Lesson 1Fundamentals of heat transfer for HVAC loads: sensible vs latent, conduction, convection, radiation, and solar gainsThis lesson revisits heat transfer basics for HVAC loads, differentiating sensible and latent heat, and examining conduction, convection, radiation, and solar gains in building envelopes and internal sources.
Sensible versus latent heat definitionsConduction through building assembliesConvection at interior and exterior surfacesLongwave and shortwave radiation effectsSolar gains and their interaction with loadsLesson 2Solar heat gain calculations: orientation, shading factors, glass properties, and use of solar heat gain coefficientsThis lesson addresses solar gains via glazing, how orientation and shading alter incident radiation, and applying glass properties and SHGC values to estimate hourly solar cooling loads.
Solar geometry and surface orientationShading devices and shading coefficientsGlass types, coatings, and visible transmittanceUsing SHGC and area to find solar gainsTime-of-day and seasonal solar variationsLesson 3Presenting load calculation worksheets: unit conversions, consistent units (IP), and step-by-step example structureThis lesson describes organising and presenting load worksheets, ensuring consistent IP units, handling conversions, and structuring examples for traceability of assumptions and results.
Standard worksheet layout and sectionsConsistent IP units and common pitfallsKey unit conversions for load workDocumenting assumptions and inputsStep-by-step example presentationLesson 4Equipment and plug load calculations: inventorying, duty cycles, diversity factors, and internal heat distributionThis lesson explains estimating equipment and plug loads from power ratings, duty cycles, and diversity, plus splitting internal heat into sensible and latent parts across zones.
Identifying equipment and plug inventoriesConnected load, demand, and duty cycleDiversity factors for receptacle loadsSensible versus latent equipment gainsZonal distribution of internal equipment heatLesson 5Ventilation and latent loads: outdoor air sensible and latent contributions, using humidity ratios and psychrometric principlesThis lesson concentrates on outdoor air ventilation loads, employing humidity ratios and psychrometrics to divide sensible and latent components, and linking code airflow to cooling and dehumidification loads.
Ventilation airflow from codes and standardsOutdoor and indoor design conditionsHumidity ratio, enthalpy, and psych chartsSensible versus latent ventilation loadsPreconditioning and energy recovery impactsLesson 6Infiltration and unbalanced ventilation: estimating infiltration rates, impact on latent and sensible loadsThis lesson covers how air leakage and unbalanced ventilation influence sensible and latent loads, estimation methods for infiltration, and incorporating stack, wind, and mechanical effects in calculations.
Drivers of infiltration: wind and stackACH, CFM, and envelope leakage metricsEstimating infiltration for load designSensible and latent load from infiltrationUnbalanced ventilation and pressure effectsLesson 7Latent load estimation and psychrometrics: dew point, specific humidity, calculation of latent heat loads from people, ventilation, and processesThis lesson builds latent load estimation with psychrometrics, including dew point, specific humidity, and computing latent heat from occupants, ventilation, and moisture processes in buildings.
Dew point, humidity ratio, and RHPsychrometric chart navigation basicsLatent gains from occupantsLatent loads from ventilation airProcess moisture sources and dehumidificationLesson 8Load calculation approaches: manual cooling load calculations, heat balance overview, and simplified methodsThis lesson introduces primary cooling and heating load methods, from detailed manual calculations and heat balance overviews to simplified rules of thumb, assessing accuracy, inputs, and applications.
Design objectives and required accuracyManual component-by-component methodsHeat balance and radiant-time-series ideasSimplified and rule-of-thumb approachesComparing methods and selecting an approachLesson 9People load calculations: sensible and latent contributions per occupant and per area, using ASHRAE tablesThis lesson details quantifying sensible and latent heat from occupants via ASHRAE tables, factoring activity, clothing, and schedules, and converting to area-based design values.
Metabolic rates and activity categoriesASHRAE tables for sensible and latent gainsOccupancy density and diversity factorsSchedules and peak occupancy selectionConverting per-person to per-area loadsLesson 10Combining loads and safety factors: coincident load summation, diversity, temperature delta selections, and peak load extrapolation from one floor to whole buildingThis lesson demonstrates combining component loads into system designs, applying diversity and safety factors, choosing temperature deltas, and scaling floor results to building-wide peaks.
Coincident versus noncoincident load summationApplying diversity to internal gainsChoosing indoor and outdoor design deltasSafety factors and avoiding oversizingScaling floor loads to whole buildingsLesson 11Envelope heat gains: conduction through walls, roof, windows using UA method and solar heat gain through glazingThis lesson examines envelope heat gains via walls, roofs, and windows with the UA method, including temperature differences, solar exposure, and combining conduction and solar in glazing.
U-values, R-values, and UA calculationsWall and roof conduction with design deltasWindow conduction and frame effectsSolar gains through glazing systemsThermal mass and time lag considerationsLesson 12Lighting load calculations: converting lighting power density to sensible heat, diversity, and control impactsThis lesson explains converting lighting power density and fixture data to sensible heat gains, applying diversity and controls, and accounting for schedules, daylight dimming, and losses.
Lighting power density and fixture dataConverting watts to sensible heat gainsLighting schedules and diversity factorsControls: occupancy and daylight dimmingBallast, driver, and luminaire losses
