Energy Academy
Level 1: Foundations/Mass & Energy Balances
Level 116 lessons · 138 min

Mass & Energy Balances

The universal method behind every audit, diagnosis and M&V calculation: drawing a boundary, tracking what goes in and out, and never losing a kWh.

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01Conservation Principles & System Boundaries

  1. ▶The Conservation Laws: Mass & EnergyWhy nothing is created or destroyed — the first law restated as a practical accounting tool, not just theory.9 min
  2. ▶Defining the System: Boundaries & Control VolumesDrawing the line around what you're analysing — open vs closed systems, steady-state vs transient — and why the boundary you choose changes the answer.10 min
  3. ▶Building Your First Balance: In = Out + LossesThe general balance equation, a black-box worked example, and the habit of always accounting for 100% of what goes in.10 min
  4. ▶Conservation Principles CheckQuiz on conservation laws, boundaries and the general balance equation.5 min

02Mass Balances in Practice

  1. ▶Conservation of Mass & Material FlowMass in = mass out + accumulation; units, density and flow-rate conversions for steady-flow processes.9 min
  2. ▶Worked Example: A Combustion Mass BalanceBalancing fuel and air for methane combustion — stoichiometric air, excess air, and why boilers never run at the theoretical ratio.11 min
  3. ▶Worked Example: A Moisture (Psychrometric) BalanceTracking water vapour through an air-handling unit — where dehumidification energy actually goes.10 min
  4. ▶Mass Balances CheckQuiz on mass conservation, combustion stoichiometry and moisture balances.5 min

03Energy Balances Across Real Systems

  1. ▶Worked Example: The Boiler Energy BalanceFuel in, useful heat out, and where the rest goes — flue losses, casing losses, blowdown.10 min
  2. ▶Worked Example: The Steam & Condensate BalanceEnthalpy in, enthalpy out — tracking sensible and latent heat through generation, distribution and return.10 min
  3. ▶Worked Example: The HVAC Sensible & Latent BalanceSplitting a cooling load into sensible and latent components, and why over-dehumidifying wastes energy.10 min
  4. ▶Energy Balances CheckQuiz on boiler, steam and HVAC energy balances.5 min

04Visualising, Grading & Applying Balances

  1. ▶Sankey Diagrams: Seeing Where the Energy GoesTurning a balance into a picture — reading and building a Sankey diagram from your own numbers.9 min
  2. ▶The Quality of Energy: An Introduction to ExergyWhy a kWh of electricity and a kWh of lukewarm waste heat aren't worth the same — grading energy by its ability to do useful work.9 min
  3. ▶Putting It Together: Using Balances to Find SavingsA combined mass-and-energy balance on a real process, and how it becomes the backbone of an energy audit.11 min
  4. ▶Balances in Practice CheckQuiz on Sankey diagrams, energy quality and applying balances to find savings.5 min