Lesson 1Two likely causes of floor-to-floor temperature differences: airflow imbalance (duct/vent, registers) and refrigerant or compressor performance issuesThis section explains the two most common causes of floor‑to‑floor temperature differences: airflow imbalance from duct or register issues, and problems with refrigerant charge or compressor performance that reduce system capacity.
Identify symptoms of airflow imbalance by floorCheck for closed, blocked, or misdirected registersRecognize signs of low capacity or poor compressionRelate duct design limits to current building loadsDecide when imbalance needs design reviewLesson 2Confirming causes: airflow measurements, temperature splits, return air assessments, refrigerant charge checks (when qualified)This section explains how to confirm root causes of comfort issues using airflow readings, temperature splits, return air checks, and, when qualified, refrigerant charge evaluation, ensuring data supports any recommended repairs or contractor calls.
Measure supply and return airflow at key zonesCheck temperature split across evaporator coilAssess return air paths, blockages, and bypassesInterpret static pressure and fan performance dataCoordinate refrigerant checks with licensed staffLesson 3Safe tasks for technician: filter change, register balancing, condensate clearing, visual rooftop checksThis section defines safe, typical tasks for building technicians, including filter changes, register and diffuser balancing, clearing condensate drains, and performing visual rooftop inspections while following site safety and lockout procedures.
Replace and label filters to building standardsAdjust supply registers and diffusers for balanceClear and test condensate pans, traps, and drainsPerform visual rooftop unit and curb inspectionsDocument findings and escalate issues appropriatelyLesson 4Initial rooftop unit checks: power, disconnect, visible refrigerant/oil leaks, condensate drainageThis section covers the first checks at a rooftop unit when a comfort complaint is reported, including verifying power and disconnects, scanning for oil or refrigerant stains, and confirming proper condensate drainage and general unit condition.
Verify main power, fuses, and disconnect positionInspect panels, gasketing, and unit anchoringLook for oil stains and refrigerant leak indicatorsCheck condensate pans, traps, and drain outletsNote unusual noises, vibration, or fan behaviorLesson 5Preventive maintenance schedule and best practices (filter frequency, seasonal tune-ups, condensate drain care)This section presents a preventive maintenance plan for rooftop units and ductwork, including filter replacement intervals, seasonal tune‑ups, coil and drain care, and documentation practices that reduce breakdowns and comfort complaints.
Set filter change frequency by load and environmentPlan seasonal cooling and heating tune‑upsClean coils, drain pans, and traps routinelyInspect belts, bearings, and electrical terminationsMaintain detailed PM logs and service historyLesson 6Thermostat and control verification: setpoint checks, zoning conflicts, sensor placement and calibrationThis section focuses on thermostat and control verification, including checking setpoints, schedules, zoning conflicts, sensor placement, and calibration so that control issues are not mistaken for equipment or ductwork failures.
Confirm thermostat modes, setpoints, and schedulesCheck zoning dampers for proper responseEvaluate sensor placement and draft influencesPerform basic thermostat and sensor calibrationReview BAS trends for overrides and conflictsLesson 7Work requiring licensed HVAC contractor: refrigerant handling, compressor or coil replacement, major duct modifications, electrical motor replacementsThis section clarifies which tasks must be handled only by licensed HVAC contractors, emphasizing legal requirements, refrigerant regulations, major component replacement, and complex duct or electrical work that exceed a building technician’s permitted scope.
Regulations for refrigerant recovery and chargingCompressor, condenser, and evaporator coil replacementMajor duct resizing, rerouting, or new trunk linesReplacement of condenser, blower, and VFD motorsPermits, inspections, and documentation needsLesson 8Post-repair validation: temperature mapping, airflow measurements, runtime and short-cycling checks, tenant comfort verificationThis section explains how to verify that repairs or adjustments solved comfort issues, using temperature mapping, airflow checks, runtime observations, and tenant feedback to confirm stable operation without short‑cycling or new imbalances.
Map temperatures by floor and representative zonesRecheck airflow and diffuser throw after changesMonitor runtimes and watch for short‑cyclingConfirm condensate drainage and coil conditionsGather tenant feedback and update service recordsLesson 9Basic routine checks: filter condition, blower operation, refrigerant pressures, compressor and fan motorsThis section outlines the routine checks a technician performs before deeper diagnostics, focusing on filters, blower operation, basic electrical checks, and observing refrigerant pressures without adjusting charge unless properly qualified and authorized.
Inspect and document filter type and conditionVerify blower rotation, speed, and noise levelsCheck blower belts, pulleys, and motor mountsObserve suction and discharge pressures, no adjustmentsRecord nameplate data and compare to readingsLesson 10System overview: packaged rooftop unit components and common control schemesThis section introduces packaged rooftop unit components and control schemes, explaining how compressors, fans, coils, dampers, and economizers interact with thermostats, safeties, and building automation systems to maintain comfort.
Identify major mechanical components and layoutUnderstand economizer and outdoor air functionsReview common safety switches and lockoutsOverview of basic thermostat and BAS interfacesTrace typical cooling and heating control sequencesLesson 11Ductwork inspection steps: static pressure checks, visual inspection for leaks, balancing dampers and grille/register checksThis section details ductwork inspection methods, including static pressure readings, visual checks for leaks or damage, and verifying balancing dampers, grilles, and registers so airflow is delivered where the design intended.
Measure supply and return static pressuresInspect ducts for leaks, kinks, and insulation gapsLocate and set balancing dampers correctlyCheck grille and register sizing and orientationDocument deficiencies and recommend corrections
