AEE Business Energy Professional cheat sheet

ASHRAE 90.1 establishes minimum energy-efficiency requirements for most commercial and high-rise residential buildings; compliance paths include prescriptive, trade-off, and energy cost budget.

ASHRAE 62.1 addresses ventilation and indoor air quality in commercial buildings; ASHRAE 62.2 covers residential ventilation.

IECC contains commercial and residential energy provisions; ASHRAE 189.1 and IgCC are green-building codes.

NFPA 70 is the National Electrical Code; NFPA 70E addresses electrical safety in the workplace.

ISO 50001 specifies an energy management system; ISO 50006 covers energy performance indicators and baselines; ISO 50015 covers M&V.

ASHRAE Guideline 0 describes the commissioning process; ASHRAE Guideline 14 covers measurement of energy and demand savings.

EPA 40 CFR Part 75 requires continuous emission monitoring for affected electric utility units; Part 60 New Source Performance Standards apply to new or modified sources.

FERC Uniform System of Accounts prescribes accounting for regulated utilities; state public utility commissions set retail rate structures.

LEED rating systems group credits into categories such as integrative process, location and transportation, sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, innovation, and regional priority.

EUI = annual site energy use / conditioned floor area; lower EUI generally indicates lower operational energy intensity, but fuel mix and climate affect comparisons.

Source energy converts site energy by upstream factors and is used to compare total primary energy; site energy counts only energy delivered to the building.

A net-zero energy building produces on-site renewable energy equal to or greater than annual site energy consumption over the defined boundary.

Green roofs reduce roof heat gain, mitigate urban heat island, and retain stormwater; they add structural load and require maintenance.

Daylighting can reduce lighting energy, but glare control and solar gain management are required to avoid cooling penalties.

Commissioning is a LEED prerequisite in the Energy and Atmosphere category; enhanced commissioning is an optional credit.

Embodied carbon is emissions from materials and construction; operational carbon is emissions from building energy use.

1 kWh = 3,412 Btu; 1 therm = 100,000 Btu; 1 ton of refrigeration = 12,000 Btu/h.

Sensible heat Q = m cp ΔT; latent heat Q = m hfg; total coil load combines both.

Power factor PF = kW / kVA; kW = kVA × PF for sinusoidal loads.

Three-phase real power kW = √3 × VLL × I × PF / 1000.

Fan and pump affinity laws: flow ∝ speed, head ∝ speed², and shaft power ∝ speed³ at constant efficiency.

Conduction heat Q = U × A × ΔT; R-value = 1/U.

COP = useful cooling or heating output / energy input; EER = Btu/h output per watt input; EER ≈ COP × 3.412.

Combustion excess air raises stack losses; stoichiometric air is the minimum air for complete combustion.

Load factor = average load / peak load over a period; high load factor spreads fixed costs over more energy.

Energy charge bills $/kWh; demand charge bills $/kW or $/kVA based on the billing peak.

A ratchet clause sets billed demand from a prior peak when current demand is lower.

Time-of-use rates assign higher prices to on-peak periods and lower prices to off-peak periods.

Block or tiered rates change the $/kWh as consumption crosses defined blocks.

Power-factor penalties apply when PF falls below a threshold; kVA billing charges apparent power.

Real-time pricing varies with wholesale market prices; critical-peak pricing adds high-price event periods.

Standby and backup charges recover utility capacity for customers with on-site generation.

Minimum bills, riders, taxes, and late fees can make the effective rate differ from the stated commodity rate.

Fixed-price supply locks the commodity price for a term; indexed supply varies with a published index plus a basis or adder.

Wholesale electric markets use locational marginal pricing; retail supply adds transmission, distribution, and regulatory components.

Hedging uses futures, swaps, or physical contracts to reduce price volatility; basis risk remains between index and delivery point.

Natural gas heat rate = Btu of fuel per kWh generated; lower heat rate means higher conversion efficiency.

Firm pipeline transportation guarantees capacity; interruptible service is lower cost but can be curtailed.

Gas storage and balancing services manage seasonal and daily demand swings; imbalance penalties apply outside tolerances.

Spark spread = electricity price − (gas price × heat rate); positive spread favors gas-fired generation.

Creditworthiness, contract term, volume tolerance, and change-of-law provisions are material procurement terms.

Energy balance: purchased energy = useful output + conversion losses + distribution losses + unaccounted energy.

EUI = annual energy use / floor area; weather-normalized EUI adjusts for heating and cooling degree days.

Baseline energy is normalized for independent variables such as weather, occupancy, production, and operating hours.

Utility bill audit checks meter multipliers, rate schedule, demand ratchets, power factor, taxes, and riders.

Accrual accounting records energy cost in the period consumed; invoice accounting records it when billed.

Submetering allocates cost by tenant or cost center and supports efficiency accountability.

Cost per unit of production = energy cost / output; it is useful when product mix is stable.

Energy intensity can be expressed in Btu/ft², kWh/ft², kWh/unit, or cost/unit depending on the decision.

Scope 1 covers direct emissions from owned or controlled sources; Scope 2 covers purchased electricity, steam, heat, or cooling; Scope 3 covers value-chain emissions.

Scope 2 location-based method uses grid-average emission factors; market-based method uses contractual instruments such as RECs.

Emissions = activity data × emission factor; convert to CO2e with global warming potentials.

GHG Protocol corporate standard defines boundary and reporting principles; the Scope 2 guidance defines dual reporting.

Organizational boundaries include equity share, financial control, or operational control.

Renewable energy certificates can lower market-based Scope 2 emissions when eligibility and delivery requirements are met.

Carbon offsets reduce net emissions outside the value chain; avoided emissions are not counted as reductions under GHG Protocol.

Common units: 1 metric ton = 1,000 kg = 2,204.6 lb; CO2e normalizes different gases to carbon dioxide.

Interval meters record demand over fixed periods, commonly 15 minutes; AMI enables remote reading and interval data.

Current transformers and potential transformers scale meter readings; the multiplier equals CT ratio × PT ratio.

Meter accuracy class defines allowable error; check meters and portable loggers verify billing meters.

EIS platforms perform bill verification, load profiling, benchmarking, alarms, and savings tracking.

BACnet and Modbus are common building and meter communication protocols; pulse inputs count kWh or gas volume.

Missing interval data must be flagged and estimated with a documented method before baseline or savings calculations.

Weather normalization uses degree days or regression to separate weather effects from efficiency changes.

Data quality checks include time synchronization, gap detection, range checks, and unit consistency.

ASHRAE Level 1 is a preliminary walk-through; Level 2 is an energy survey and analysis; Level 3 is an investment-grade analysis.

A power logger records kW, kWh, PF, and demand over time; a clamp meter gives instantaneous current.

Infrared thermography identifies insulation defects, air leakage, moisture, and electrical hot spots.

Combustion analyzers measure O2, CO, CO2, and stack temperature to estimate excess air and efficiency.

Balometers measure hood airflow at grilles; anemometers measure duct or outdoor air velocity.

Blower-door testing measures envelope airtightness; duct blasters measure duct leakage.

Sampling plans must be representative of equipment, occupancy, and operating schedules.

Measurement uncertainty should be stated; savings smaller than uncertainty are not reliably demonstrated.

Simple payback = initial cost / annual savings; it ignores savings after payback and time value of money.

NPV = sum of discounted cash flows minus initial cost; accept projects with positive NPV at the hurdle rate.

IRR is the discount rate that makes NPV zero; compare IRR with the organization’s hurdle rate.

Levelized cost of energy = present value of life-cycle costs / present value of energy output.

Energy savings performance contracts use guaranteed savings to fund upgrades; measurement and verification defines the guarantee.

Power purchase agreements buy output from a third-party owned system; the host avoids capital cost.

Capital leases, operating leases, and on-bill financing shift cost recovery over time.

Incentives, rebates, tax credits, and accelerated depreciation reduce net capital cost but may have eligibility limits.

Commissioning phases include pre-design, design, construction, acceptance, and post-acceptance; OPR and BOD guide design and testing.

Functional performance testing verifies systems under normal, part-load, and failure modes; issues are tracked to closure.

Retrocommissioning applies commissioning to existing buildings without major capital upgrades.

IPMVP Option A measures retrofit isolation with stipulated operational factors; Option B measures retrofit isolation with continuous measurements.

IPMVP Option C uses whole-facility metering; Option D uses calibrated simulation.

Savings = adjusted baseline energy − reporting-period energy; adjustments account for weather, occupancy, and production changes.

Measurement boundary defines which meters, fuels, and loads are included in the savings calculation.

ASHRAE Guideline 14 provides methods for measuring energy and demand savings; uncertainty should be reported.

Continuous commissioning uses trend data and alarms to maintain performance after initial commissioning.

Chiller efficiency is expressed as kW/ton or COP; 1 kW/ton equals a COP of about 3.517.

Boiler thermal efficiency = useful heat output / fuel energy input; stack loss and blowdown are major losses.

Economizers use cool outdoor air to reduce mechanical cooling when outdoor enthalpy or temperature is favorable.

VAV systems vary supply air volume; minimum airflow settings protect ventilation and coil stability.

Lighting power density LPD = connected lighting watts / floor area; controls reduce hours of operation.

Variable frequency drives reduce motor power approximately with the cube of speed for centrifugal loads.

Envelope performance depends on insulation, air sealing, glazing U-factor, solar heat gain coefficient, and thermal bridging.

Domestic hot water energy depends on volume, temperature rise, standby loss, and distribution losses.

Compressed air specific power is kW per 100 cfm; leaks, artificial demand, and pressure drop raise specific power.

Steam traps remove condensate and non-condensable gases; failed-open traps waste steam and failed-closed traps cause water hammer.

Condensate return and flash steam recovery reduce boiler fuel and makeup water treatment.

Boiler blowdown controls dissolved solids; excessive blowdown wastes energy and water.

Waste heat recovery can preheat combustion air, feedwater, or process streams.

Pump and fan systems should be optimized by trimming impellers, reducing speed, or reducing system resistance before adding controls.

Cooling tower approach = leaving water temperature − wet-bulb temperature; lower approach improves chiller efficiency but needs more tower capacity.

Motor efficiency and load factor determine replacement economics; oversizing reduces part-load efficiency.

CHP total efficiency = (useful electric output + useful thermal output) / fuel energy input.

Topping-cycle CHP generates power first and uses exhaust heat; bottoming-cycle CHP uses process heat first and generates power from waste heat.

Prime movers include reciprocating engines, gas turbines, microturbines, fuel cells, and steam turbines.

Heat-to-power ratio of the load should match the prime mover; mismatch reduces utilization or requires supplemental heat.

Spark spread = electric price − fuel price × heat rate; positive spread supports dispatch.

Absorption chillers convert waste heat or steam into cooling and can improve summer thermal utilization.

Interconnection rules, standby charges, net metering, and export limits affect CHP economics.

Emissions permitting and air-quality limits apply to on-site generators; islanding requires protective relaying and utility approval.