Reviewer
Dana Okafor
HVAC contractor & estimator, ACCA member, 11 years
Dana owns a small residential HVAC contracting business and has spent eleven years in the trade, the last seven running her own shop. The company writes between 250 and 400 replacement and new-system estimates a year across roughly 60 percent forced-air and 40 percent heat pump installs, with a growing share of mini-split conversions as homeowners electrify. She holds an ACCA contractor membership and stays current on the federal incentive landscape because half her sales conversations now involve heat-pump tax credits and state rebate programs that change quarterly.
Dana is the person on her team who sits down with the kitchen-table spreadsheet and explains why the heat pump option that costs $3,000 more upfront actually costs $2,200 less over five years once the IRA 25C credit, the state rebate, and the lower operating cost on natural gas at current rates are folded in. That sales conversation is the entire reason the cost-and-ROI calculators on this site exist. She reviews them against the quote spreadsheets she actually hands homeowners, so the numbers the calculator returns line up with the numbers a working contractor would put in a proposal.
Dana reviews every tool in the Cost & ROI category (HVAC replacement cost, heat pump vs gas furnace, operating cost, payback period, rebate finder, replace vs repair) plus the thermostat schedule savings calculator. Cost data gets re-verified quarterly against current quote aggregator pulls, and rebate program data gets updated whenever a state launches or pauses its HEAR funding.
Tools reviewed by Dana
Every tool listed below was reviewed by Dana Okafor against the published code, standard, or manufacturer data it implements. Dana signs off on the math, the inputs that drive it, and the edge cases the result panel flags.
System sizing
Comparison guides reviewed by Dana
Side-by-side comparisons fact-checked by Dana against field experience, install quotes, and manufacturer specs. Each guide covers a real homeowner decision, with the install cost ranges, climate fit, and edge cases verified before publication.
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Central AC vs heat pump
Install cost, climate fit, lifespan, rebates, and the cases where each one wins.
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Dual fuel vs heat pump
The cold-climate fork. Balance-point math, install cost by configuration, the HEAR rebate flip, and zone-by-zone operating cost.
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Geothermal vs air-source heat pump
Loop options, payback math by climate, COP efficiency, lifespan, and when air-source still wins.
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Carrier vs Trane
Two quotes on the table. Install cost gap by tier, the warranty registration trap, sound at flagship, and what fails first at year 10.
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Goodman vs Carrier
Budget-vs-premium decision. The $2,000-$6,000 price gap, what the lifetime warranty actually covers, and the 15-year cost-of-ownership picture.
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Trane vs Lennox
Trane runs 12-year registered compressor warranty and a heavier compressor. Lennox tops the SEER2 chart. Which wins at year 12 in your house.
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Rheem vs Trane
The value pick against the premium name. Real installed prices, the unit-replacement vs parts-only warranty split, and when the Trane premium earns it.
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Goodman vs Lennox
The widest gap in HVAC brands: Goodman cheap to buy and fix, Lennox the efficiency ceiling with dealer-locked parts. Why year 8 decides it.
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Amana vs Goodman
Same factory in Waller Texas, two badges. What the price gap actually buys you, the shared-platform model pairs, and when Amana earns the premium.
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Boiler vs furnace
Install cost by fuel, operating cost math, lifespan, comfort, and when a heat pump beats both.
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Single-stage vs two-stage vs variable-speed AC
When two-stage is the value sweet spot, when variable-speed earns its premium, and which tier fits your home.
Troubleshooting guides reviewed by Dana
Diagnostic walkthroughs Dana signed off on against the service calls they actually run. Each page lists the real fix order and what every repair costs.
Guides reviewed by Dana
HVAC explainers covering the questions homeowners ask most, fact-checked by Dana against field experience and published code.
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How to finance heating and air conditioning
A new furnace or AC is a few thousand dollars you did not plan to spend, usually decided fast under pressure. The real ways to pay for it, how to tell a genuine 0% offer from the deferred-interest trap, why the cash price can beat the financed one, and what to ask before you sign.
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How much does a heat pump cost?
Installed price by size and type, why two quotes for the same house differ by thousands, how the refrigerant change moved pricing, and which rebates still apply.
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How much does a gas furnace cost?
Installed price by efficiency, the venting that makes a 96% furnace cost more than an 80%, the new efficiency rule, and whether you can still buy a standard 80% unit.
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How much does central air conditioning cost?
Installed price by size and SEER2 tier, why the refrigerant change raised prices, when you can replace just the condenser, the coil-match catch, and where the federal credit went.
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Should you replace your AC and furnace together?
When to replace both at once, when to split the jobs, what bundling actually saves on labor, and why a new AC will not hit its rating on an old furnace blower.
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Thermostat settings for summer and winter
What to set the thermostat to when you are home, sleeping, away, on vacation, or with a baby in the house. Schedules by season with the dollar math.
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How long does an AC unit last?
Lifespan by equipment type (window, central, mini-split, heat pump, geothermal), what climate does to those numbers, and which components fail first.
How BTU Size uses reviewers
Every tool on BTU Size credits a named technician with field experience in the relevant trade. Reviewers check the math against published code (ACCA, ASHRAE, NEC, NFPA, IECC), against manufacturer engineering data (Carrier, Trane, Mitsubishi, Owens Corning, Slant/Fin), and against the edge cases that show up on real service calls. See the full reviewer roster and methodology.