E&O Insurance: Errors and Omissions Insurance.

E. Coli: Escherichia coli is the most prevalent bacteria in the gastrointestinal tract of humans and animals. It occurs in solids and water as a result of fecal contamination.

Earmuff:  A hearing protector usually consisting of a headband and earcups.

Earnest Money: A sum paid to the seller to show that a potential purchaser is serious about buying.

Earplug:  A hearing protector worn within the external earcanal.

Earth Sheltered Design:  A home designed to be built partially or completely below ground, either by digging into existing ground or by covering over parts of the house. This design utilizes the constant temperature of the soil to improve energy efficiency and reduces environmental impact.

Earth’s Thermal Energy:  A little below the surface, the earth keeps a constant temperature close to the human comfort level, and this type of heating can be used efficiently for geothermal heating systems.

Earthquake Strap: A metal strap used to secure gas hot water heaters to the framing or foundation of a house. It is intended to reduce the chances of having the water heater fall over in an earthquake and causing a gas leak.

Easement: A formal contract which allows a party to use another party’s property for a specific purpose, e.g. a sewer easement might allow one party to run a sewer line through a neighbor’s property.

Eave: The part of the roof which extends beyond the side wall.
Eaves:  The edges of a roof system (See:  Soffit).

Eaves Flashing: Additional layer of roofing material applied at the eaves to help prevent damage from water backup.

Ebullator:  A device inserted in a flooded evaporator tubes to prevent the evaporator from becoming oil bound.

EC: Environment Canada.

Eccentric:  A disk mounted off center on a shaft. Ecliptic:  The great circle cut in the celestial sphere by an extension of the plane of the sun’s apparent orbit around the earth. The great circle drawn on a terrestrial globe makes an angle of about 23.27o with the equator.

Ecology:   The relationship of living things to one another and their environment.

Economizer:  This is an optional air conditioning accessory that utilizes fresh outside air during cooling requirements in mild weather (below 15 C). A controlled motorized damper simply opening and bringing in outdoor fresh air mixed to 15 C enables the user many benefits to reduce the need for mechanical cooling.

Ecosystem:  A complex system composed of a community of fauna and flora taking into account the chemical and physical environment with which the system is interrelated.

Eczema:  Pronunciation (ek′zĕ-mă, eg′zĕ-mă, eg-zē′mă).  Generic term for inflammatory conditions of the skin, particularly with vesiculation in the acute stage, typically erythematous, edematous, papular, and crusting; followed often by lichenification and scaling and occasionally by duskiness of the erythema and, infrequently, hyperpigmentation; often accompanied by sensations of itching and burning; the vesicles form by intraepidermal spongiosis; often hereditary and associated with allergic rhinitis and asthma.  [G. fr. ekzeō, to boil over].

Eddy Currents:  Induced currents flowing in a core. 

Edema: Swelling due to collection of fluid within cells or tissues.

Edge Cleaning:  This term refers to how well a vacuum cleaner is able to clean along “edges” such as walls and baseboards, furniture, etc. Because a vacuum cleaner has a housing that encloses the brush roll, special designs must be employed to enable successful edge cleaning. These include designing the brush roll so that bristles reach very close to the housing, stationary brushes mounted on the outside of the cleaning nozzle, air channels to increase airflow to edges as well as combinations of these approaches.

Edge Clearance: Nominal spacing between the edge of the glass product and the bottom of the glazing pocket (channel).

Edge Grain (Vertical): Edge-grain lumber has been sawed parallel to the pith of the log and approximately at right angles to the growth rings; i.e., the rings form an angle of 45° or more with the surface of the piece.

Edge Metal: A term relating to brake or extruded metal around the perimeter of a roof.

Edging Strips: Boards nailed along eaves and rakes to provide secure edges for re-roofing with asphalt shingle after cutting back existing wood shingles.

EER:  Acronym for Energy Efficiency Ratio. This is a measurement of the efficiency of the cooling unit. It is calculated by comparing the Btu’s to the watts of electricity consumed and the higher the efficiency rating the more efficient the unit. This benefits both environment and consumer as less energy is used which results in a lower operating costs.

E-Field (Electric field):  The dominant component of a high impedance lectromagnetic field produced by a near-field source such as a short diapole, or the electric component of a far-field plane wave. Expressed in V/m.

Effective Area:  The area (in sq inches) of the filter element that is exposed to the flow of air or fluid for effective filtering.

Effective Dose Equivalent (EDE):  Estimate of the total risk of potential effects from radiation exposure, it is the summation of the products of the dose equivalent and weighting factor for each tissue. The weighting factor is the decimal fraction of the risk arising from irradiation of a selected tissue to the total risk when the whole body is
irradiated uniformly to the same dose equivalent. These factors permit dose equivalents from nonuniform exposure of the body to be expressed in terms of an effective dose equivalent that is numerically equal to the dose from a uniform exposure of the whole body that entails the same risk as the internal exposure (ICRP 1980).  The effective dose equivalent includes the committed effective dose equivalent from internal deposition of
radionuclides and the effective dose equivalent caused by penetrating radiation from sources external to the body, and is expressed in units of rem (or sievert).

Effective Filtration Area: The portion of filter that fluid flows through during the filtration process.

Effective Temperature:  The temperature of a black enclosure at 50% relative humidity (sea level), in which a solid body or occupant would exchange the same heat by radiation, convection, and evaporation as in the existing non-uniform environment.

Efficacy:  The number of lumens produced by a watt used for lighting a lamp. Used to describe lighting efficiency.

Efficiency:  Ability of a filter to remove particle matter from an air stream. Measured by comparing concentrate of material upstream and downstream of the filter. Typical particulate sizes range from .3 micron to 50 micron.

Efficiency Compression:  The ratio of the theoretical work requirement to the actual work required to be performed on the gas for compression and delivery.

Efficiency Isothermal:  The ratio of the theoretical work calculated on an isothermal basis to the actual work transferred to the gas during compression.

Efficiency Mechanica:  The ratio of the thermodynamic work requirement in the cylinder to actual brake horsepower requirement.

Efficiency Polytropic:  The ratio of the polytropic compression energy transferred to the gas to the actual energy transferred to the gas.

Efficiency Volumetric:  The ratio of actual capacity to piston displacement, stated as a percentage.

Efflorescence: A white powder on the surface of walls due to evaporation of water. It forms on the surface of bricks.

Effluent:  Solid, liquid or gaseous wastes that enter the environment as a by-product of human-oriented processes; or water that has undergone treatment to remove pollutants.

Effluent Limitation:  Any restriction established on quantities, rates and concentrations of chemical, physical, biological, and other constituents which are discharged from point sources into navigable waters, the waters of the contiguous zone, or the ocean, including schedules of compliance. The restriction may be narrative or numeric.

Egress: A means of exiting the home. An egress window is required in every bedroom and basement. Normally a 4x4 window is the minimum size required.

EHM:  Extremely Hazardous Material. Such materials are listed in Attachment V. They are orders of magnitude more hazardous than those listed as High Hazard Substances.

EH&S:  Office of Environmental Health and Safety of the Health Science Campus of Columbia University in the City of New York. It is the department charged with the development and implementation of programs in industrial hygiene, laboratory safety, hazardous materials control, biohazards regulation, safety engineering and environmental protection for the Health Sciences Campus.

Eight-Hour Ozone Standards:  Since 1971, the U.S. Environmental Protection Agency (EPA) has established national air quality standards for ozone. Revised in 1997, the current national air quality standard for ozone is 0.08 parts per million (ppm), or 80 parts per billion (ppb), averaged over 8 hours. For a given geographic area to be in compliance, its fourth highest 8-hour concentration in a year, averaged over three years, must be equal to or less than that amount.

Ejector:  A device which uses high fluid velocity, such as a venturi, to create low pressure or vacuum at its throat to draw in fluid from another source.

Ejector Compressor:  A compressor belonging to the group of dynamic compressors.

Elastomer: An elastic rubber-like substance, such as natural or synthetic rubber.

Elastomeric: Of or pertaining to any of the numerous flexible membranes that contain rubber or plastic.

Elastomeric Facepiece:  A respirator facepiece that is made of flexible materials, such as rubber, silicone, or neoprene.

Elbow: An angled fitting that alters the direction of the water line.

Elecrodialysis:  Dialysis (small molecules separated from larger molecules in the same solution/mixture) accelerated by an electromotive force applied to electrodes adjacent to the separating membranes.

Electret:  A dielectric body in which a state of electric polarization is established. An imposed electric field on heated polyolefin following the drawing stage to form a charged fiber or yarn with electrostatic like properties. These properties may decay or by contamination by solvents and materials.
Electret Air Filter: An Electret Air Filter is a type of electronic air filter. The filter, known as an Electret, is given a positive charge that causes airborne particles to stick to it as they pass through.
Electric Defrosting:  Use of electric resistance heating coils to melt ice off evaporators. 

Electric Heating:  Heating using electric resistance heaters. 

Electric Hose:  Canister vacuum cleaners that use power nozzles need to get electrical power to the motorized cleaning head. In the past this was done by attaching an electric cord to the outside of the vacuum hose and then down the wands with special straps. An electric vacuum hose is manufactured so that the electrical wires are internal. This eliminates the inconvenience of external cords and makes using the vacuum cleaner much more enjoyable. 

Electric Lateral: The trench or area in the yard where the electric service line (from a transformer or pedestal) is located, or the work of installing the electric service to a home.

Electric Motor Brush:  This is a Bosch trade name for their power nozzle. See “Power Nozzle.”

Electric Power Display:  This is an electrical display that indicates at a glance the level of power at which the vacuum cleaner is operating.

Electric Resistance Coils: Metal wires that heat up when electric current passes through them and are used in baseboard heaters and electric water heaters.

Electric Vehicle: A motor vehicle that uses an electric motor as the basis of its operation. Such vehicles emit virtually no air pollutants. (See also hybrid electric vehicle.)

Electricity Supplier:  As states restructure their electricity markets, an increasing number of customers will be able to choose from a range of energy suppliers who market different types of power products, including green power from renewable energy. Restructured local utilities offer electricity products generated exclusively from renewable resources or, more frequently, electricity produced from a combination of fossil and renewable resources. In states without restructured electricity markets, local utilities may offer green pricing programs, where customers may elect to have their utility generate a portion of their power from renewable sources.  To find out about green power products in your area, refer to the Green Power Locator.

Electrical Conductivity:  The relative ability of water to conduct electrical current. It depends on the ion concentration and can be used to approximate the total filterable residue (total dissolved solids) in the water.

Electrical Entrance Package: The entry point of the electrical power including: (1) the ‘strike’ or location where the overhead electrical lines connect to the house. (2) The meter which measures how much power is used. (3) The ‘panel,’ ‘circuit breaker box’ or ‘fuse box’ where the power can be shut off and overload devices such a fuses or circuit breakers and located.

Electrical Rough: Work performed by the Electrical Contractor after the plumber and heating contractor are complete with their phase of work. Normally all electrical wires, and outlet, switch, and fixture boxes are installed (before insulation).

Electrical Trim: Work performed by the Electrical Contractor when the house is nearing completion. The electrician installs all plugs, switches, light fixtures, smoke detectors, appliance “pig tails,” bath ventilation fans, wires the furnace, and “makes up” the electric house panel. The electrician does all work necessary to get the home ready for and to pass the municipal electrical final inspection.

Electrocardiogram (EKG): A tracing of the heart’s electrical activity. Can show heart strain and heart disease.

Electrochemical: A process by which electricity is used to effect chemical reaction. The inter-conversion of chemical and electrical energy.

Electrodepositing Process:  Process in which metallic particles are applied to another metal surface through the use of an electric current.

Electrolysis:  Movement of electricity through a substance which causes a chemical change in the substance or its container.

Electrolyte:  Substances which will conduct an electrical current, either in molten state or in a solution e.g. NaCl in water.

Electrolytic Coupling: A fitting required to join copper to galvanized pipe and gasketed to prevent galvanic action. Connecting pipes of different materials may result in electrolysis.

Electromagnet:  A coil of wire wrapped an iron core. When electric current flows through wire, the assembly becomes a magnet.

Electromagnetic Capability (EMC):  The capability of electronic equipment on systems to be operated in the intended operational electromagnetic environment at designed levels of efficiency.

Electromagnetic Energy:  Energy that has both electrical and magnetic characteristics.

Electromagnetic Interference (EMI):  Electromagnetic energy that causes interference in the operation of electronic equipment. Can be conducted, coupled or radiated. Can be natural or man-made.

Electromagnetic Radiation: (1.) emission or transfer of energy in the form of electromagnetic waves or photons, (2.) these electromagnetic waves or these photons.

Electron:  The portion of an atom that carries a negative charge.

Electronic Adjustable Power Regulation:  See “Electronic Suction Adjustment.”

Electronic Air Cleaner (EAC):  Electronically filters out magnetized airborne particles, from contaminants in indoor air sending them to a collector plate.

Electronic Air Purifier: Electronic air purifiers do not use air filters like conventional air purifiers. Instead, they use electricity to charge the air traveling though them. Electronic air purifiers come in three basic types: Negative Ionizing Purifiers, Electret Air Filters, and Electrostatic Precipitators.

Electronic Control Diagnostics:  Trouble codes that may be referenced on an automatic climate control system to diagnose problems.

Electronic Leak Detector:  An electronic instrument that measures electronic flow across gas gap. Electronic flow changes indicate presence of refrigerant gas molecules.

Electronic Relay:  A relay that is mounted on a circuit board and is controlled by a electronic signal, such as a triac. 

Electronic Sight Glass:  A electronic device that detects the presence of vapor in the liquid. 

Electronic Suction Adjustment:  There are two ways that vacuum suction can be adjusted; reducing the power to the vacuum motor or opening a relief valve that bypasses air and lowers the suction at the tool. Electronic Suction Adjustment refers to the reduction of power to the motor, which slows it down and in turn reduces suction. Also referred to as a “Speed Control.”

Electronic Thermistor:  A temperature sensitive resistor used on electronic thermostats. 

Electronic Thermostat:  A thermostat that uses electronic components to accomplish various sensing, switching, timing, staging and display functions. 

Electronics:  Field of science dealing with electron devices and their uses. 

Electrophoresis: The separation of charged molecules (such as proteins) based on their mobility in an electrical field.

Electrostatics:  Electrical charges on particles and/or fibers in a filter medium create attractive and/or repulsive forces between particles and the fiber/medium. As a direct result, for many types of particles, strong attractive forces produce the intimacy needed to agglomerate even the fines.

Electrostatic or Electrostatically Charged:  At this moment, you’re reading this web page through a thin layer of dust on your computer screen, and no matter what you do, or how many times you clean it off, the dust will always come back. Why? It’s a simple matter of Physics. Because of its design, a computer screen has a positive electrical charge, and the dust you're reading through happens to be negatively charged. And remember . . . when it comes to electrical charges, opposites attract!  An electrostatically charged air filter uses this principle to capture even more dust than a regular filter - in effect; the electrostatic filter becomes a “dust magnet.”   

Electrostatic Filter:  A filter that is made up of synthetic fibers that develop an electrostatic charge as friction is applied, which in vacuum cleaners, air purifiers and furnace filters is produced by air flowing across the filter. This electrostatic charge is generally effective in trapping particles 1 micron or larger making electrostatic filters capable of capturing house dust, skin flakes, animal dander, pollen and mold spores.

Electrostatic Filter Media: The concept of electrostatically charging a filter media (often called an electret) was discovered in 1931 and has been used to enhance filter media efficiency since then.  Most modern electrostatically charged filter medias are produced from polymeric (synthetic) materials.  Many polymers will become charged during the process of converting them to fibers and filter media.  This charge is often short lived.  Fibers of different polymers can be combined in a filter media to create a “triboelectric” charge.  Again, this electrostatic charge may not last long in a filter.  Another method of creating an electrostatic filter media is by corona discharge, which creates fibers of opposite charge in cross section.  In all cases, particles of an opposite charge to the attracting filter media fiber or particles with a dipole (oppositely charged ends) are attracted to the filter media fibers in a similar way to dust being attracted to a television screen.

Electrostatic Precipitators: Electrostatic Precipitators are special electronic filters that use a fan to blow air into a cell where it is given a positive electrical charge. The air is then blown through special aluminum plates which carry a negative charge and attract nearly all of the durst and debris. Since they do nothing to destroy viruses, spores, and molds, however, these plates can become a breeding ground for airborne organisms.

Element:  The medium or material that does the actual filtering or separating. May be paper, wire mesh, special cellulose, inorganic plastic, or a combination.

Elevated Temperature Waste:  Liquid, solid, or gaseous material including thermal waste discharged at a temperature higher than the natural temperature of receiving water.

Elevation: A side of a building.

Elevation Sheet: The page on the blue prints that depicts the house or room as if a vertical plane were passed through the structure.

Eligible Multi-Family Dwelling Units:  A multi-family building qualifies to be weatherized in its entirety when 66% (50% for 2 and 4 unit buildings) or more of the total dwelling units in the building are determined to be eligible as per DOE rules.

Eligible Unit:  A unit occupied by a household that is categorically eligible or income eligible by DOE and/or LIHEAP standards.

Elimination Diet:  A diet designed to detect what ingredient of the food causes allergic manifestations in the patient; food items to which the patient may be sensitive are withdrawn separately and successively from the diet until the item that causes the symptoms is discovered.

Ell: See Elbow.

ELSI:  End of Service Life Indicator is used on a chemical cartridge to indicate when the cartridge should be discarded and replaced by showing a colorimetric change on the cartridge.  This color change takes place before the contaminant breaks through the cartridge.

Embodied Energy:  The energy that is necessary to make a product. It is also the molecular energy already existing in a product’s content.

Emergency Asbestos Project:  An asbestos project which is necessary to respond to an emergency. 

Emergency Heat (Supplemental or Auxiliary Heat):  The back-up heat built into a heat pump system.

Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA):  Act that requires facilities that produce, use, or store hazardous substances to report releases of reportable quantities or hazardous substances to the environment.

Emergency shower: A unit that enables a user to have flushing fluid cascading over the entire body.

Emergent Wetland:  Wetlands dominated by erect, rooted, herbaceous aquatic plants (e.g. cattails, bulrush, etc.), which extend above the standing water level. 

EMF:  Electromotive force. Symbol : E. Unit : volt. It’s the property of electrical energy that causes current to flow.

Emission:   Pollution discharge from a source.

Emission Factor: For stationary sources, the relationship between the amount of pollution produced and the amount of raw material processed or burned. For mobile sources, the relationship between the amount of pollution produced and the number of vehicle miles traveled. By using the emission factor of a pollutant and specific data regarding quantities of materials used by a given source, it is possible to compute emissions for the source. This approach is used in preparing an emissions inventory.

Emission Inventory: An estimate of the amount of pollutants emitted into the atmosphere from major mobile, stationary, area-wide, and natural source categories over a specific period of time such as a day or a year.

Emission Offsets (also known as Emissions Trading): A rule-making concept whereby approval of a new or modified stationary source of air pollution is conditional on the reduction of emissions from other existing stationary sources of air pollution. These reductions are required in addition to reductions required by best available control technology.

Emission Rate: The weight of a pollutant emitted per unit of time (e.g., tons / year).

Emission Standard: The maximum amount of a pollutant that is allowed to be discharged from a polluting source such as an automobile or smoke stack.

Emissivity:    The ratio of the radiant energy emitted from a surface at a given temperature to the energy emitted by a black body at the same temperature.

Emittance:  The ability of a material to emit radiant energy from its surface. Also called emissivity.

Emitter:  The lead of a transistor shown using an arrow with a head on it. 

Emphysema: The destruction, or breakdown, of the walls of the alveoli located at the end of the bronchial tubes. The damaged alveoli are not able to exchange oxygen and carbon dioxide between the lungs and the blood. The bronchioles lose their elasticity and collapse during exhalation, trapping air in the lungs. The trapped air keeps fresh air and oxygen from entering the lungs.

EMT (Electrical Metallic Tubing): Electrical pipe, also called thin-wall conduit, which may be used for both concealed and exposed areas. It is the most common type of raceway used in single family and low rise residential and commercial buildings.

Emulsibility:  The ability of a non-water-soluble fluid to form an emulsion with water.

Emulsifier:  Additive that promotes the formation of a stable mixture, or emulsion, of oil and water. Common emulsifiers are: metallic soaps, certain animal and vegetable oils, and various polar compounds.

Emulsion:  Intimate mixture of oil and water, generally of a milky or cloudy appearance. Emulsions may be of two types: oil-in water (where water is the continuous phase) and water-in-oil (where water is the discontinuous phase).

Encapsulation:  The sealing of a malodor causing substance preventing further odor escape.

Encephalitis:  Refers to infection or inflammation of the brain. Ascending encephalitis refers to an infection of the nervous tissue that travels up towards the brain and eventually affects the brain too.

Enclosed Bays:  Indentations along the coast that enclose an area of oceanic water within a distinct headlands or harbor works. Enclosed bays include all bays where the narrowest distance between headlands or outermost harbor works is less than 75 percent of the greatest dimension of the enclosed portion of the bay.

Enclosure: Abatement consisting of the construction of airtight walls, ceilings and floors between the asbestos material and the building/structure environment, or around surfaces coated with asbestos material, or any other appropriate procedure as determined by the Department, which prevents the release of asbestos fibers.

End Bell:  The plates on the ends of a electric motor which usually holds motor bearings. 

End Cap:  A ported or closed cover for the end of a filter element.

End Dams: Internal flashing (dam) that prevents water from moving laterally within a curtain wall or window wall system.

End Lap: The amount or location of overlap at the end of a roll of roofing felts in the application.

End of Service Life Indicator  (ESLI):  A system that warns the respirator user of the approach of the end of adequate respiratory protection; for example, a device that shows that a sorbent is approaching saturation or is no longer effective; refer to CSA Z94.4 for the definition.

End Play:  The movement of the motors shaft along its centerline. 

Endangered Species:  Animal populations are be determined to be endangered when populations are severely depleted, as defined by the Endangered Species Act.

Endocrine System: The endocrine system is a series of glands that secretes hormones into the bloodstream to regulate your body's processes. The main endocrine glands are: adrenal, ovary, pancreas, pituitary, testes, and thyroid.

Endorphins:  Endorphins are a group of small proteins naturally occurring in the brain around nerve endings that bind to opiate receptors and thus can raise the pain threshold. Enkephalins are included in this group of compounds.

Endoscopy:  Pronunciation (en-dos′kŏ-pē).  Examination of the interior of a canal or hollow viscus by means of a special instrument, such as an endoscope. See: endoscope.

Endothermal:  Chemical reaction in which heat is absorbed. 

Endotoxin: A toxic substance produced by bacteria, but which is released into the surrounding medium only upon the death or disintegration of the bacteria.

Endpoint:  The term “endpoint” can be defined as the point at which an experimental animal's pain and/or distress is terminated, minimized or reduced by taking actions such as humanely killing the animal, terminating a painful procedure, or giving treatment to relieve pain and/or distress.

Energy:  A quantity of heat or work.

Energy Audit:  A survey that shows how much energy you use in your compressed air generation. It will help find ways to use energy more efficiently.

Energy Conservation:  Practices and measures that increase energy efficiency.

Energy Consumption:  The conversion or transformation of potential energy into kinetic energy for heat, light, electricity, etc.

Energy Content: The amount of energy available for doing work. For example, the amount of energy in fuel available for powering a motor vehicle.

Energy Demand: Amount of energy required (e.g. for indoor climate control).

Energy Education:  The process used by WAP staff to inform customers of the ways they can further reduce energy consumption through altering their behavioral patterns. The most effective protocol includes multiple interaction and reinforcement with the household residents and use of a negotiated and written action plan.

Energy Efficiency:  Term used to describe how efficiently a building component uses energy.

Energy Efficiency Ratio (EER):  A measurement of energy efficiency for room air conditioners. The EER is computed by dividing cooling capacity, measured in British Thermal Units per hour (Btuh), by the watts of power. (See:  Seasonal Energy Efficiency Rating or SEER).

Energy Kinetic:  Is the energy a substance possesses by virtue of its motion or velocity. Used primarily in calculations for dynamic and ejector type compressors.

Energy Modeling:  A computer model used to analyze a building’s energy systems in order to project its possible consumption rate.

Energy Recovery:  A process of attaining energy from waste.

Energy Recovery Ventilation System:   A device or combination of devices applied to provide the outdoor air for ventilation in which energy is transferred between the intake and exhaust airstreams.

Energy Recovery Ventilator (also FreshEffects™ or TRANE FreshEffects™):  Energy efficient system to exchange stale indoor air for an equal amount of fresher outdoor air.

Energy Saver Switch:  An energy-saver switch causes the air conditioner’s fan and compressor to cycle on and off together, reducing energy use.

Energy Source: The primary source that provides the power that is converted to electricity through chemical, mechanical, or other means. Energy sources include coal, petroleum and petroleum products, gas, water, uranium, wind, sunlight, geothermal, and other sources.

ENERGY STAR®:  Trane high efficiency systems carry the ENERGY STAR label. The result of Trane’s partnership with the U.S. Department of Energy, Environmental Protection Agency (EPA), ENERGY STAR products are more energy efficient and help reduce our whole earth’s pollution problems. Choosing a Trane ENERGY STAR Comfort System assures homeowners of lower energy bills and improved indoor air quality for their home.

Energy Storage:  The ability to convert energy into other forms, such as heat or chemical reaction, so that it can be retrieved for later use. Also the development, design, construction and operation of devices for storing energy until needed. Technology includes devices such as compressed gas.

Energy Use: The amount of energy used (e.g. for indoor climate control), including losses of the installation.

Energy Use for Cooling: See cooling load.

Energy Use for Heating: The amount of energy needed to cover the heating demand, including losses of the installation.

Enhanced Recovery of Coalbed Methane (ECBM): The process of injecting a gas (carbon dioxide or nitrogen) into deep and unmineable coalbeds in order to stimulate methane production.

Enteric:  Intestinal; of the enteron.

Enteric Fermentation:  The natural digestive process in ruminant animals (e.g. cattle and sheep) that produces methane as a by-product.

Enter: To go into an area to observe all visible components.

Enterococcus:  A streptococcus (bacteria) normally present in the intestinal tract (of humans and warm blooded animals), may cause illness when found in other parts of the body.

Enthalpy:  Is the sum of the internal and external energies.

Entrained Water:  Discrete water droplets carried by a continuous liquid or gas phase when water is immiscible with the liquid.

Entrainment Ratios:  Are used with ejectors to convert weight of gas and/or water vapor handled to or from equivalent air.

Entropy:  Is a measure of the unavailability of energy in a substance.

Envelope:  The exterior surface of a building including all external additions e.g. chimneys, bay windows, etc.

Environment:   The sum of all external conditions affecting the life of an organism.

Environmental Agents:  Conditions other than indoor air contaminants that cause stress, comfort, and/or health problems (e.g., humidity extremes, drafts, lack of air circulation, noise, and over-crowding).

Environmental Contaminant:  All material and energy present in and around an operating system, such as dust, air moisture, chemicals, and thermal energy.

Environmental Controls:  Means by which the physical environment can be controlled: these may be active, e.g. heating or cooling systems, fans etc which use energy, or passive, such as openable windows, blinds, etc.

Environmental Factors:   Conditions other than indoor air contaminants that cause stress, comfort, and/or health problems (e.g., humidity extremes, drafts, lack of air circulation, noise, and over-crowding).

Environmental Impact Report (EIR):  A document required by the 1970 California Environmental Quality Act (CEQA) that assesses the possible environmental effects of a project.

Environmental Impact Statement (EIS):  Required by the National Environmental Policy Act, this document analyzes the effects of major federal projects on the environment. It must be filed with the President and the Council on Environmental Quality, and must be made available to the public.

Environmental Justice: The fair treatment of people of all races and incomes with respect to development, implementation, and enforcement of environmental laws, regulations, and policies.

Environmental Tobacco Smoke (ETS):  Mixture of smoke from the burning end of a cigarette, pipe, or cigar and smoke exhaled by the smoker (also secondhand smoke (SHS) or passive smoking).

Environmental Variables (Thermal Environment): Thermal characteristics of the environment; generally the air temperature (Ta), the radiant temperature (Tr), the water vapour pressure (Pa) (or humidity) and the air velocity (Va).

Enzyme:  A protein used to fuel the reaction of “good” bacteria digesting urea crystals in urine contamination treatments.

Enzyme-Linked Immunosorbent Assay (ELISA):  An in vitro binding assay in which an enzyme and its substrate (rather than a radioactive substance) serve as the indicator system; in positive test results, the two yield a colored or other easily recognizable substance; tests are made in wells in polystyrene or other material to which immunoglobulins or antigenic preparations readily adsorb; the enzyme is linked to known immunoglobulin (or antigen) and in positive test results remains in the well as part of the antigen-antibody complex available to react with its substrate when added.

Eosinophil:  Pronunciation (ē′ō-sin′ō-fil, -fīl).  Syn: eosinophilic leukocyte.  [eosin + G. philos, fond].

Eosinophils, Neutrophils, Lymphocytes:  These are different cell types in the white blood cell series. Their numbers change in many conditions such as disease, distress, toxic states. White blood cell counts are useful for diagnostic purposes.

EPA:   U.S. Environmental Protection Agency.

EPA Synthetic Moderately Hard Water:  Water solutions prepared according to U.S. EPA standards used as a reference water sample for control comparisons in whole effluent toxicity testing. Synthetic waters are prepared in accordance with Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to
Freshwater Organisms, EPA-821-R-02-013 (U.S. EPA 2002).

EPDM (Ethylene Propylene Diene Monomer): A single ply membrane consisting of synthetic rubber; usually 45 or 60 mils. Application can be ballasted, fully adhered or mechanically attached.

Ephemeral Stream:  Carries water runoff only in times of rainfall and remains as a dry channel during the rest of the year.

Epidemic:   Widespread outbreak of a disease.

Epidemiology: The study of the occurrence and distribution of disease within a population.

Epidermis:  The outer layer of human skin, composed of a thin layer of epithelial cells.

Epidural:  The epidural space is the space around the spinal cord. Epidural anesthesia is produced by injecting the analgesic drug (usually a local anesthetic, but it could also be an opioid) into the epidural space, usually in the lumbar region. The drug directly affects the spinal cord or the nerve roots arising from the cord.

Epinephrine:  Pronunciation (ep′i-nef′rin).  A catecholamine that is the chief neurohormone of the adrenal medulla of most species; also secreted by certain neurons. The l-isomer is the most potent stimulant (sympathomimetic) of adrenergic α- and β-receptors, resulting in increased heart rate and force of contraction, vasoconstriction or vasodilation, relaxation of bronchiolar and intestinal smooth muscle, glycogenolysis, lipolysis, and other metabolic effects; used in the treatment of bronchial asthma, acute allergic disorders, open-angle glaucoma, cardiac arrest, and heart block, and as a topical and local vasoconstrictor. Generally used salts are epinephrine hydrochloride and epinephrine bitartrate, the latter most frequently used in topical preparations. See also: emergency theory, fight or flight response.  Syn: adrenaline.  [epi- + G. nephros, kidney, + -ine].

Episode: A period of markedly worsened symptoms. This may be brought on by exposure to a known trigger or by an upper respiratory infection (a cold), or it may not have a known explanation. An episode may come on all of a sudden or may develop gradually over days. Asthma episodes, at their worst, can be life threatening, and should always be taken seriously.

Episodic: Intermittent, with periods of apparent normal function in-between periods of symptoms.

Epoxy Seal:   A two-part coating system for sealing concrete. Because of the application difficulty, Epoxy seal is only used for new construction before the raised floor is installed.

Equilibrium Moisture Content (EMC):  When wall logs have reached a condition in which their moisture content is constant in relation to the relative humidity and temperature of the surrounding air, it is said that they have reached Equilibrium Moisture Content.

Equity: The “valuation” that you own in your home, i.e. the property value less the mortgage loan outstanding.
Equivalent Leakage Area (ELA):  Calculation, in square inches, of the total area of all holes and cracks in a structure. The leakage area is then accumulated to represent one total leakage point.

Ergogrip Plus™ Handle:  A Bosch trade name for their ergonomically designed hose handle. See “Ergonomic.”

Ergonomics:   The study of people adjusting to their work environment; the science of adapting working conditions to the worker.

Erosion:  Wearing away of earth and rock by running water, glaciers, winds, and waves.

Erythema:  Pronunciation (er′i-thē′mă).  Redness due to capillary dilation, usually signaling a pathologic condition (e.g., inflammation, infection). Cf.: telangiectasia.  [G. erythēma, flush].
 
Esacerbation: Any worsening of symptoms. Onset can be acute and sudden, or gradual over several days. A correlation between symptoms and peak flow is not necessarily found. Exacerbation replaces the words “attack” and “episode.”

Escape-Only Respirator:  A respirator intended to be used only for emergency exit, and not for work.

Escherichia Coli (E. Coli):  One of the group of bacteria referred to as fecal coliforms.

Escrow: The handling of funds or documents by a third party on behalf of the buyer and/or seller.

Escutcheon: A trim piece or decorative flange that fits beneath the faucet handle to conceal the faucet stem and the hole in the fixture or wall.

ESLI:  See end of service life indicator.

Estimate: The anticipated cost of materials, labor, and associated cost for a proposed construction, repair, or remodeling project.

Estimating: The process of calculating the cost of a project. This can be a formal and exact process or a quick and imprecise process.

Estrogen: Any of several steroid hormones produced chiefly by the ovaries and responsible for promoting estrus and the development and maintenance of female secondary sex characteristics.

Estuary:  Water at the mouth of a stream that serves as mixing zones for fresh and ocean waters during a major portion of the year. Estuarine waters generally extend from a bay or the open ocean to the upstream limit of tidal action but may be considered to extend seaward if significant mixing of fresh and salt water occurs in the open coastal waters. (Basically, where a freshwater river meets the sea.)

Ethane Gas:  The fossil fuel, natural gas, used for heat.

Ethanol: Ethyl-alcohol, a volatile alcohol containing two carbon groups (CH3CH2OH). For fuel use, ethanol is produced by fermentation of corn or other plant products.

Etiology:   The science of causes or origins; the cause of a specific disease.

Etiological:  Pertaining to the cause of a disease or abnormal condition.

Etiological Agent:  Organism or substance that causes a disease.

Eto Sterilization:  Chemical sterilization using ethylene oxide at an elevated temperature of 1500 º F and high relative humidity to facilitate permeation of the ethylene oxide into the material being sterilized.

ETS:   Environmental tobacco smoke.

Eutectic:  That certain mixture of two substances providing lowest melting temperature of all the various mixes of the two substances.

Eutectic Point:  Freezing temperature for eutectic solutions. 

Euthanasia:  To kill an animal painlessly, and without distress.

Eutrophication:  The slow aging process during which a lake, estuary, or bay evolves into a bog or marsh and eventually disappears. During the later stages of eutrophication the water body is choked by abundant plant life due to higher levels of nutritive compounds such as nitrogen and phosphorus. Human activities can accelerate the process.

Evacuation:  The removal of contaminants in a refrigeration system.

Evaluate: To assess the systems, structures or components of a dwelling.

Evaporation:  The escape of water molecules from a liquid to the gas phase at the surface of a body of water.

Evaporation Rate:  The ratio of the time required to evaporate a measured volume of a liquid to the time required to evaporate the same volume of a reference liquid (butyl acetate, ethyl ether) under ideal test conditions. The higher the ratio, the slower the evaporation rate. The evaporation rate can be useful in evaluating the health and fire hazards of a material.

Evaporative Condenser:  One that utilizes the evaporation of water by air at the condenser surface as a means of heat dissipation.

Evaporative Cooler:  A device for cooling homes in dry climates by humidifying and cooling incoming air.

Evaporative Emissions: Emissions from evaporating gasoline, which can occur during vehicle refueling, vehicle operation, and even when the vehicle is parked. Evaporative emissions can account for two-thirds of the hydrocarbon emissions from gasoline-fueled vehicles on hot summer days.

Evaporative Systems:  Falling under the cool mist category there are several types of evaporative humidifiers. The most basic utilize a filter pad to absorb water and a fan that blows air across the pad to release moisture into the air. More advanced systems such as those made by Venta and Air-O-Swiss utilize special evaporative discs and do not require pads.

Evaporator:  The chamber located on suction side of cap tube, in which freon is evaporated to cause cooling in a refrigeration system.

Evaporator Coil:  Copper or aluminum tubing situated in the indoor or air handling unit. Liquid refrigerant from the condenser coils is pumped into these coils and evaporates into a vapor as it absorbs heat from warm room air. The air is circulated over the coils by the fan and, once relieved of its excess heat, is pumped back into the room.

Evaporator, Dry Type:  Evaporator in which the refrigerant is in the liquid droplet form. 

Evaporator Fan:  A mechanical device that increases airflow over the heat exchange surface of evaporators.

Evaporator, Flooded:  Evaporator containing liquid refrigerant at all times. 

Evapotranspiration:  Process by which water is transferred from the soil to the air by plants that take the water up through their roots and release it through their leaves and other aboveground tissue.

EVR:   Effective ventilation rate; the ventilation rate based on the actual quantity of outdoor air delivered to the occupied areas of a building or space.

EWT:  Entering water or fluid temperature.

Ex Vivo:  Outside the living body, for example removing a liver for studies in a perfusion apparatus.

Exacerbation: Worsening.

Examine: To visually look. See Inspect.

Excavate: To dig the basement and/or all areas that will need footings/foundations below ground.

Exceedance: A measured level of an air pollutant higher than the national or state ambient air quality standards. (See also NAAQS and CAAQS.)

Exercise-Induced Asthma: Asthma triggered by exercise. In some people, it is their only trigger.

Exfiltration:   Air leakage outward through cracks and interstices and through ceilings, floors, and walls of a space or building.

Exhalation: Breathing air out of the lungs; expiration.

Exhaust Air:   Air removed from a space and not used therein.

Exhaust Fan: Extracts air or excess heat from the interior of a home.

Exhaust Gas Recirculation (EGR): An emission control method that involves recirculating exhaust gases from an engine back into the intake and combustion chambers. This lowers combustion temperatures and reduces NOx. (See also nitrogen oxides.)

Exhaust Gas Recirculation System (EGR):  The controlled diversion of some of the combustion gases back into the combustion chamber, lowering the combustion temperature and reducing nitrogen oxides in the engine. This is a very effective process, because oxides of nitrogen tend to rise disproportionately with increased combustion temperatures. There are two methods of exhaust gas recirculation internally through overlap of valve opening times and externally with recirculation valves and manifolds.

Exhaust Port:  That opening which carries the fluid to the downstream pressure of a fluid system.

Exhaust Ventilation: Mechanical removal of air from a portion of a building (e.g. piece of equipment, room, or general area).

Existing Discharge:  Any discharge (a) which is presently taking place, or (b) for which waste discharge requirements have been established and construction commenced, or (c) any material change in an existing discharge for which construction has commenced. 

Exothermal:  A chemical reaction in which heat is released.

Exothermic:  A term used to describe a chemical process in which heat is released. For example, combustion is an exothermic process because heat is released.

Exotoxin:  Diffusible toxins produced by certain Gram-positive bacteria. Exotoxins are present in the filtrates of growing cultures in which no appreciable autolysis has occurred.

Expanded Polystyrene (EPS):  Insulation comprised of polystyrene resin processed to form a rigid foam.  Foam boards or blocks are formed during expansion.

Expanders:  Turbines or engines in which gas expands, does work, and undergoes a drop in temperature.

Expansion Coefficient: The amount that a specific material will vary in any one dimension with a change of temperature.

Expansion Joint: A device used to permit a structure to expand or contract without breakage. In residential construction, a bituminous fiber strip used to separate blocks or units of concrete to prevent cracking due to expansion as a result of temperature changes. Also used on concrete slabs.

Expansion Valve:  This device controls the temperature and pressure of the refrigerant preventing damage to the compressor.

Expansive Soils: Earth that swells and contracts depending on the amount of water that is present.

Expected Peak Day Concentration (EPDC): A calculated value that represents the concentration expected to occur at a particular site once per year, on average. The calculation procedure uses measured data collected at the site during a three-year period. Measured concentrations that are higher than the EPDC are excluded from the state area designation process.

Expectorant: Medication that helps to thin mucus in the airways so it can be coughed out more easily. These medications should be taken with at least 8 ounces of water.

Expendable Refrigerant System:  A system which discards the refrigerant after it has evaporated.

Expiration: Breathing out.

Explosion Class 1:  Flammable gas/vapor.

Explosion Class 2:  Combustible dust.

Explosion Class 3:  Ignitable fibers.

Explosion Proof:  An electrical apparatus so designed that an explosion of flammable gas or vapor inside the enclosure will not ignite flammable gas or vapor outside.

Explosion Level:  The level or concentration of a physical or chemical hazard to which an employee is exposed.

Explosive: A substance that causes a sudden, almost instantaneous release of pressure, gas, and heat when subjected to sudden shock, pressure, or high temperature.

Explosive Atmosphere:  An atmosphere where the concentration of contaminants is between the lower and upper explosive limits, as defined by the authority having jurisdiction.

Exposed Aggregate: A method of finishing concrete which washes the cement/sand mixture of the top layer of the aggregate – usually gravel. Often used in driveways, patios and other exterior surfaces.

Exposed Aggregate Finish: A method of finishing concrete which washes the cement/sand mixture off the top layer of the aggregate – usually gravel. Often used in driveways, patios and other exterior surfaces.

Exposed Nail Method: Application of roll roofing in which all nails are driven into the cemented, overlapping course of roofing. Nails are exposed to the weather.

Exposure I Grade Plywood: Type of plywood approved by the American Plywood Association for exterior use.

Exposure:   An event in which an organism comes in contact with a chemical or biological agent.
 
Exposure Assessment:   Measurement or estimation of the magnitude, frequency, duration, and route of exposure of humans, animals, materials, or ecological components to substances in the environment. The assessment also describes the size and nature of the exposed population.

Exposure Limits:  Accepted standard values that are formulated to ensure that human exposure to a contaminant does not result in adverse health effects; they are expressed in various units; see Threshold Limit Value.

Exposure Pathways:  Existing or hypothetical routes by which chemicals in soil, water or other media can come in contact with humans, animals or plants.

Exsanguination:  Generally, the excessive loss of blood. As a secondary technique for euthanasia, it may involve deliberately removing as much blood as possible from an animal.

Exterior Glazed: Glazing infills set from the exterior of the building.

Exterior Stop: The molding or bead that holds the light or panel in place when it is on the exterior side of the light or panel.

External Dose or Exposure:  That portion of the dose equivalent received from radiation sources outside the human body.

External Drive:  A term used to indicate a compressor driven directly from the shaft or by a belt using an external motor.

Extinction Coefficient:  A property of glazing material that characterizes the solar absorption in the material, namely, the fraction of radiation that is absorbed per unit of path length through the material.

Extractables:  Chemicals leached from a filter during a filtration process; usually tested for by soaking in water under controlled conditions; may be removed by pre-flushing with suitable liquid.

Extraction Wells:  Wells that are used primarily to remove contaminated groundwater from the ground. Water level measurements and water samples can also be collected from extraction wells.

Extras: Additional work requested of a contractor, not included in the original plan, which will be billed separately and will not alter the original contract amount, but increase the cost of building the home.

Extrinsic Asthma: Asthma triggered by an allergic reaction, usually something that is inhaled, or in the environment.

Extrusion: An item formed by forcing a base metal (frequently aluminum) or plastic, at a malleable temperature, through a die to achieve a desired shape.

Eye Hazards:  Any number of things that can harm an eye including: foreign objects, dust, sparks, chemical liquid and fumes, and harmful rays.  May also include tasks or conditions that create eye strain or impair effective vision (excessive VDT use in poor conditions, glare, poor lighting, etc.).

Eyebrow: A flat, normally concrete, projection which protrudes horizontally from a building wall; Eyebrows are generally located above windows.

Eyewash: A device used to irrigate and flush the eyes.