TOOL-001 · Engineering Mode · V1.0

Cooling & Heating Load Planner

Estimate peak cooling and heating demand with explicit design inputs, traceable rules, pinned sources and a report generated from the same Structured Result used by the UI.

Estimator scope: L1/L2 design-point engineering estimator. No hidden U-values, solar, gains, airflow, humidity or sizing margin defaults are applied.

Result units

Engineering inputs

Design conditions & loads

Canonical SI input

Project / zone

Project name (local only)Zone nameFloor aream²Ceiling heightmVolume overridem³

Indoor design

Cooling dry-bulb°CCooling RH%Heating dry-bulb°C

Outdoor design

Cooling dry-bulb°CHeating dry-bulb°CCooling moisture methodOutdoor cooling RH%Pressure sourceStation pressurePa

Envelope surfaces

Surface 1

TypeAream²U-valueW/m²·KAdjacent conditionOrientation

Fenestration / solar

Solar is intentionally not calculated unless SHGC, design irradiance and external shade factor are all explicit.

Glazing 1

Aream²U-valueW/m²·KSHGCDesign solar irradianceW/m²External shade factorOrientation

Internal gains

People countSensible / personW/personLatent / personW/personPeople diversity factorLighting methodLighting power densityW/m²Lighting use factorEquipment sensibleWEquipment latentWEquipment use factor

Outdoor air & infiltration

Ventilation methodVentilation dry-air mass flowkg dry air/sInfiltration methodInfiltrationACH

Options

Credit sensible internal gains for heatingPeople sensible + lighting + equipment sensible only. Solar is never credited in V1.Sizing margin%

No hidden engineering defaults are injected.

Formulas, source and scope

Conduction q = U·A·(T_adjacent − T_indoor); cooling demand keeps the positive part and heating demand keeps the positive reverse. People gain = count × per-person sensible/latent × diversity. Lighting and equipment use the entered power × use factor. Solar, only when SHGC, irradiance and shade are all present: q = A·SHGC·I·shade. Outdoor-air cooling uses dry-air mass flow × moist-air enthalpy difference from the pinned PsychroLib adapter; sensible split uses (1006 + W·1860)·ΔT, with 1006 and 1860 as engine constants J/(kg·K). Sized load = base × (1 + margin%/100).

Pinned in this repo: PsychroLib 2.5.0 (SRC-PSYCHROLIB-2.5.0), EnergyPlus Engineering Reference 26.1.0 (SRC-ENERGYPLUS-ENGREF-26.1), project method V1.0 (SRC-PROJECT-METHOD-001). These pins are implementation and cross-check records, not a claim of code certification.

FAQ

Does a result certify a code load calculation?

No. It is an L1/L2 design-point estimate with explicit inputs. Confirm climate, schedules and construction data before design use.

Where is a reproducible case?

Use Load reviewed example, then Calculate. The same structured result feeds the on-page breakdown and the print report.

Use this planner to screen peak cooling and heating loads from transparent design inputs before detailed energy modeling. Inputs cover envelope, internal gains and outdoor conditions; outputs are load totals with assumption trails. Engineering formulas remain pinned in the tool engine and are not altered for marketing. Results are for concept and early design review only.

Worked screening path: load a reviewed example, run Calculate, then inspect cooling/heating totals and warnings. Confirm climate data, schedules and construction U-values against project sources before relying on numbers.

Air-state process check → · Outdoor-air screening → · Chilled-water scenario → · About method & privacy →