Heat load calculation is the unglamorous core of HVAC design — get it wrong and you either oversize equipment (wasting capital and degrading part-load efficiency) or undersize it (failing on the design day). This video walks through the actual psychrometric formulas engineers use to size systems, not just hand-wavy concepts.

Expect coverage of sensible heat (Q = 1.08 × CFM × ΔT in IP units), latent heat from moisture loads, and total heat via enthalpy differences (Q = 4.5 × CFM × Δh). The interesting part is how these formulas connect to the psychrometric chart — understanding why the constants are what they are (air density, specific heat, the 1.08 / 4.5 / 0.68 coefficients) is what separates someone copying formulas from someone who can troubleshoot a system that isn't behaving.

The promise of worked examples is what elevates this above the typical "intro to HVAC" content. Real load calcs involve choosing design conditions, accounting for solar gain, internal loads (people, lights, equipment), infiltration, and ventilation requirements per ASHRAE 62.1 — and then balancing sensible vs. latent ratios to pick coil conditions.

From a 954-subscriber MEP-focused channel, this is the kind of tutorial that's genuinely useful for early-career mechanical engineers or anyone moving from theory into actual building system design.