Glossary of Key Terms
The terms below are provided to help readers better understand the language used throughout the SSAFE Pathway to Net Zero. Some words and abbreviations are common in the fields of energy, sustainability, and climate action but may be unfamiliar to those new to these topics. We encourage readers to refer to this glossary whenever a term or concept needs clarification.
A
ASHRAE Audit Levels – A standard set of building energy audit types defined by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers.
- Level 1 (Walk-through Audit): Visual inspection and utility bill review to identify simple, low-cost improvements.
- Level 2 (General Audit): More detailed measurements, data collection, and cost/savings analysis.
- Level 3 (Investment-Grade Audit): Comprehensive engineering analysis, sub-metering, and lifecycle cost evaluation, often for major capital projects. See also Department of Energy GHG Emissions Reduction Audit and the SSAFE Energy/GHG Audit Request for Proposal Template.
Audit (Energy/GHG Audit) – A systematic study of how a building uses energy, identifying where improvements can save energy and reduce greenhouse gas emissions.
Autonomous Mowers – Robotic, battery-powered mowers that reduce fuel use and labor demands for groundskeeping.
B
Bathtub Analogy (Climate) – A simple way to visualize greenhouse gas buildup in the atmosphere: the faucet represents emissions going in, the drain represents the Earth’s limited absorption capacity, and the tub represents the atmosphere.
Baseline Emissions Inventory – The starting measurement of a community’s annual greenhouse gas emissions, against which future reductions are tracked.
Btu (British Thermal Unit) – A unit of energy. One Btu is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
C
Carbon Offset – A purchased credit representing a reduction of emissions elsewhere, used to compensate for emissions that are difficult to eliminate directly.
Carbon Sequestration – The long-term capture and storage of carbon dioxide, often through natural systems like forests or technological systems like carbon capture facilities.
Carbon Neutrality – A condition where the net emissions of greenhouse gases are zero, achieved through a combination of reductions and offsets.
Clean Energy – Energy derived from sources that generate power without releasing greenhouse gases: solar power (photovoltaic, solar thermal), wind power, hydropower, geothermal energy, and hydrogen if it is produced by any of the proceeding technologies.
CO₂e (Carbon Dioxide Equivalent) – A metric that expresses the impact of all greenhouse gases in terms of the equivalent amount of CO₂ that would produce the same warming effect.
Commissioning / System Tune-ups – The process of testing, adjusting, and calibrating building systems (such as heating and cooling) to ensure they perform as intended.
Cross-Campus Sustainability Tracker – A tool developed by SSAFE to track and compare sustainability initiatives across multiple senior living communities.
D
Demand Response – Programs that compensate facilities for reducing electricity use or running on-site generation during peak grid demand periods.
Distributed Generation – Electricity produced at or near the point of use (e.g., rooftop solar panels), rather than at large, centralized power plants.
DSIRE – Database of State Incentives for Renewables & Efficiency, a U.S. resource that lists available grants, rebates, and incentives.
E
EEM (Energy Efficiency Measure) – A specific project or action designed to reduce energy use without reducing service or comfort (e.g., LED lighting upgrades).
Embodied Carbon – Greenhouse gas emissions associated with the production, transport, and installation of building materials (e.g., concrete, steel, insulation).
Energy Conversion Calculators – Online tools (such as those provided by the U.S. Energy Information Administration) that convert energy units into consistent measures.
ERM (Emissions Reduction Measures) – While many efficiency measures also reduce emissions, some actions are specifically aimed at cutting greenhouse gas output. These can include replacing a gas boiler with an electric heat pump, switching to renewable electricity, or phasing out diesel-powered vehicles. Such measures go beyond saving energy, they directly reduce the community’s carbon footprint.
ERM (Energy Reduction Measure) – Broader than efficiency measures, can include both using less energy for the same service and reducing the service itself.
EUI (Energy Use Intensity) – A measure of energy performance, expressed as energy consumed per square foot per year. Lower numbers indicate higher efficiency. EUI is closely linked to greenhouse gas emissions, since more energy use typically means more emissions if the energy is derived from fossil fuels. See also Greenhouse Gas Emission Intensity (GHG-EI) for a related measure focused on emissions.
F
Fuel Cells – Devices that generate electricity through a chemical process (often using natural gas or hydrogen) with higher efficiency and fewer emissions than traditional combustion.
G
GHG (Greenhouse Gas) – Gases that trap heat in the atmosphere, including carbon dioxide, methane, nitrous oxide, and fluorinated gases.
GHG-EI (Greenhouse Gas Emission Intensity) – The amount of greenhouse gas emissions produced per unit of activity, such as per square foot of building space or per resident. It allows communities to compare emissions across different buildings or time periods, regardless of size or occupancy. See also Energy Use Intensity (EUI) for a related measure focused on energy consumption.
Global Warming Potential (GWP) – A measure of how much heat a greenhouse gas traps in the atmosphere compared to CO₂ over a given period (typically 100 years).
H
Halogenated Refrigerants – Powerful greenhouse gases used in cooling systems (e.g., freon). Their leakage contributes significantly to warming if not properly managed.
Heat Recovery Ventilator (HRV) – A mechanical system that exchanges stale indoor air with fresh outdoor air while recovering heat, improving efficiency in tight buildings.
Heat Pump – An electric device that moves heat rather than creating it, used for space heating, cooling, and hot water.
Hybrid Vehicles – Vehicles that combine an internal combustion engine with a battery and electric motor, providing partial emissions reductions compared with conventional vehicles.
I
Induction Cooking – A highly efficient cooking method that uses magnetic fields to directly heat pots and pans, reducing wasted heat and improving indoor air quality.
Investment-Grade Audit – See ASHRAE Audit Level 3 as well as the Department of Energy GHG Emissions Reduction Audit and the SSAFE Energy/GHG Audit Request for Proposal Template.
L
Life Cycle Cost Analysis – A method of comparing the long-term costs of equipment or projects, including purchase price, operating costs, maintenance, and eventual replacement.
Load Shifting – Moving energy use (such as pool pumps or laundry) to off-peak hours to reduce emissions and costs.
M
MMBtu (Million British Thermal Units) – A standard unit of energy used in large-scale calculations.
Microgrid – A localized energy grid that can disconnect from the main grid and operate independently, often incorporating solar and batteries.
N
Net Zero – A condition in which the amount of greenhouse gas emissions released is fully balanced by actions that remove or offset emissions.
Nitrous Oxide (N₂O) – A potent greenhouse gas with a global warming potential 265 times that of CO₂, often produced by fertilizers and fossil fuel combustion.
P
PPA (Power Purchase Agreement) – A long-term contract to purchase renewable electricity at a fixed price, often used for solar or wind projects.
Peak Shaving – Reducing energy use during times of highest demand on the electrical grid, lowering costs and easing grid strain.
Photovoltaics (PV) – Technology that converts sunlight directly into electricity, commonly used in solar panels.
Portfolio Manager – A free online tool from the U.S. EPA for tracking building energy use and emissions, often used as an entry-level benchmarking system.
R
REC (Renewable Energy Certificate) – A tradable credit that verifies one megawatt-hour of electricity was generated from renewable sources. Needed to credibly claim renewable energy use.
Retrofit – Upgrading an existing building or system with new technologies to improve efficiency and reduce emissions.
S
Scope 1 Emissions – Direct emissions from sources owned or controlled by the community (e.g., boilers, campus vehicles).
Scope 2 Emissions – Indirect emissions from purchased electricity.
Scope 3 Emissions – Indirect emissions from upstream and downstream activities (e.g., food supply, commuting, waste).
SIMAP (Sustainability Indicator Management & Analysis Platform) – A subscription tool developed by the University of New Hampshire for comprehensive carbon and nitrogen accounting.
Solar Canopy – Solar panels installed over parking lots or walkways, generating power while providing shade and weather protection.
Sub-Metering – Adding meters to track energy use in specific buildings or systems, improving accuracy of savings verification.
System Tune-Up (Commissioning) – See Commissioning.
W
Weather Normalization – A statistical adjustment to account for unusual heating or cooling demands caused by weather, so energy data can be compared fairly year to year.
