Energy audit glossary
Clear definitions of the terms and acronyms used in energy audits, ASHRAE standards, and building performance analysis.
Energy Use Intensity (EUI)
Annual energy use divided by building floor area, typically expressed in kWh/m²/year or kBtu/ft²/year.
Baseline
The energy use against which post-retrofit savings are compared, usually weather-normalized.
Weather Normalization
Adjusting energy use data to remove the effects of weather variation year over year.
Degree Days
A measure of how much outdoor air temperature deviates from a base temperature over time.
Measurement and Verification (M&V)
The process of quantifying actual energy savings after an energy conservation measure is implemented.
IPMVP
International Performance Measurement and Verification Protocol — the standard framework for M&V.
Calibrated Energy Model
A simulation model tuned to match actual utility consumption within accepted statistical tolerances.
ASHRAE Guideline 14
ASHRAE guideline defining measurement of energy and demand savings, including calibration metrics.
NMBE
Normalized Mean Bias Error — a measure of overall model bias compared to measured data.
CV-RMSE
Coefficient of Variation of the Root Mean Square Error — a measure of model error relative to average consumption.
Energy Conservation Measure (ECM)
A specific action or project that reduces building energy use or demand.
Simple Payback
The time required for energy savings to equal the initial project cost.