McKinney 75070 HVAC Replacement: 3.5-Ton Daikin R-32 Case Study

Project completed October 11, 2026 | McKinney, Texas 75070

On October 11, 2026, Greentech Engineering Heating & Air Conditioning — DFW HVAC replaced a no-cool HVAC system in a two-level McKinney, TX 75070 home with a nominal 3.5-ton Daikin R-32 air conditioner, horizontal evaporator coil and 80% AFUE gas furnace. Before approval, the written proposal identified the equipment, AHRI reference, installation scope and warranty. AHRI reference 214856170 rates the exact combination at 39,000 BTUH, 15.2 SEER2 and 12.0 EER2. This case documents one home and is not a sizing recommendation for other properties.

Project facts

• Location: McKinney, Texas 75070
• Property: Two-level single-family house
• Reported problem: No cooling; the specific failed component was not provided for publication
• Installation completed: October 11, 2026
• System: Nominal 3.5-ton Daikin R-32 straight-cool A/C with horizontal coil and 80% AFUE gas furnace
• Outdoor model: DC4SEA4210AA
• Indoor coil: CHPTA4830C3AA
• Gas furnace: DR80SN0805CXAA
• AHRI reference: 214856170
• Certified performance: 39,000 BTUH, 15.2 SEER2 and 12.0 EER2
• Labor warranty: Complimentary three years/1,095 days, subject to written terms

The no-cooling call and the decision to replace

The homeowner reported that the home was not cooling. Greentech performed a diagnostic visit and prepared a written, itemized proposal for a complete matched-system replacement. The available publication record does not identify the failed component, diagnostic measurements, system age, previous repair history or a documented repair alternative, so this case does not reconstruct those details.

‍

What the transparent estimate documented

Before the homeowner approved the replacement, Greentech’s proposal identified:

• the complete outdoor unit, indoor coil and furnace combination;
• model information and AHRI Certified Reference Number 214856170;
• the certified capacity and efficiency rating;
• removal, refrigerant recovery and disposal work;
• drain, gas, refrigerant-line and equipment-connection work;
• pressure testing, evacuation, startup and operational testing; and
• contractor labor-warranty coverage.

The proposal allowed the homeowner to review the equipment and related work as one defined scope instead of comparing only an online equipment price. Greentech’s estimate format is designed to show the authorized line items and total price before work begins.

For a broader homeowner checklist, see what an HVAC estimate should include.

What the homeowner was deciding

• Problem reported: The home was not cooling.
• What Greentech documented: The proposed equipment combination, model family, AHRI reference, rated performance, installation tasks and warranty.
• Facts confirmed: The old outdoor unit used R-410A; the new matched Daikin system uses an R-32 outdoor unit and compatible indoor coil; installation was completed October 11; the exact AHRI combination is certified at 39,000 BTUH, 15.2 SEER2 and 12.0 EER2.
• Option selected: Complete replacement of the A/C, horizontal coil and gas furnace described in the proposal.
• What remained: The scope indicates that the existing copper refrigerant line set was retained after flushing, preparation and required modification. It does not document a whole-home duct replacement.
• What this case does not prove: The exact failure cause, a documented repair alternative, Manual J sizing, rebate eligibility, permit or inspection results, price superiority, energy savings or measured comfort improvement.

‍

The selected Daikin matched system

The replacement combines three components. The family descriptions below are linked to Daikin’s official product information; the exact project rating comes from the listed AHRI combination.

• Daikin DC4SEA4210AA: a nominal 42,000-BTU/3.5-ton, single-stage R-32 outdoor air conditioner.
• Daikin CHPTA4830C3AA: a horizontal R-32 evaporator coil with a factory-installed TXV. Its cabinet family can serve a range of applications; it is not evidence of a separate 4-ton system.
• Daikin DR80SN0805CXAA: an 80,000-BTU-input, single-stage, 80% AFUE gas furnace with a 9-speed-tap ECM blower.

An ECM blower does not make the outdoor unit variable-capacity. The outdoor air conditioner in this project is single-stage.

Why the AHRI number matters

An AHRI rating applies to a specified combination of outdoor equipment, indoor coil and furnace or blower—not to the condenser by itself. AHRI reference 214856170 rates this listed combination at 39,000 BTUH certified cooling capacity, 15.2 SEER2 and 12.0 EER2.

The outdoor model belongs to the nominal 42,000-BTU/3.5-ton size class. The 39,000-BTUH figure is the certified capacity of the exact matched combination under standardized test conditions. The two figures describe different specifications and are not contradictory.

Before installation, Greentech’s written proposal identified AHRI Certified Reference Number 214856170 for the selected equipment combination. The installation was completed on October 11, 2026. The AHRI certificate copy dated October 14 subsequently verifies that model combination at 39,000 BTUH, 15.2 SEER2 and 12.0 EER2. The later date records when the certificate copy was generated or retrieved; it does not mean the October 14 document selected the equipment before installation.

Homeowners can search certified equipment combinations through the official AHRI Directory of Certified Product Performance. The project certificate remains the controlling source for the exact reference number and ratings reported here.

The full AHRI certificate image should remain an internal fact-checking record rather than a public project image.

What the installation scope included

Removal and preparation

The written scope included refrigerant recovery, removal and disposal of the former system, a new condenser pad, a gas sediment trap, a Safe-T drain switch, drain insulation and a drain pan. It also included clearing and modifying the condensate drain, trap and vent as required.

Mechanical and refrigerant work

The new horizontal furnace and coil were connected and supported at the existing duct system. The scope included sealing equipment-to-duct transitions, completing required gas-line and furnace-vent modifications, flushing and preparing the existing copper line set, modifying it as required and brazing the refrigerant connections.

‍

Commissioning

The contracted scope called for a dry-nitrogen pressure test at 250 psi for at least 15 minutes, evacuation below 500 microns, system startup and operational testing. These figures describe the contracted/completed scope supplied for publication; they should not be presented as independently witnessed measurements unless the final commissioning sheet is added to the project record.

Completed installation and warranty boundaries

The new indoor and outdoor equipment was installed on October 11, and the system was run and tested after completion according to the supplied work record. No documented temperature split, static pressure, airflow, humidity result or utility savings was provided for publication.

Greentech’s proposal includes a complimentary three-year/1,095-day contractor labor warranty, subject to the written exclusions and non-transferability terms. The proposal also describes registration-dependent manufacturer coverage. Registration deadlines, eligibility, exclusions and the complete manufacturer warranty terms control the actual coverage.

What McKinney homeowners can learn from this case

• Ask for the exact equipment combination, not only a brand and nominal tonnage.
• Ask for the matched-system reference and certified rating.
• Review the entire installation scope, testing steps and warranty before approval.
• Treat nominal tonnage and AHRI-certified capacity as related but different specifications.
• Ask the contractor to separate confirmed findings from assumptions and optional upgrades.
• Do not assume that equipment selected for one McKinney house is correctly sized for another.

For local service information, visit Greentech’s McKinney HVAC service page or review A/C replacement options in McKinney.

Sources and verification

This case was prepared from Greentech’s project estimate, equipment information, installation photographs and AHRI Certified Reference Number 214856170. Manufacturer-family details were checked against Daikin’s official DC4SE, CHPTA and DR80SN product pages. The exact project combination and ratings come from the project’s AHRI certificate, not from a product-family maximum. Customer identity, street address, estimate identifiers, prices, serial numbers and private document links are excluded.

Frequently asked questions

What HVAC system was installed in this McKinney 75070 home?

Greentech installed a nominal 3.5-ton Daikin R-32 straight-cool air conditioner with a horizontal evaporator coil and an 80,000-BTU-input, single-stage 80% AFUE gas furnace. The models are DC4SEA4210AA, CHPTA4830C3AA and DR80SN0805CXAA.

What efficiency does AHRI reference 214856170 certify?

AHRI reference 214856170 rates the listed combination at 39,000 BTUH certified cooling capacity, 15.2 SEER2 and 12.0 EER2.

Why is this called a 3.5-ton system if AHRI lists 39,000 BTUH?

The 42,000-BTU outdoor model belongs to the nominal 3.5-ton product size. AHRI reports the certified cooling capacity of the exact outdoor unit, indoor coil and furnace combination under standardized test conditions.

What did the replacement estimate identify before approval?

The project estimate identified the proposed model numbers, AHRI reference, rated performance, removal and installation scope, testing steps and labor-warranty terms. Customer and price details should remain redacted in public images.

Did this project include a Manual J calculation, rebate, permit or inspection result?

The supplied publication record does not document a Manual J report, incentive approval, permit or final-inspection result. This case therefore makes none of those claims.

What warranty applies to this installation?

The proposal includes a complimentary three-year/1,095-day contractor labor warranty subject to its written exclusions and non-transferability terms. Manufacturer coverage depends on registration, eligibility and the complete manufacturer warranty.

Request a documented HVAC replacement estimate

If your system is not cooling and replacement is being discussed, request a written Greentech assessment that identifies the diagnosis, equipment, installation scope, warranty and total authorized price before work begins.

Primary CTA: Request a Transparent HVAC Estimate
Secondary CTA: Get an Independent HVAC Second Opinion

Learn more about A/C replacement in McKinney and professional A/C installation.

About the author

Siwei (Lucas) Chen
Chief Technology Officer | Greentech Engineering Heating & Air Conditioning — DFW HVAC

Siwei (Lucas) Chen applies an engineering-based, data-first approach to residential HVAC system design, diagnostics, airflow measurement, equipment selection and duct-system optimization across Dallas–Fort Worth. He holds a B.S. in Mechanical Engineering from Virginia Tech.

Lucas completed ACCA’s Residential Design for Quality Installation Course, which covers residential design procedures associated with ACCA Manuals J, S, T and D. He is also an NCI Certified Residential Air Balancer and NCI Certified Duct System Optimization Specialist.

Technical facts last verified October 14, 2026.

‍