Lesson 1Start-up verification: temperature split checks, high/low pressure readings, current draw, vibration and noise inspectionGuides you through first start-up checks, including temperature split, pressure readings, current draw, and inspection for vibration and noise to confirm correct installation and protect the compressor in local conditions.
Stabilising system before measurementsMeasuring supply and return temperature splitReading suction and discharge pressuresMeasuring compressor and fan current drawChecking vibration, noise, and panel fitLesson 2Refrigerant line routing and insulation: line-set lengths and height differences, drain routing and trap placement, insulation materials and thicknessCovers best practices for routing refrigerant lines and drains, managing line-set length and elevation, preventing oil traps, and selecting insulation materials and thickness to avoid sweating and capacity loss in humid climates.
Planning line-set paths and supportsManaging line length and height differenceAvoiding oil traps and sharp bendsDrain line slope, traps, and ventsInsulation material and thickness choicesLesson 3Site selection for outdoor unit: ventilation, noise setback, structural pad or bracket selection, service accessDescribes how to choose an outdoor unit location with adequate airflow, minimal noise impact, solid structural support, and safe, convenient service access for long-term reliability and easy maintenance in dense urban areas.
Clearance for airflow and recirculationNoise, setback, and neighbour impactChoosing pads, brackets, or standsSnow, flooding, and debris concernsPlanning safe technician accessLesson 4Evacuation and vacuum targets: vacuum pump use, target vacuum level (microns), moisture removal rationale and hold testExplains evacuation theory and practice, including pump setup, target micron levels, moisture removal, and standing vacuum tests to verify system tightness before releasing refrigerant into the circuit, crucial for tropical humidity.
Preparing manifold and hoses for vacuumConnecting and sizing vacuum pumpTarget micron levels for new installsPerforming standing vacuum hold testsCommon evacuation mistakes to avoidLesson 5Line connections and joints: proper flare technique, brazing alternatives, wet vs dry connections, leak-prevention practicesDetails correct flare preparation, torqueing, and alternatives such as brazed joints. Emphasises cleanliness, moisture control, and proven leak-prevention practices for long-term reliability of line connections in local installations.
Cutting and deburring copper tubingForming accurate flares and swagesUsing torque wrenches on flare nutsWhen to choose brazed connectionsUsing sealants and gaskets correctlyLesson 6Site selection for indoor unit: airflow, occupant comfort, food-product protection, mounting height and clearancesShows how to select the best indoor unit location for airflow, comfort, and product protection, considering mounting height, clearances, obstructions, and potential sources of contamination or drafts in Singapore homes and shops.
Avoiding drafts on occupants and bedsProtecting food and sensitive productsMounting height and ceiling distanceSide and bottom clearance needsAvoiding heat sources and sunlightLesson 7Mechanical mounting: indoor wall plate alignment, outdoor pad/bracket anchoring, anti-vibration considerationsCovers mounting of indoor and outdoor components, including wall plate alignment, condensate slope, pad or bracket anchoring, and anti-vibration measures to reduce noise and prevent structural damage in high-rise buildings.
Locating and levelling indoor wall plateAnchoring to studs or solid masonryOutdoor pad levelling and anchoringBracket mounting on walls or railsInstalling anti-vibration pads and feetLesson 8Electrical installation: circuit selection for 220V supply, disconnect and overcurrent protection sizing, grounding and control wiringFocuses on safe electrical installation for 220V units, including circuit selection, wire sizing, overcurrent protection, disconnect placement, grounding, and control wiring according to Singapore codes and manufacturer data.
Determining required circuit amperageSelecting wire gauge and insulationSizing breakers and fuses correctlyInstalling outdoor disconnect switchesGrounding and control wiring practicesLesson 9Pressure testing with dry nitrogen: test pressure selection, hold times, soap-test procedure for leak detectionExplains why dry nitrogen is used for pressure testing, how to choose safe test pressures, set realistic hold times, and apply soap solution correctly to locate leaks without damaging system components in humid conditions.
Selecting safe nitrogen test pressuresSetting and monitoring pressure hold timesSoap-solution application techniquesInterpreting pressure drops and trendsDocumenting and tagging leak locationsLesson 10Charging and opening service valves: correct refrigerant charge process, measuring superheat/subcooling, final leak checkExplains how to open service valves, verify factory charge, add or remove refrigerant when allowed, and confirm charge using superheat, subcooling, and a final leak check before handing over the system to clients.
Reviewing factory charge informationConnecting gauges and hoses safelyOpening liquid and gas service valvesMeasuring superheat and subcoolingPerforming final leak and soap tests
