Lesson 1Inverter (variable-speed) vs fixed-speed compressors: efficiency, part-load performance, inrush current, ambient considerationsCompare inverter and fixed-speed compressors for office use, looking at efficiency scores, part-load comfort, starting current, electrical sizing, and how they perform in hot and cool weather in the chosen Ghanaian climate.
How inverter drives adjust capacityFixed-speed behaviour at part loadInrush current and electrical sizingEfficiency ratings at full and part loadAmbient temperature effects on capacityLesson 2Choosing system type: single-split vs multi-split, benefits and tradeoffsFind out how to pick between single-split and multi-split systems for a 2,000 sq ft office, balancing zoning options, setup costs, upkeep trouble, backup plans, and room for growth in a typical Ghanaian business setting.
Zoning needs and temperature control goalsPiping layout and installation constraintsCost comparison: equipment and labourService access and maintenance complexityRedundancy and impact of unit failureLesson 3Estimating internal gains from computers and office equipment (W per workstation) and occupancy schedulesFigure out internal heat from computers, screens, printers, and people in a 2,000 sq ft office by guessing watts per workstation, diversity factors, and work schedules, then turn these into sensible and latent loads for accurate planning.
Typical W per workstation and equipmentDiversity factors for office equipment useOccupancy density and schedule profilesSeparating sensible and latent componentsConverting internal gains to BTU/h loadsLesson 4Preparing a short justification statement referencing a chosen city climate (sensible/latent balance) and recommended unit specification sheet items (capacity, SEER/IEER, sound, dimensions)Practice writing a short reason for the picked system using a specific city climate like Kumasi, noting sensible and latent balance, and main spec sheet details such as capacity, SEER or IEER, noise levels, and unit sizes.
Choosing a representative city climateSummarizing sensible and latent loadsReferencing capacity and efficiency ratingsIncluding sound, size, and clearance dataStructuring a clear justification paragraphLesson 5Calculating sensible and latent heat loads: people, equipment, lighting, envelopeBuild skills to work out sensible and latent loads from people, equipment, lights, and the building shell, then add them up into a total design load that matches real working conditions for the 2,000 sq ft office in Ghana.
People loads: sensible and latent splitsEquipment and lighting heat gain methodsEnvelope loads: walls, roof, and glassUsing CLF or similar factors for timingCombining components into design loadLesson 6Selecting capacity in BTU/h and tons: rounding, safety factors, diversity and part-load considerationsLearn to choose system capacity in BTU/h and tons for the office, covering rounding rules, safety margins, zone diversity, and part-load running so equipment works well without constant short stops.
Converting calculated load to nominal tonsRounding up or down from load resultsApplying reasonable safety factorsAccounting for diversity across office zonesChecking part-load operation and cyclingLesson 7Refrigerant options and implications for performance and serviceability (R410A, R32, others)Look at common coolants like R410A and R32, comparing efficiency, pressure, glide, fire risk, and environment effects, and see how choice impacts piping, tools, and future rules in Ghana.
Key properties of R410A and R32Efficiency and capacity differences by refrigerantSafety, flammability, and code requirementsImpact on piping, charge, and componentsService tools, training, and phaseout risksLesson 8Using simplified load sizing rules (BTU/ft²) and comparison with manual J style estimatesLearn to use simple BTU per square foot rules for quick office load guesses, then compare and adjust them against Manual J methods to know limits, fixes, and when full calculations are needed in local settings.
Typical BTU/ft² ranges for office spacesAdjusting rules for climate and building qualityComparing quick rules to Manual J style resultsRecognizing when rules of thumb failApplying safety factors without oversizingLesson 9Selecting auxiliary features: filtration level, noise ratings (dB), controls and connectivity optionsLearn to pick filter levels, noise ratings, and control choices that fit office comfort, air quality, and IT needs, including MERV filter picks, dB goals, smart controls, and links to building systems.
Choosing MERV rating and filter typeNoise criteria and target indoor dB levelsFan speed settings and sound tradeoffsThermostat types and scheduling optionsConnectivity, BACnet, and app integrationLesson 10Matching indoor unit airflow and coil selection to room sensible load and thermostat placementUnderstand matching indoor unit airflow and coil size to room sensible loads, thinking about thermostat spot, air throw, diffuser choice, and avoiding drafts or uneven air that cause comfort issues in office areas.
Calculating required CFM from sensible loadSelecting coils for sensible heat ratioAir throw, diffuser type, and coverageThermostat location and sensor placementAvoiding drafts, short cycling, and stratification
