# A Queen Creek Homeowner Got Four Quotes Ranging From 4-Ton to 5-Ton - We Ran the Manual J and Got 3-Ton | Comfort Pros Blog > Three of four quotes said the existing 4-ton was right-sized or undersized. The Manual J said otherwise. The new 3-ton 16-SEER variable speed has held up to a Phoenix summer on less electricity than the unit it replaced. URL: https://www.comfortprosaz.com/blog/queen-creek-whole-home-ac-replacement-manual-j/ Last-Modified: 2026-08-06 Author: Armen Vartanian Case Study # A Queen Creek Homeowner Got Four Quotes Ranging From 4-Ton to 5-Ton - We Ran the Manual J and Got 3-Ton Three of four quotes said the existing 4-ton was right-sized or undersized. The Manual J said otherwise. The new 3-ton 16-SEER variable speed has held up to a Phoenix summer on less electricity than the unit it replaced. Armen Vartanian · August 6, 2026 · 5 min read ![A Queen Creek single-story tract home with an aging condenser unit in the side yard, representing a home where the existing unit was actually oversized for the load](/images/featured/candid-photo-of-a-chandler-single-story-tract-home.webp) The homeowner had four quotes on her kitchen table. Three of them said the existing 4-ton system was right-sized or undersized for her Queen Creek single-story. One said the system was oversized and the right replacement was a 3-ton. The numbers ranged from $7,800 for a 4-ton replacement to $11,400 for a 5-ton replacement that included new ductwork. We ran the Manual J. The total cooling load came back at **28,400 BTU**. With a 0.9 latent sensible heat ratio and a 1.1 sizing factor for Phoenix design conditions, the right equipment size is a 3-ton. We quoted a 3-ton 16-SEER variable speed system, installed it, and the homeowner has now run it through two Phoenix summers. The new system has held up to the same heat load the old system struggled with. It uses less electricity than the old system at the same thermostat setting. The homeowner’s summer electric bill is lower than it was with the 4-ton. ## What the Other Quotes Were Sizing To Three of the four quotes were sizing to the existing 4-ton system. “The house was on a 4-ton, so the house needs a 4-ton.” That logic is backward. The right size for the house is the size the house actually needs, not the size the existing equipment happens to be. The existing 4-ton might have been right-sized in 2008 when it was installed, or it might have been oversized by the rule-of-thumb calculation the original installer applied. We did not know without running the calculation. The fourth quote was sizing to the rule of thumb - about 500 square feet per ton in a hot climate, applied to the 1,950 square foot house, which gives roughly 3.9 tons, rounded up to 4. Three of the four quotes were sizing to existing equipment. One was sizing to a rule of thumb. None of them were sizing to a load calculation. ## What the Manual J Actually Said The inputs that mattered for this house. **Floor area and ceiling height.** 1,950 square feet, 9-foot ceilings throughout. Single-story, slab-on-grade, with the attic above and the garage attached on the north side. **Orientation and glass.** South-facing great room with a 12-foot by 8-foot sliding glass door and a 6-foot by 4-foot window. East-facing master bedroom with a 6-foot by 4-foot window. West-facing kitchen with a 4-foot by 3-foot window. North-facing rooms have minimal glass. **Construction.** Standard 2008 tract construction. R-13 wall insulation, R-30 attic insulation, radiant barrier on the attic decking. Double-pane low-E glass on all windows and the sliding door. **Infiltration.** Smoke pencil test at the door and window frames. Conservative infiltration rate based on what we measured. **Internal gains.** Standard household - refrigerator, dishwasher, television, lighting, two adults, no cooking appliances adding significant load beyond the kitchen range hood. **Design temperature.** Phoenix design cooling temperature at the 1 percent level. The total sensible cooling load came back at 24,800 BTU. Add the latent load from infiltration and internal gains, factor for design conditions, and the total cooling load was 28,400 BTU. A 3-ton system (36,000 BTU nominal, with a typical sensible capacity around 28,000 to 30,000 BTU at design conditions for a modern system) matches this load. A 4-ton system (48,000 BTU nominal) would have a sensible capacity around 38,000 to 40,000 BTU at design conditions. That is meaningfully more capacity than the load. The system would short cycle, run inefficiently at part load, and dehumidify less effectively. ## What the Homeowner Got From Right-Sizing **Lower equipment cost.** A 3-ton system is less expensive than a 4-ton system. The price difference on this install was about $1,200. **Lower operating cost.** A 3-ton variable speed system modulating to match the load uses less electricity than a 4-ton system cycling on and off. The homeowner’s summer electric bill dropped by about 18 percent after the install, compared to the previous summer with the 4-ton system running. **Better dehumidification.** A right-sized variable speed system runs longer at lower capacity, which extracts more moisture from the air. The homeowner noticed the house felt less clammy at the same thermostat setting. **Quieter operation.** A 3-ton variable speed system at part load is quieter than a 4-ton system cycling on and off. The homeowner noticed the difference immediately. **No new ductwork needed.** The existing ductwork was sized for the 4-ton system. Right-sizing to a 3-ton meant the existing ducts were now over-sized for the new system, which is a comfortable position to be in. A 4-ton or 5-ton replacement would have required either ductwork modifications or running the system at lower static pressure than rated. ## What Right-Sizing Cost Versus the Wrong Sizes | Quote | Equipment | Equipment cost | Install cost | Total | | --- | --- | --- | --- | --- | | Quote 1 | 4-ton 14-SEER single stage | $3,800 | $4,000 | $7,800 | | Quote 2 | 4-ton 16-SEER two stage | $4,600 | $4,800 | $9,400 | | Quote 3 | 5-ton 16-SEER variable speed | $5,800 | $5,600 | $11,400 | | Quote 4 (our Manual J-based quote) | 3-ton 16-SEER variable speed | $4,400 | $4,000 | $8,400 | The 3-ton variable speed was not the cheapest quote on equipment. It was the cheapest quote on total installed cost. The 4-ton two stage at $9,400 had a better equipment efficiency rating (16 SEER) than the 3-ton variable speed, but the equipment cost was higher and the operating cost difference was not enough to make up for the lost efficiency from oversizing. We were not the lowest equipment bid. We were the lowest total bid for the right-sized system. The homeowner signed with us for that reason. ## What We Tell Homeowners Considering AC Replacement Three things to verify before signing an AC quote. **The contractor should have run a Manual J.** Not a rule of thumb, not a square-footage calculation, not a “same size as the existing unit.” The Manual J is the standard. If the contractor cannot show you the calculation, ask why. **The quote should specify the equipment size, model, and efficiency rating.** A quote that says “3-ton” or “4-ton” without a model number and a SEER rating is not a quote - it is a placeholder. The equipment specification determines the operating cost for the next 15 years. **The quote should include ductwork evaluation.** A right-sized system on poorly sealed or poorly designed ducts is leaving efficiency on the table. The contractor should have inspected the ducts, measured the static pressure, and identified any ductwork modifications that the new system requires. If any of those three are missing from the quote, the install is being undersold. The number on the quote reflects what is being left out. **If you are considering AC replacement and want a quote based on a real Manual J** - request a load calculation and quote [/ac-installation/ →](/ac-installation/) or read more about what a Manual J load calculation actually covers [/guide/manual-j-load-calculation/ →](/guide/manual-j-load-calculation/) . ![Armen Vartanian](/images/squares/author-armen-vartanian.webp) Armen Vartanian [/about/#armen-vartanian →](/about/#armen-vartanian) Owner & Founder, Licensed HVAC Contractor Founder of Comfort Pros AZ and CA, 30+ years in HVAC and plumbing across Arizona and Southern California. ✓ AZ ROC 364742 - Specialty Dual CR-39, Air Conditioning and Refrigeration #hvac #ac-installation #queen-creek #manual-j #right-sizing ## More From the Trucks ![Interior of a 1962 California bungalow with original plaster walls, representing a Burbank home where three pinhole leaks in eighteen months led to a whole-home PEX-A repipe](/images/misc/interior-of-a-pre-1960-california-bungalow-with-a-.webp) Case Study Sep 12, 2026 ### A 1962 Burbank Bungalow, On Its Third Pinhole in Eighteen Months - The Whole-Home Repipe We Did in PEX-A Three pinhole leaks in galvanized and soft copper in eighteen months. The fourth one was already forming. We repiped the whole house in PEX-A in four days, with the drywall patched back better than it was. Read the story [A 1962 Burbank Bungalow, On Its Third Pinhole in Eighteen Months - The Whole-Home Repipe We Did in PEX-A →](/blog/burbank-whole-home-repipe-pex-a-1960s-copper/) ![A wall-mounted ductless mini-split head installed high on a stucco wall above a garage workbench, with a slim white line-set cover running down to the outdoor unit](/images/featured/wall-mounted-mini-split-head-above-a-garage-workbe.webp) Case Study Sep 10, 2026 ### Adding AC to a La Crescenta Casita - A Ductless Mini-Split in One Day A converted garage casita in the Crescenta Valley foothills had no AC, no ductwork, and a tight electrical panel. A single-zone ductless mini-split solved all three - installed in one day, no drywall opened. Read the story [Adding AC to a La Crescenta Casita - A Ductless Mini-Split in One Day →](/blog/la-crescenta-ductless-mini-split-casita/) ![A restored Pasadena driveway and front yard after a trenchless sewer liner was installed, showing that no excavation was needed for the sewer repair](/images/hero/restored-driveway-and-landscaping-after-a-trenchle.webp) Case Study Sep 10, 2026 ### Pasadena Sewer Lateral: We Lined 48 Feet of Pipe Under a 50-Year-Old Driveway Without Digging A 1968 clay sewer lateral with root intrusion at every joint. The homeowner was told she needed a $22,000 excavation. Cured-in-place lining sealed every joint from the inside and saved the driveway. Read the story [Pasadena Sewer Lateral: We Lined 48 Feet of Pipe Under a 50-Year-Old Driveway Without Digging →](/blog/pasadena-sewer-lateral-cured-in-place-lining/) ![Comfort Pros HVAC technician greeting a homeowner at the front door](/images/hero/candid-wide-photo-of-a-technician-shaking-hands-wi.webp) Same-day appointments available ## Ready for an Honest Number? Run a real load calculation online, or call the team in your state. Flat-rate pricing either way, and nobody shows up to sell you something bigger than you need. Get Your TrueQuote [https://quote.comfortprosaz.com →](https://quote.comfortprosaz.com) (480) 435-2334 [tel:+14804352334 →](tel:+14804352334) Flat-rate pricing, no upsells Parts and labor warranty Licensed in AZ and CA California team: (818) 690-7951 [tel:+18186907951 →](tel:+18186907951) · Text us: (818) 489-2826 [sms:+18184892826 →](sms:+18184892826)