HVAC Load & Sizing Blog
Measure your home, check heating and cooling calculations, and review equipment capacity with worked examples and Manual J report checklists.
- What Is HVAC Load Calculation?Understand the three design loads, their units, and the building inputs needed before selecting equipment.Read guide
- How to Calculate HVAC Load, Step by StepCollect inputs, check heating and moisture arithmetic, and separate load calculations from equipment selection.Read guide
- How to Measure Your Home for HVAC SizingA room and envelope survey checklist with checked area, volume, and opening calculations.Read guide
- HVAC Load Calculation Example: A Worked WalkthroughA hypothetical 2,000 sq ft example with explicit assumptions, heating subtotals, and cooling capacity checks.Read guide
- The HVAC Load Calculation Formula, ExplainedCheck heat-transfer equations, units, and component arithmetic without adding hidden sizing margins.Read guide
- What Size AC Do I Need? Load and Capacity ChecksConvert cooling loads to tons, compare component capacities, and check existing ducts before replacing an AC.Read guide
- What Size Furnace Do I Need? Input and Output BTUCheck rated furnace output, AFUE estimates, stages, and blower airflow against a documented heating load.Read guide
- What Size Heat Pump Do I Need? A Sizing GuideCheck summer moisture performance, winter output, balance point, and backup capacity for the intended controls.Read guide
- What Is Manual J? Inputs, Loads, and Report RequirementsWhat a residential Manual J report contains and how to review its inputs before equipment selection.Read guide
- Manual J vs Manual S vs Manual D, ExplainedThe load, equipment, and duct deliverables, with capacity examples and checks between each design step.Read guide
- 7 Possible Signs Your AC Is OversizedSeven signs that can point to an oversized AC, the other faults that cause them, and how to confirm with a load check.Read guide
- Heat Pump vs Furnace: Which Is Right for You?Cost, climate, efficiency, and comfort compared — plus how to choose for your home.Read guide
- HVAC Replacement Cost: Compare Quotes and ScopeCompare replacement quotes on equal scope: equipment, ducts, electrical work, warranties, and confirmed incentives.Read guide
- What Size Mini Split Do I Need? Loads and CapacitySize mini-split heads from room loads, minimum output, and winter capacity instead of floor area alone.Read guide
- AC Tonnage per Square Foot: Chart and LimitsWhat square-feet-per-ton rules really imply, with checked conversions, and why a load calculation should decide.Read guide
- Heat Load Calculation Methods ComparedArea estimates, Manual J, and ASHRAE cooling methods compared by inputs, accuracy, and when to use each.Read guide
- Heat Load Units: BTU/h, Watts, kW, and TonsConvert BTU/h, watts, kW, and tons correctly, and keep capacity, electrical input, and energy separate.Read guide
- Block Load vs Room-by-Room Manual JWhy equipment is sized from the block load and ducts from room loads, with a checked room-airflow example.Read guide
- Is Manual J Required for an HVAC Permit?How to find out whether your jurisdiction requires a Manual J, and what an acceptable report includes.Read guide
- AC Short Cycling: Causes and FixesThe real causes of short cycling — oversizing included — and how to fix each.Read guide
- Is a Bigger AC Better? Why Oversizing BackfiresBigger isn't better — what oversizing actually costs you.Read guide
- What Is SEER2? Ratings and Savings ExplainedWhat SEER2, EER2, and HSPF2 measure, how to verify matched ratings, and how to estimate savings.Read guide
- Mini Split vs Central Air: Full ComparisonDuctless vs central AC on cost, efficiency, install, and zoning.Read guide
- How to Size Ductwork: A Practical GuideSize ducts by CFM and friction loss — the friction-rate method, step by step.Read guide
- HVAC Static Pressure ExplainedWhat static pressure is, why high readings hurt, and how to measure it.Read guide
- IECC Climate Zones: County Lookup and HVAC LimitsHow to find your county's IECC climate zone, and why it does not replace local design weather.Read guide
- HVAC Design Temperature Explained: 1% and 99%Why load calcs use 1% and 99% design temps, not record highs and lows.Read guide
- Heat Pump Payback: Costs, Savings, and AssumptionsEstimate payback from local quotes and modeled operating costs, with sensitivity checks and no expired federal credit.Read guide
- Heat Pump Tax Credits in 2026: What Ended and RemainsThe federal 25C and 25D credits ended after 2025. What remains: state rebates, utility programs, and how to verify them.Read guide
- HVAC Load Calculation Software: How to ChooseEvaluate calculation tools, report exports, approval, offline use, and data ownership before choosing software.Read guide
- HVAC Load Calculation Training: Paths and PracticeTraining paths through ACCA, software providers, and manufacturers, plus exercises that build real skill.Read guide
- HVAC Load Calculation Service: Scope and Report ReviewWhat a paid Manual J, S, and D service should deliver, what to send the designer, and red flags in reports.Read guide
- Questions to Ask Your HVAC ContractorThe questions that separate a right-sized install from an upsell.Read guide
- How to Verify a Contractor's HVAC QuoteCheck a quote for proper sizing and scope before you sign.Read guide
- How to Read a Manual J Load Calculation ReportReview assumptions and load summaries, reconcile room totals, and keep a useful PDF record for bids.Read guide