Reviewer
Sam Ortiz
HVAC installer, ACCA Manual J trained, 9 years field work
Sam is an HVAC installer working in the southwest US. He has put in roughly 800 residential systems across nine years on the truck, mostly heat pumps and split-system air conditioners on retrofit jobs, plus a meaningful share of new construction in production homes. He completed ACCA's Residential HVAC Design certificate program, which covers Manual J Eighth Edition load calculations, Manual S equipment selection, and Manual D duct sizing across the three-day in-person course taught by ACCA instructors.
Most of Sam's day is split between two tasks: walking new houses with a tape measure and a window count to build a real Manual J before quoting, and pulling out 20-year-old oversized condensers to replace them with right-sized variable-capacity equipment. He has watched the same pattern repeat for years, where a contractor quotes a 5-ton replacement for a 3-ton house because that is what is already there, and the homeowner ends up with humidity complaints inside a year. The sizing calculators on this site exist specifically to give homeowners a second opinion before they sign that quote.
Sam reviews the load-calc and equipment-sizing tools (Manual J, AC tonnage, HVAC tonnage by sqft, heat loss, R-value insulation, water heater sizing, dehumidifier sizing, humidifier sizing) and the gas pipe sizing calculator since most of the southwest install base runs on natural gas backup. His sign-off means a real installer would pull a permit with the numbers the calculator returns.
Tools reviewed by Sam
Every tool listed below was reviewed by Sam Ortiz against the published code, standard, or manufacturer data it implements. Sam signs off on the math, the inputs that drive it, and the edge cases the result panel flags.
Comparison guides reviewed by Sam
Side-by-side comparisons fact-checked by Sam 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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Best humidifier: Levoit vs Vicks vs Honeywell vs Aprilaire
Room vs whole-house first, then the best brand for you: Levoit for smart, Honeywell for hard water, Vicks for colds, Aprilaire for the whole house.
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Rheem vs AO Smith water heater
The two biggest US water heater brands head to head. Tank, tankless, and hybrid heat pump differences, warranty fine print, and the plumber-default reality.
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Two-stage vs modulating furnace
Three burner tiers, three price points. What the $1,000 and $3,000 premiums actually buy in comfort, noise, and dust, and the honest gas-savings reality.
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Tankless vs tank water heater
Install cost, lifespan, DOE efficiency math, and the cases where each one wins for water heating.
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Rinnai vs Navien
The two tankless brands plumbers quote. Warranty fine print, built-in recirculation, what breaks on each, and which one your area can service.
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Electric vs gas water heater
Install price, monthly bill math by region, recovery rate, lifespan, and where heat pump units fit.
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Heat pump water heater vs gas
Install cost, operating cost, the HEAR rebate stack that drops net install to $500 to $2,000, and where the heat pump unit will not work.
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Swamp cooler vs AC
For dry climates. Install cost by city, wet-bulb math, water consumption, and the dual-system play that cuts summer cooling bills 30 to 50 percent.
Troubleshooting guides reviewed by Sam
Diagnostic walkthroughs Sam 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 Sam
HVAC explainers covering the questions homeowners ask most, fact-checked by Sam against field experience and published code.
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What size AC do I need?
Why the square-footage rule of thumb oversizes most homes, why a bigger AC cools worse and costs more, what really decides the right size, and how to make sure a contractor sizes your new unit with a real load calculation instead of a guess.
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Heat pump water heater: how it works and what owning one is like
An electric tank with a heat pump bolted on top. How the refrigerant cycle moves heat into the tank, daily ownership reality, side effects, and what tends to break 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.