supply and return ducts can carry that.
In Comfort mode the cooling airflow ramps as high as 1,400 CFM. With the two upsized runs the supply chart total is 1,455 CFM and the checklist return total is 1,780 CFM, so both are above 1,400 CFM. Before the upsizes the supply chart total was 1,325 CFM, below 1,400 CFM and below the furnace's 1,455 CFM second stage. On heating, the furnace delivers 965 CFM on first stage and 1,455 CFM on second stage, which the 1,455 CFM supply total and the 1,780 CFM return total cover. The duct figures are chart and checklist values, as explained above.
What was installed
In plain words. The old air conditioner, coil and furnace were replaced with a matched Carrier Infinity system: a 4-ton variable speed air conditioner, a cased coil, a two-stage variable speed gas furnace and an Infinity System Control, plus an LED REME HALO air purifier. The furnace is an 80% AFUE model, the same as the old one. The table links every installed model to Carrier or RGF.
| Part | Old | New |
|---|---|---|
| Outdoor unit | Carrier CA16NA042, 3.5 tons, R-410A, made November 2012 | Carrier Infinity 26VNA148W003, 4 tons, variable speed, R-454B (product page, product data) |
| Indoor coil | Carrier CNPHP4321ALA, R-410A, made June 2012 | Carrier CVAMA4921XMA cased coil with TXV, R-454B, made April 2026 (product page, spec sheet) |
| Furnace | Carrier 58PHA090-16, 88,000 BTU/h input, single-stage, 80% AFUE, made July 2012 | Carrier Infinity 80 58TN0B090C17--16, 90,000 BTU/h input, two-stage, variable speed, 80% AFUE (product page, product data) |
| Control | Honeywell touchscreen thermostat | Carrier Infinity System Control SYSTXCCITC01-C (product page, product data) |
| Air treatment | None listed | RGF LED REME HALO air purifier at the furnace and coil |
| Drain pan | Existing pan | New drain pan with condensate safety switches |
| Filter | Not recorded | 4" Honeywell Filter Base with MERV 11 filter, 20x25x4 size, in the filter rack at the new furnace and coil |
| Ductwork | Seven supply runs: five 8 inch, one 9 inch, one 10 inch | Two supply runs upsized from 8 inch to 9 inch |
| Line set | Existing line set acid-flushed and reconnected, with a new filter drier (from the estimate) | |
| Surge protection | Not recorded | Two DITEK surge protectors on the equipment order |
Carrier lists the 26VNA1 as an Infinity variable speed air conditioner with sound as low as 55 dBA in low speed. For the 4-ton size, Carrier rates sound power at 64 dBA at minimum cooling speed and 72 dBA at full speed (26VNA1 product data). Carrier requires the Infinity System Control with Greenspeed Intelligence for the variable speed drive, and lists the 58TN0B as a two-stage, 80% AFUE, variable speed furnace that is part of its IdealHumidity system (58TN0B product data). The coil ships with a refrigerant leak dissipation system (CVAMA spec sheet). The LED REME HALO is RGF's HALO LED whole-home in-duct air purifier. It uses mercury-free LED UV-C light and a washable catalyst, and it turns on and off with the blower instead of running all the time. The matched system is listed in the AHRI Certification Directory under AHRI 215698368 (26VNA148W*030* + CVAMA4921XMA*+UI + 58TN*B090C17**16, 45,000 BTU/h, 19 SEER2, 10.5 EER2).
How the install went
In plain words. The old system came out and the new one went in over one day, June 3, 2026. Fredi led the crew with Pablo. The refrigerant lines were pressure tested with nitrogen and evacuated before startup, and the job notes record the system cooling and heating properly at the end of the day.
Brian did the site survey on May 27, 2026. Fredi led the install with Pablo, and the job notes record the crew on site from about 9 AM to 3:40 PM on June 3, 2026. Fredi and Pablo are Carrier Infinity trained to install Infinity systems. A permit was not required for this job. The home is outside city limits in The Woodlands, so no city or county HVAC permit applied. Atlas pulls a permit on every changeout that needs one. Atlas AC Repair, a Carrier Factory Authorized Dealer, operates under Texas ACR license TACLB00153401E, held by Timothy Carpenter, who is NATE-certified and oversaw the install.
Line set, evacuation and commissioning
In plain words. The existing line set was acid-flushed and reused, with a new filter drier. The new lines were pressure tested with nitrogen and evacuated before startup. The table lists what the photos recorded. The outcome is a system started on the existing flushed lines.
| Item | Recorded | Source |
|---|---|---|
| Line set | Existing line set acid-flushed and reconnected, new filter drier | Estimate scope and install photos |
| Nitrogen pressure test | About 252 psig on the digital manifold, shown as an N2 test (test pressure, not a running pressure) | Gauge photo |
| Evacuation | 378 microns, with the gauge's rate display at 0 per minute | Micron gauge photo |
| Control equipment summary | Infinity System Control equipment summary lists furnace 58TN0B090C171116 (two-stage gas heat), variable capacity AC 48KBTU/H 26VNA148W00300, evaporator CVAM*4921, a refrigerant dissipation board and UV lights | Control screen photo |
| Total external static pressure | 0.61 in. W.C., within the 0.3 to 0.8 in. W.C. range Carrier technical support and training recommends for the Infinity airflow test | Atlas field reading |
| Duct surface temperatures | 55.2°F on a supply duct and 75.2°F on a return duct, from an infrared thermometer on the outside of the foil flex. These are surface readings, not air temperatures | Install photos |
Total external static pressure, in inches of water column (in. W.C.), shows how hard the blower has to push air through the ducts, filter and grilles. The recommended range of 0.3 to 0.8 in. W.C. for the Infinity airflow test is from Carrier technical support and training. The 0.61 in. W.C. reading is inside it. We do not have a reading from before the duct changes, so we cannot say how much the upsized runs changed it.
Cost
In plain words. The final installed price was $14,198.21. It starts with the $15,516.51 system price, takes off the $1,700 Carrier Cool Cash instant discount, adds $1,144 for two duct run upsizes and an $877 LED REME HALO that an $877 Easy Estimate discount offset, and ends with a $762.30 Wells Fargo fee discount. The job was financed through Wells Fargo. The table shows every line item.
| Line item | Amount |
|---|---|
| 4-ton Carrier Infinity gas system (variable speed air conditioner, coil, two-stage furnace and Infinity System Control) | $15,516.51 |
| Carrier Cool Cash instant discount | -$1,700.00 |
| Duct run upsize, 2 runs (2 at $572.00) | $1,144.00 |
| LED REME HALO | $877.00 |
| Easy Estimate discount | -$877.00 |
| Subtotal | $14,960.51 |
| Wells Fargo fee discount | -$762.30 |
| Installed price | $14,198.21 |
For typical ranges, see our Carrier Infinity cost guide and HVAC replacement cost guide. Learn about our HVAC financing options.
Energy savings estimate
In plain words. This is an estimate, not a measurement. The old air conditioner is published at 16.0 SEER, which is about 15.2 SEER2, and the new system is rated 19 SEER2. On the standard Texas method that works out to about 523 kWh a year less cooling energy at the actual sizes (3.5 tons old, 4 tons new), or about 1,395 kWh a year less if both were the same size. The furnaces are both 80% AFUE, so no gas savings are claimed.
Old rating. Carrier's CA16NA product data lists the old match (CA16NA042 + CNPH*4321A + 58PH*090-16, AHRI 4584811) at 41,000 BTU/h, 13.2 EER and 16.0 SEER (CA16NA-04PD). This comes from published product data, not a test of this unit. At RESNET's 0.95 conversion factor for ducted split systems (RESNET Addendum 71i), 16.0 SEER is 15.2 SEER2.
New rating. AHRI 215698368 lists 19 SEER2 and 10.5 EER2 (Carrier AHRI ratings tool).
The math. kWh = tons × 12,000 × cooling hours ÷ (SEER2 × 1,000). Cooling hours are 2,209 full-load hours, the Texas Technical Reference Manual 13.0 value for climate zone 3, Houston (Vol. 2, Table 29). The method scales energy with tons, so the half-ton larger system is counted as using more energy. The table shows both views.
| Comparison | Old kWh per year | New kWh per year | Estimated savings |
|---|---|---|---|
| Actual sizes (old 3.5 tons, new 4 tons) | 6,104 | 5,581 | 523 kWh |
| Efficiency only (both at 4 tons) | 6,976 | 5,581 | 1,395 kWh |
Old at 3.5 tons: 3.5 × 12,000 × 2,209 ÷ (15.2 × 1,000) = 6,104 kWh. Old at 4 tons: 4 × 12,000 × 2,209 ÷ (15.2 × 1,000) = 6,976 kWh. New at 4 tons: 4 × 12,000 × 2,209 ÷ (19 × 1,000) = 5,581 kWh. Actual use depends on weather, thermostat settings and the home, and the old unit has aged since it was rated. No dollar figure is shown because homes in this area choose their own electric provider. To estimate dollars, multiply the kWh by the rate on your electric bill.
Heating. The old 58PHA090-16 furnace is rated 80.0% AFUE (58PHA product data) and the new Infinity 80 is also 80% AFUE (58TN0B product data), so no gas savings are claimed. The changes are two-stage heat and a variable speed blower.
Warranty
In plain words. Atlas registered the new Carrier equipment with Carrier on June 5, 2026. The registration lists enhanced parts coverage through June 3, 2036 on the air conditioner, coil and furnace, and heat exchanger coverage on the furnace through June 3, 2066. Atlas adds a 2-year labor warranty, and the LED REME HALO has its own RGF warranty.
The Carrier registration of June 5, 2026 covers the 26VNA148W003 air conditioner, the CVAMA4921XMA coil and the 58TN0B090C17--16 furnace, each with enhanced parts warranty through June 3, 2036, and the furnace heat exchangers through June 3, 2066. The estimate lists a 2-year Atlas warranty on labor, with optional 5 and 10-year labor warranties at additional cost. The LED REME HALO was registered with RGF on a warranty certificate showing install on June 3, 2026 and coverage through June 2, 2031.
Service since the install
In plain words. There were two calls since the June 3, 2026 install, and both came after a power outage. When power was restored, the Infinity control displayed an error code, and Atlas resolved it from the office both times, with no site visit.
- June 9, 2026. After a power outage, the Infinity control displayed an error code when power was restored. The homeowner called Atlas, and we resolved it from the office with no site visit.
- October 2026. After a power outage, the Infinity control displayed an error code, fault code 179, when power was restored. The homeowner called Atlas, and we resolved it from the office with no site visit.
What the homeowner said
In plain words. The homeowner wrote a 5-star Google review on the day of the install, praising the crew led by Fredi and the professional installation. The full review is below, word for word.
"The Atlas Team led by Fredi was outstanding and took great care in the professional installation of our HVAC system. Highly recommend Atlas Air."
Joe, The Woodlands, Texas · 5-star Google review, June 3, 2026. Quoted word for word.
Related pages
- 4-ton HVAC unit cost guide
- 4-ton AC unit price guide from a real AC company
- AC installation in the Houston area
- Summerfield Carrier Infinity 4-ton gas system replacement case study
- How we sized AC for a 2,000 sq ft house (Fredericksburg case study)
- League City Carrier Infinity 5-ton zoned system replacement case study
- Ductwork replacement cost guide
- All Atlas AC Repair case studies
Common questions
What did Atlas install in this home in The Woodlands, Texas?
A 4-ton Carrier Infinity gas system: a variable speed 26VNA148W003 air conditioner (R-454B), a CVAMA4921XMA cased coil, a two-stage 58TN0B090C17--16 gas furnace and an Infinity System Control, plus an LED REME HALO air purifier, a 4-inch Honeywell Filter Base with MERV 11 filter and two supply duct runs upsized from 8 inch to 9 inch. It replaced a Carrier 3.5-ton air conditioner, coil and 80% gas furnace made in 2012. The installed price was $14,198.21 and the job took one day, June 3, 2026.
Why did the homeowner choose a 4-ton system when Atlas recommended a 3-ton?
The homeowner chose the 4-ton system because his older 3.5-ton system never kept up and he did not want to risk that happening again, even though Atlas's proposals recommended a 3-ton Carrier Infinity. The certified heat load calculation results put the 1,807 sq ft downstairs zone that this system serves at a peak cooling load of 33,483 BTU/h (2.79 tons). Sized at a 0.75 sensible heat ratio, the calculation gives 37,117 BTU/h, or 3.09 tons, with 1,237 CFM of airflow. The sized load came to about 3 tons, which is why Atlas's proposals recommended a 3-ton Carrier Infinity. The 4-ton system is larger than Atlas's load-based recommendation, but its variable-speed compressor can reduce capacity substantially during lower-load conditions. That made the homeowner's preferred 4-ton option more workable than a 4-ton single-stage system would have been. Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, so it can run well below its full output to match lower loads, and on most hours it is expected to run below the 33,483 BTU/h peak load. In cooling it can run at lower output to match the downstairs load (33,483 BTU/h and 1,237 CFM). Per Carrier's product data, this matchup (the CVAMA4921XMA coil and the 58TN0B090C17 furnace) can operate down to 965 CFM of heating airflow, and the two-stage furnace has a low heat stage for the 19,973 BTU/h heating load. If the homeowner had wanted a 4-ton single-stage system, it would have been truly oversized for this load and Atlas would not have installed it. The variable speed Infinity's ability to run well below its full output is what made the 4-ton acceptable.
Did the new system keep up?
Yes, according to the homeowner. About one month after the June 3, 2026 install, Atlas made a follow-up call to verify everything was working correctly, and the homeowner said the system now keeps up and he is happy with the humidity level. He wanted a larger system than his old 3.5-ton, which is why he chose a 4-ton system. This is what the homeowner reported on that call. We have no measurement of how the house cools or of the humidity level.
What size AC does an 1,800 sq ft downstairs zone need?
About 3 tons for this 1,807 sq ft downstairs zone, but it depends on the house. The certified heat load calculation results put this zone, with 9 ft ceilings, at 33,483 BTU/h of cooling (27,838 sensible and 5,645 latent) and 19,973 BTU/h of heating. For this project, the certified heat load calculation used a 0.75 SHR to account for the home's moisture load, including the fresh-air intake. At that ratio, the total is 37,117 BTU/h, or 3.09 tons, and 1,237 CFM. Glass was the largest cooling item at 46.5%. These numbers depend on the glass, shade, insulation and air leakage, so they are not a rule for another home.
Does window glass affect the cooling load?
Yes. The downstairs zone has 131 sq ft of east facing glass, 92 sq ft of west facing glass and 19 sq ft each on the north and south sides. In the certified heat load calculation results glass is 15,574 BTU/h, 46.5% of the cooling load, the largest single item. The report's contractor alert says areas of a home may become uncomfortable when the hourly glass load exceeds the average, and suggests a variable comfort system and room or zone temperature controls.
What changed in the ductwork?
Two of the five 8 inch supply runs (the home has seven supply runs in all) were upsized to 9 inch so the supply ductwork could carry 1,455 CFM. The two-stage furnace delivers 965 CFM on first stage and 1,455 CFM on second stage. Using the NCI field duct sizing chart for flexible duct, that raised the supply capacity from 1,325 CFM to 1,455 CFM, matching the second stage heating airflow. The survey checklist records a return total of 1,780 CFM, which also covers 1,455 CFM. In Comfort mode the cooling airflow ramps as high as 1,400 CFM, which the 1,455 CFM supply and 1,780 CFM return also cover. These are chart and checklist values, not measured airflow. No other duct changes were made.
What was the static pressure on this system?
Total external static pressure was 0.61 in. W.C. Carrier technical support and training recommends a static pressure range of 0.3 to 0.8 in. W.C. for the Infinity airflow test, and the reading is within that range. We do not have a reading from before the duct changes.
Why Carrier Infinity?
The homeowner wanted better energy efficiency and humidity control, which is why he was looking for a variable speed Carrier Infinity. The survey notes record that he was looking for variable speed, that the home has a fresh air intake and that he reported dust in the ducts. He chose Carrier Infinity. Carrier lists the 26VNA1 as having a variable speed compressor, and the 58TN0B as a two-stage, 80% AFUE, variable speed furnace with an IdealHumidity system. Based on Carrier's Infinity data sheets, the system's minimum cooling airflow is 400 CFM, so the system can run well below its full output to match lower loads.
What is the AHRI rating of the new system?
The new system is rated 45,000 BTU/h, 19 SEER2 and 10.5 EER2. AHRI 215698368 lists the 26VNA148W*030* air conditioner with the CVAMA4921XMA*+UI coil and the 58TN*B090C17**16 furnace at those figures, according to Carrier's AHRI ratings tool. It is still called a 4-ton system because the nominal size is 48,000 BTU/h (4 x 12,000), and the AHRI rating is the tested capacity at standard conditions for this matched condenser, coil and furnace, so it reads lower than the nominal size. The old 3.5-ton match, AHRI 4584811, is listed in Carrier's product data at 41,000 BTU/h, 13.2 EER and 16.0 SEER.
How much energy will the new system save?
Our estimate, not a measurement, is about 523 kWh of cooling energy a year at the actual sizes (old 3.5 tons, new 4 tons), or about 1,395 kWh a year if both were 4 tons. It uses the old unit's published 16.0 SEER (about 15.2 SEER2), the new 19 SEER2 rating and 2,209 full-load cooling hours from the Texas Technical Reference Manual for the Houston climate zone. The furnaces are both 80% AFUE, so no gas savings are claimed.
How much did the replacement cost?
$14,198.21 installed in The Woodlands in June 2026, financed through Wells Fargo, after a $1,700 Carrier Cool Cash instant discount and a $762.30 Wells Fargo fee discount. The line items are $15,516.51 for the system, $1,144 for two duct run upsizes and $877 for an LED REME HALO, which an $877 Easy Estimate discount offset.
Did the job need a permit?
No. A permit was not required for this job. The home is outside city limits in The Woodlands, so no city or county HVAC permit applied. Atlas pulls a permit on every changeout that needs one.
How long did the install take, and who did it?
One day, June 3, 2026. Fredi led the crew with Pablo, and Timothy Carpenter, who is NATE-certified, oversaw the install. Fredi and Pablo are Carrier Infinity trained to install Infinity systems. Brian did the site survey on May 27, 2026.
Has there been any service since the install?
Two calls since the June 3, 2026 install, both after power outages. On June 9, 2026 and again in October 2026, the Infinity control displayed an error code when power was restored, and the homeowner called Atlas. We resolved both from the office, with no site visit. The October call involved fault code 179.
Proof and sources
- NCI field duct sizing chart (flexible duct) for the per-duct airflow values; the certified heat load calculation results for the downstairs zone; site survey (May 27, 2026) checklist and photos; Carrier technical support and training for the Infinity airflow test static pressure range; estimate and invoice; install photos; Carrier registration (June 5, 2026); RGF warranty registration; service call records.
- Carrier product pages and data: 26VNA1 product page and product data; 58TN (Infinity 80) product page and 58TN0B product data; CVAM coil product page and CVAMA spec sheet; SYSTXCCITC01-C and control product data; RGF LED REME HALO.
- RGF product page: HALO LED whole-home in-duct air purifier.
- Carrier Enterprise product pages: 26VNA148W003, CVAMA4921XMA, 58TN0B090C17--16 and SYSTXCCITC01-C.
- AHRI Certification Directory listing AHRI 215698368, with figures read from Carrier's AHRI ratings tool. Old match: Carrier CA16NA product data (CA16NA-04PD, AHRI 4584811) and 58PHA product data (link).
- RESNET Addendum 71i for the SEER2 conversion and Texas Technical Reference Manual 13.0, Vol. 2, Table 29 for the cooling hours.
- TDLR license search for TACLB00153401E, the license Atlas AC Repair operates under.
