NATE Senior Efficiency Analyst study plan

Map the pressure–airflow relationship across a fan curve and label the operating point on a hand-sketched system resistance curve

Compute total external static pressure from a set of supply and return readings and state the acceptable range for a residential air handler

Convert between cfm, velocity, and duct cross-sectional area for rectangular and round ducts without a calculator app

Identify the five most common duct defects (leakage, undersized return, excessive flex, sharp elbows, crushed runs) and rank them by capacity loss

Calculate duct leakage as a percentage of system airflow using a calibrated fan test result and explain the threshold that triggers remediation

Size a return duct and a supply trunk for a stated cfm and friction rate using a duct calculator or friction chart

Diagnose a high-static system from a written scenario and prescribe three corrective measures in priority order

Explain how filter pressure drop and coil fouling shift the fan operating point

Compute EER, SEER2, and HSPF2 from delivered capacity and input power for a worked example and explain what changed between SEER and SEER2

Distinguish rated conditions from field conditions and state why field-measured efficiency diverges from the rating

Calculate sensible heat ratio and explain its effect on latent capacity and occupant comfort

Identify the efficiency penalty of oversizing and short cycling using a part-load curve

Trace the vapor-compression cycle on a pressure–enthalpy diagram and label all four state points from gauge readings and line temperatures

Compute superheat and subcooling from a set of readings and state target ranges for a TXV and a fixed-orifice system

Calculate refrigeration effect and mass flow from enthalpy values

Explain how condenser approach temperature and evaporator approach reveal coil or airflow problems

Diagnose undercharge, overcharge, restricted metering device, and non-condensable contamination from superheat, subcooling, and approach patterns

Explain how airflow error corrupts superheat and subcooling readings and state the sequence that isolates airflow before charge

Describe the recovery, evacuation, and weighing procedure for a charge adjustment and the documentation each step requires

Identify refrigerant-specific glide and fractionation concerns for a zeotropic blend and the correct charging method

Build a measurement plan that specifies instrument type, accuracy, and calibration interval for temperature, pressure, airflow, and power

Compute annual energy use and cost from measured kW, runtime hours, and a tariff schedule including demand charges

Apply the correct formula for duct leakage, airflow, and capacity uncertainty propagation and state the confidence band on a savings estimate

Sequence a field verification so that airflow is established before capacity and efficiency are measured

Convert measured data into a normalized savings figure using a baseline model and explain the normalization assumptions

Draft a customer-facing report that states findings, measured evidence, recommended measures, cost, and expected savings in plain language

Anticipate three customer objections to a recommended measure and write a factual response to each

Check a report for documentation gaps that would fail a third-party review, including missing baseline, missing calibration records, and unsupported savings claims

Complete a timed full-length practice set across all four domains and score each domain separately

Re-derive the ten formulas you missed most often and write them from memory

Re-teach the two weakest domain concepts aloud in under five minutes each without notes

Review every flagged item and record the specific knowledge gap and the source you will use to close it