HVAC Load & Sizing Blog
Guides, worked examples, and straight answers on HVAC load calculation and equipment sizing — written to pair with our free calculators.
- What Is HVAC Load Calculation?A plain-English explanation of what an HVAC load calculation is and why it decides the size of every system.Read guide
- How to Calculate HVAC Load, Step by StepThe exact steps, inputs, and formulas to calculate heating and cooling load for a home.Read guide
- How to Measure Your Home for HVAC SizingA measuring checklist that gets you accurate inputs before you run a load calculation.Read guide
- HVAC Load Calculation Example: A Worked WalkthroughFollow a complete load calculation for a real home, number by number, to a final tonnage.Read guide
- The HVAC Load Calculation Formula, ExplainedThe core load formulas — sensible, latent, conduction, and infiltration — with what each term means.Read guide
- What Size AC Do I Need? A Sizing Chart by Sq Ft and ClimateA square-footage-by-climate AC sizing chart — and why the rule of thumb often gets it wrong.Read guide
- What Size Furnace Do I Need? BTU by Home SizeFurnace BTU sizing by home size and climate, including the AFUE input-vs-output gap.Read guide
- What Size Heat Pump Do I Need? A Sizing GuideHeat pump sizing done right — balance point, cold-climate derating, and dual-fuel cutoffs.Read guide
- What Is Manual J? The Complete GuideThe ACCA Manual J standard explained — what it covers and why codes require it.Read guide
- Manual J vs Manual S vs Manual D, ExplainedHow load (J), equipment selection (S), and duct design (D) work together.Read guide