ASHRAE: American Society of Heating, Refrigerating and Air-Conditioning Engineers
NMBE: Normalized Mean Bias Error
CVRMSE: Coefficient of Variation of the Root Mean Square Error
TMY3: Typical Meteorological Year 3
GHG: Greenhouse Gas
EUI: Energy Use Intensity
kBtu: Kilo British Thermal Unit
kWh: Kilowatt-hour
CFM: Cubic Feet per Minute
HVAC: Heating, Ventilation, and Air Conditioning
SIR: Savings to Investment Ratio
Definitions
Energy Assessment Report: A comprehensive evaluation of a building’s energy consumption patterns and potential areas for improvement.
Energy Conservation Measure (ECM): A specific action or upgrade designed to reduce energy consumption or improve energy efficiency in a building.
Climate Zone: A geographic region defined by ASHRAE standards, characterized by similar weather patterns, used to determine appropriate building energy codes and standards.
Whole Building Energy Modeling: A simulation technique that analyzes a building’s energy performance as a complete system, taking into account various factors such as climate, building envelope, and mechanical systems.
Energy Use Intensity (EUI): A measure of a building’s energy efficiency, calculated as the total energy consumed in a year divided by the total floor area of the building (typically expressed in kBtu/ft²).
ENERGY STAR Score: A 1-100 rating of a building’s energy efficiency compared to similar buildings nationwide, with higher scores indicating better performance.
Site EUI: The amount of energy consumed on-site in a building, typically measured in kBtu per square foot per year.
Asset Score: A rating of a building’s as-built physical characteristics and energy systems, independent of occupancy and operational factors.
In Operation Score: A rating that assesses how well a building’s systems are performing based on actual operational data.
Blended Rate: A single, average rate that combines various components of utility pricing, such as base rates, demand charges, and surcharges.
Payback Period: The time required for the savings from an energy efficiency measure to equal the initial investment cost.
Savings to Investment Ratio (SIR): A metric used to evaluate the cost-effectiveness of an energy efficiency project, calculated by dividing the present value of savings over the lifetime of the measure by the initial investment cost.
Weather Normalization: A technique used to adjust energy consumption data to account for variations in weather patterns, allowing for more accurate comparisons across different time periods or locations.
End-use Analysis: A breakdown of energy consumption by specific categories of use within a building, such as lighting, heating, cooling, or plug loads.
Setpoint Temperature: The desired temperature set for a building’s HVAC system to maintain during occupied periods.
Setback Temperature: A less stringent temperature setting used during unoccupied periods to reduce energy consumption while maintaining minimal comfort levels.
Normalized Mean Bias Error (NMBE): A statistical measure used to evaluate the accuracy of energy models. It represents the mean difference between measured and simulated data, normalized by the mean of the measured data. A lower NMBE indicates better model accuracy.
Coefficient of Variation of the Root Mean Square Error (CVRMSE): Another statistical measure used in energy modeling to assess the variability between measured and simulated data. It’s calculated as the root mean square error divided by the mean of the measured data. A lower CVRMSE indicates a better fit between the model and actual data.