Eco-Dictionary
The Eco-Dictionary was created to help you navigate through the often-confusing world of eco-terminology. We update the dictionary regularly; to suggest an addition and/or change to the Eco-Dictionary, please contact us or visit our Forum.
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ACH: air changes per hour; a measurement for air infiltration.
Albedo: synonymous with solar reflectance.
Annual Fuel Utilization Efficiency (AFUE): measures the amount of fuel converted to heat in proportion to the amount of fuel entering the furnace (higher the better).
Automatic Duplexing: the capability of a copier, fax machine, multi-functional device, or printer to automatically place images on both sides of an output sheet, without manual manipulation of output as an intermediate step (examples of this are one-sided to two-sided copying and two-sided to two-sided copying).
Biodegradable: capable of being broken down into innocuous products by the action of living things.
Biodiversity: the variety of life in all forms, levels and combinations, including ecosystem diversity, species diversity, and genetic diversity.
British Thermal Unit (Btu): a unit of energy used in the power, steam generation, heating and air conditioning industries.
Brominated Flame Retardants (BFRs): refers a wide range of brominated chemicals commonly added to electronic products to reduce flammability, many of which have known toxic properties, are highly resistant to degradation in the environment and are able to bioaccumulate (build up in animals and humans).
Building Envelope: the exterior surface of a building’s construction – the walls, windows, roof and floor.
Cadmium: a soft, malleable, ductile, toxic, bluish-white bivalent metal, the poisoning of which is an occupational hazard associated with industrial processes such as metal plating and the production of nickel-cadmium batteries, pigments, plastics, and other synthetics (inhalation of cadmium-containing fumes can result initially in metal fume fever but may progress to chemical pneumonitis, pulmonary edema, and death).
Chain-of-Custody: a document that tracks a wood product from the forest to a vendor (typically used to verify compliance with FSC guidelines).
Chlorofluorocarbons (CFCs): hydrocarbons that deplete the stratospheric ozone layer.
CO2: carbon dioxide.
Coefficient of Performance (COP): the ratio of the change in heat at the "output" (the heat reservoir of interest) to the supplied work (applicable to heat pumps). Example: a geothermal heat pump operating at COP heating 3.5 provides 3.5 units of heat for each unit of energy consumed (e.g. 1 kwh consumed would provide 3.5 kwh of output heat) - the output heat comes from both the heat source and 1 kwh of input energy, so the heat-source is cooled by 2.5 kwh, not 3.5 kwh.
Composite Wood: a product consisting of wood or plant particles or fibers bonded together by a synthetic resin or binder (e.g. plywood, particle-board, MDF).
Condensation Resistance (CR): measures the ability of a product to resist the formation of condensation on the interior surface of that product; expressed as a number between 0 and 100 (the higher the CR rating, the better that product is at resisting condensation formation).
Conditioned Space: the space of a building that is controllably heated or cooled, or both, for the comfort of occupants.
Conversion Efficiency: the proportion of sunlight energy that a photovoltaic cell converts to electrical energy (applied to solar panels).
Daylighting: the controlled admission of natural light into a space through glazing with the intent of reducing or eliminating electric lighting.
Dow Jones Sustainability Index: launched in 1999 as the world’s first equity benchmark to track the financial performance of sustainable leaders on a global scale; based on long-term economic, environmental and social performance among top 10% of the world’s 2,500 largest companies - includes the assessment of issues such as corporate governance, risk management, branding, supply chain standards and labor practices (the Index is regularly verified by auditor Pricewaterhouse Cooper).
Drip Irrigation: a high-efficiency irrigation method in which water is delivered at low pressure through buried mains and sub-mains (from the sub-mains, water is distributed to the soil from a network of perforated tubes or emitters).
Eco-innovation: a term used to describe products and processes that contribute to sustainable development.
Ecosystem: a basic unit of nature that includes a community of organisms and their non-living environment linked by biological, chemical and physical process.
Electronic Product Environmental Assessment Tool (EPEAT): a system to help purchasers in the public and private sectors evaluate, compare and select desktop computers, notebooks and monitors based on their environmental attributes.
Emissivity: the ratio of the radiation emitted by a surface (e.g. grass) to the radiation emitted by a blackbody (e.g. asphalt) at the same temperature.
Energy Efficiency: using less energy to provide the same level of energy service.
Energy Efficiency Ratio (EER): the steady-state rate of heat energy removal (i.e. cooling capacity) by a product measured in Btuh divided by the steady-state rate of energy input to the product measured in watts - the higher the EER, the more efficient the cooling unit.
Energy Factor: the ratio of useful energy output from a product to the total amount of energy delivered to the product (the higher the EF is, the more efficient the product - typically applied to water heaters).
ENERGY STAR®: a joint program of the EPA and the U.S. Department of Energy; also a label which serves as the trusted national symbol for environmental protection through superior energy efficiency. Click here to visit ENERGY STAR's website.
Environmentally Preferable Products: products identified as having a lesser or reduced effect on health and the environment when compared with competing products that serve the same purpose.
Environmentally Preferred Purchasing (EPP): typically in the form of a policy, encourages and assists government agencies the purchasing of Environmentally Preferable Products.
Environmental Protection Agency (EPA): United States government agency that leads the nation's environmental science, research, education and assessment efforts with a mission to protect human health and the environment.
Environmental Stewardship: the concept that we are entrusted with the care and protection of our planet.
EPA Smartway: The U.S. Environmental Protection Agency's rating for vehicles that have low air pollution impacts and low greenhouse gas emissions; these vehicles are considered by the EPA to be very good environmental performers relative to other vehicles.
European Council Directive 67/548/EEC (The Dangerous Substances Directive as amended): applies to pure chemicals and to mixtures of chemicals (preparations) that are placed on the market in the European Union.
EU Eco-Management and Audit Scheme (EMAS): a management tool for companies and other organisations to evaluate, report and improve their environmental performance.
European Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations (RoHS regulations): the regulations that implement EU Directive 2002/95 which bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants.
First-Hour Rating (FHR): the amount of hot water in gallons a storage water heater can supply per hour (starting with a tank full of hot water).
Fly Ash: the solid residue derived from incineration processes (can be used as a substitute for cement in concrete).
Footcandle (fc): a unit of illuminance equal to one lumen of light falling on one-square foot area from one candela light source at a distance of one foot.
Forest Stewardship Council (FSC): an independent, non-governmental, not for profit organization established to promote the responsible management of the world’s forests.
Formaldehyde: a naturally occurring volatile organic compound found in small amounts in animals and plants that is carcinogenic and an irritant to humans when present in high concentrations.
Gallons per Cycle (GPC): used to measure the water efficiency of dishwashers.
Gallons per Flush (GPF): the amount of water used to flush a toilet once.
Gallons per Minute (GPM): the amount of hot water in gallons a tankless water heater can supply per minute over a 77°F temperature rise.
Glazing Factor: the ratio of interior illuminance at a given point on a given plane to the exterior illuminance under overcast sky conditions.
Global Reporting Initiative (GRI): a multi-stakeholder network of thousands of experts, in dozens of countries worldwide, organized with a mission to create conditions for the transparent and reliable exchange of sustainability information through the development and continuous improvement of a sustainability reporting framework.
Graywater/Greywater/Gray water: untreated household wastewater that has not come into contact with toilet waste - includes used water from bathtubs, showers, bathroom wash basins, and water from clothes washers (does not include wastewater from kitchen sinks or dishwashers); can be used in some areas, depending on local code regulations, to irrigate landscaping or flush toilets and help reduce potable water use.
Green: a term used to distinguish a product, practice, policy or ideology that promotes environmental protection, natural resource conservation, human health, regionalism, and social responsibility.
GREENGUARD Environmental Institute (GEI): an industry-independent, non-profit organization with a mission to improve public health and quality of life through programs that improve indoor air.
Greenhouse Gases: gases such as carbon dioxide, methane and CFCs that are relatively transparent to the higher-energy sunlight, but trap lower-energy infrared radiation and are the fundamental cause of the greenhouse effect.
Green Seal: an independent non-profit organization dedicated to safeguarding the environment and transforming the marketplace by promoting the manufacture, purchase and use of environmentally responsible products and services (visit http://www.greenseal.org to learn more).
Heat Island Effect: occurs when warmer temperatures are experienced in urban landscapes compared to adjacent rural areas as a result of solar energy retention on constructed surfaces. Dark colored surfaces like asphalt have a greater impact on heat island effect because they absorb – instead of reflect – solar energy.
Heating Seasonal Performance Factor (HSPF): refers to a heat pump's estimated seasonal heating output in BTUs divided by the amount of energy that it consumes in watt-hours; the higher the HSPF, the more energy-efficient the unit.
Hexavalent Chromium: refers to chemical compounds that contain the element chromium in the +6 oxidation state; recognized as a human carcinogen via inhalation.
Heterojunction with Intrinsic Thin (HIT) layer: applies to Sanyo photovoltaic cell technology (as temperatures rise, HIT Power solar panels produce 10% or more electricity than conventional crystalline silicon solar panels at the same temperature).
HVAC: heating, ventilation, air conditioning.
Hybrid (Vehicles): a vehicle with more than one power source such as a small internal combustion engine and an electric motor.
Hydrochlorofluorocarbons (HCFCs): refrigerants used in building equipment that deplete the stratospheric ozone layer.
Hydrofluorocarbons (HFCs): refrigerants that do not deplete the stratospheric ozone layer; some HFCs have high global warming potential and therefore are not environmentally benign.
Impervious: refers to a surface that promotes stormwater runoff instead of infiltration into the ground (e.g. asphalt).
Infrared (Thermal) Emittance: a parameter between 0 and 1 that indicates the ability of a material to shed infrared radiation (heat).
ISO: International Standards Organization
ISO 14000: addresses "Environmental management," or what an organization does to minimize harmful effects on the environment caused by its activities and to achieve continual improvement of its environmental performance.
ISO 14001: a management tool enabling an organization of any size or type to identify and control the environmental impact of its activities, products or services; to improve its environmental performance continually; and to implement a systematic approach to setting environmental objectives and targets, to achieving these and to demonstrating that they have been achieved.
Janka test: measures the hardness of wood by evaluating the force required to embed a 11.28 millimeter (0.444 inch) steel ball into wood to half its diameter; one of the best measures of the ability of a wood species to withstand denting and wear; also a good indicator of how hard a species is to saw or nail.
Kelvin: a unit increment of temperature based on a thermodynamic (absolute) temperature scale where absolute zero, the theoretical absence of all thermal energy, is zero (often used to measure the color temperature of light sources).
Kilowatt (kW): a unit of energy equal to one thousand watts.
Kilowatt Hours (kWh): the product of power in kilowatts multiplied by time in hours; not kilowatts per hour.
Lead: a poisonous metal that can damage nervous connections (especially in young children) and cause blood and brain disorders.
Leadership in Energy and Environmental Design® (LEED): a green building rating system created and administered by the USGBC to promote a whole-building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, material selection and indoor air quality.
LEED Accredited Professional (AP): accreditation that recognizes building professionals who have the knowledge and skills to successfully steward the integrated design and LEED certification process.
Lifecycle Cost: cost of ownership, including purchase price and cost of operation.
Light Output in Lumens: measures the efficiency of a light bulb - the higher number of lumens per watt a light bulb can produce, the more efficient it is (compact fluorescent lights - CFLs - for example, are more efficient than incandescent lights because they use less electricity - or wattage - to produce the same amount of light.
Low-emissivity (Low-E): special coatings that reflect infrared light, keeping heat inside in winter and outside in the summer (typically applied to windows).
Low or No Toxicity: Products containing no or low toxicity, reducing the quantity of air contaminants that are odorous, irritating and/or harmful to humans and the natural environment (examples of harmful toxins often found in building materials include Volatile Organic Compounds [VOCs, found in paint] and urea-formaldehyde [found in plywood]).
Low Solar Reflectance: Products that absorb rather than reflect solar energy, creating “cool” pavement and reducing heat island effect.
MBTUH: one thousand British Thermal Units (BTUs) per hour.
Mercury: a chemical element with compounds that are extremely toxic.
Minimum Efficiency Reporting Value (MERV): a number from 1 to 16 that is relative to an air filter’s efficiency; the higher the MERV, the more efficient the air filter is at removing particles.
National Fenestration Rating Council (NFRC): a non-profit organization that administers a uniform, independent rating and labeling system for the energy performance of windows, doors, skylights, and attachment products.
Non-potable Water: Water that is not suitable for human consumption without treatment that meets or exceeds US EPA drinking water standards.
Off-gassing: the emission of volatile organic compounds from synthetic and natural products.
Pesticides Action Network (PAN): works to replace the use of hazardous pesticides with ecologically sound and socially just alternatives.
Pervious (surfaces): surfaces that limit disruption of natural hydrology by allowing moisture to pass through and soak into the earth thereby increasing infiltration and managing stormwater runoff.
Pesticide Action Network (PAN): promotes the elimination of highly hazardous pesticides and offers solutions that protect people and the environment.
Photovoltaics (PV): the field of technology and research related to the application of solar cells for energy by converting sunlight directly into electricity.
Post-consumer: Contains waste material generated by households or by commercial, industrial and institutional facilities in their role as end-users of the product, which can no longer be used for its intended purpose (e.g. items collected through curbside and drop-off recycling programs like used aluminum cans and newspaper).
Polyvinyl chloride (PVC): a relatively cheap and widely used chlorinated plastic, the manufacture of which involves the use of hazardous raw materials, including the basic building block of the plastic, vinyl chloride monomer (VCM) which is explosive, highly toxic and carcinogenic; disposal (e.g. incineration) involves the release of high chlorine content, which can contribute to the formation of highly toxic and persistent chlorinated dioxins.
Potable (water): water suitable for drinking and supplied from wells or municipal water systems.
Pozzolan: a material which, when combined with calcium hydroxide, exhibits cementitious properties; commonly used as an addition to Portland cement concrete mixtures to increase the long-term strength and other material properties of Portland cement concrete, and in some cases reduce the material cost of concrete.
Pre-consumer: Contains material diverted from the waste stream during the manufacturing process (e.g. sawdust, wood chips, sunflower seed hulls, newspaper print overruns).
R-value: a measure of thermal resistance (typically applied to insulation: the higher the R-value, the better the insulating effectiveness of the product).
Rapidly Renewable (materials): material considered to be an agricultural product, both fiber and animal, that takes 10 years or less to grow or raise, and to harvest in an ongoing and sustainable fashion.
Rated Power: the power available at a specified output of a device under specified conditions of operation (for example, if a wind turbine has a rated power or nameplate power of 10 kW, that tells you that the wind turbine will produce 10 kilowatt hours of energy per hour of operation, when running at its maximum performance, i.e. at top wind speeds).
Recovery Efficiency: How efficiently heat from the heat source is transferred to the water (typically applied to water heater technology).
Recycled Content: contains 25% or more of material that would otherwise be considered waste and placed in a landfill, either post-consumer or pre-consumer material, or a combination of the two.
Refrigerants: the working fluids of refrigeration cycles; absorb heat from a reservoir at low temperatures and reject heat at higher temperatures.
Regionally Produced: products that are manufactured nearby the region where their end-use will occur (most green building programs consider “nearby” as being within a radius of 500 miles); the use of which supports indigenous resources and reduces the environmental impacts resulting from transportation.
Restriction of the Use of Certain Hazardous Substances (ROHS): implements the EU Directive 2002/95, which bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl [PBB] and polybrominated diphenyl ether [PBDE] flame retardants.
Salvaged (material): material that is recovered from existing buildings or construction sites and reused in other buildings.
Seasonal Energy Efficiency Ratio (SEER): the efficiency of cooling units measured by the BTU of cooling output during a typical cooling-season divided by the total electric energy input in watt-hours during the same period (the higher the SEER rating, the more energy efficient the unit).
Sedimentation: the addition of soils to water bodies by natural and human-related activities (decreases water quality and accelerates the aging process of lakes, rivers and streams).
Sequestration (CO2): the storage of carbon dioxide in a solid material through biological or physical processes.
Short Chain Chlorinated Paraffins (SCCP): a category 3 carcinogen that have possible, serious, long-term adverse human, animal and plant health effects.
Siltation: to choke, fill, cover, or obstruct with silt or mud.
Soil Erosion: a form of soil degradation by which solids (sediment, soil, rock and other particles) are removed from the natural environment.
Solar Energy Factor: the energy delivered by the (solar thermal hot water heating) system divided by the electrical or gas energy put into the system; the higher the number, the more energy efficient the system.
Solar Fraction (SF): applied to solar water heaters to measure the portion of the total conventional hot water heating load (delivered energy and tank standby losses) provided by solar energy (the higher the SF is, the more the solar water heater is able to produce energy to heat water, thereby reducing the load on the back-up/conventional water heater).
Solar Heat Gain Coefficient (SHGC): measures how well a window blocks heat from sunlight; expressed as a number between 0 and 1 (the lower a window's SHGC, the less solar heat it transmits).
Solar Radiance: the amount of solar energy received on a given surface area in a given time, commonly expressed in kilowatt-hours per square meter per day (varies according to weather and latitude of the given location - applied to photovoltaic power systems).
Solar Reflectance: the ratio of the reflected solar energy to the incoming solar energy over wavelengths of approximately 0.3 to 2.5 micrometers (reflectance of 100% means that all of the energy striking a reflecting surface is reflected back into the atmosphere and none of the energy is absorbed by the surface).
Solar Reflectance Index (SRI): a measure of a material’s ability to reject solar heat (black is 0 and white is 100).
Stormwater Runoff: water volumes that are created during rain storms that flow over surfaces into sewer systems or receiving waters.
Sustainability: "to meet the needs of the present without compromising the ability of future generations to meet their own needs” (UN General Assembly, 1987).
Sustainably Harvested Wood: wood derived from forests that are managed using environmentally and socially responsible forest management practices, including the implementation of standards that assure forestry practices are environmentally responsible, socially beneficial and economically viable.
Thermal Break: refers to the implementation of a material that does not transmit heat well, such as plastic, with the purpose of reducing heat transfer through a window frame (typically are sandwiched inside the metal parts of the frame and can be used in the spacer between panes of glass in multi-pane windows as well as in the main body of the frame).
Toxicity: the degree to which a substance is able to damage an exposed organism.
U-factor/U-value: measures how well a product prevents heat from escaping (inverse of R-value); expressed as a number between 0 and 1 (the lower the U-value, the greater a product’s resistance to heat flow and the better its insulating value).
United States Green Building Council (USGBC): a 501(c)(3) non-profit community of leaders working to make green buildings available to everyone within a generation. Click here to view the USGBC's website.
Urea Formaldehyde: a combination of urea and formaldehyde that is used in some glues and may emit formaldehyde at room temperature, creating poor and potentially harmful breathing conditions.
Visual Transmittance (VT): measures how much light comes through a product; expressed as a number between 0 and 1 (the higher the VT, the more light is transmitted).
Volatile Organic Compounds (VOCs): carbon compounds that emit as gases from certain solids or liquids and include a variety of chemicals, some of which may have short- and long-term adverse health effects; concentrations are up to ten times higher than outdoors and often found in paints, pesticides, bonding agents and cleaning supplies.
Water Efficiency: using less water to provide the same level of water service.
Water Factor: the number of gallons per cycle per cubic foot that a product (typically a clothes washer) uses (the lower the water factor, the more efficient the product).
WaterSense®: a partnership program sponsored by the US EPA to protect the future of US water supply by promoting water efficiency and enhancing the market for water-efficient products, programs, and practices.
Watt: a unit of power equal to one joule of energy per second.
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