Chapter 1: HVAC System Fundamentals

HVAC system fundamentals infographic showing a house cutaway with thermostat, indoor air handler, ductwork, outdoor unit, and refrigerant system, plus a five-step component connection diagram

Two-story residential cutaway showing an energy recovery ventilator, evaporator coil, and color-coded supply air, return air, fresh air, and exhaust air paths throughout the home

Annotated whole-house HVAC diagram with color-coded return air, supply air, refrigerant, and exhaust air paths traced through every room, plus a six-step how-it-all-works callout

Energy recovery integration schematic showing an ERV rotary enthalpy wheel in series with an AHU

Fundamental feedback control loop diagram showing sensor, controller, actuator, process, and sensor again in sequence, with a PID algorithm equation and a worked HVAC room temperature control example

Simple HVAC control flowchart showing start, scheduled occupancy decision, system on, call for cooling decision, cooling mode, fan only idle, system off, and end, with a legend and logic summary

Electrical fundamentals for HVAC infographic covering Ohm

Simplified HVAC control sequence diagram showing a temperature sensor, controller, actuator, and process heating coil connected in a loop with a feedback path back to the sensor