Glossary
A
A-Scale. Filter system with characteristics that roughly match the response characteristics of the human ear at low sound levels (generally below 55 dB but often used to gauge levels to 85 dB)
Abatement. To reduce or make void any substance such as the removal of noise, asbestos or lead. See asbestos abatement definition as one form of removal.
Abrasion resistance. The ability of a material to withstand abrasion without appreciative erosion.
Absorptance. The ratio of the radiant flux absorbed by a body to that incident upon it.
Absorption. Process of drawing fluid or gas into a porous material, such as a sponge soaking up water.
Absorption transformation. Absorption transformation of radiant energy to a different form of energy by interaction with matter.
Abuse coverings and finishes. Jackets, mastics or strong films used to protect insulation from mechanical and personnel abuse.
Acoustical treatment. Application of absorbing insulation for sound control.
Adsorption. Refers to the surface retention or adhesion of a very thin layer of water molecules to the surfaces of a material (such as insulation fibers) with which they are in contact. Also see Sorption.
Aerogel. Homogeneous, low-density solid state material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The resulting material has a porous structure with an average pore size below the mean free path of air molecules at standard atmospheric pressure and temperature.
Air Barrier. Meets ASTM E283 A layer of material resistant to air flow usually in the form of polyolefin (i.e. Typar, Tyvek, and other housewraps). A material which is applied in conjunction with a building component (such as a wall, ceiling or sill plate) to prevent the movement of air through that component.
Air Barrier System. Assembly of components used in building construction to create a plane of air tightness throughout the building envelope and to control air leakage.
Air Changes per Hour (ACH). Expression of ventilation rates; the number of times per hour that a home’s entire air volume is exchanged with outside air.
Air-conditioned space. Building area supplied with cooled conditioned air.
AISI. American Iron & Steel Institute
ALA. American Lung Association
Alkalinity. Quality of a material to be basic or alkaline when exposed to moisture or water producing a blue reaction to litmus paper. A pH measure greater than 7.0.
Ambient. Surrounding or encompassing; generally applied to temperature, humidity and atmospheric conditions. The average temperature of the medium, usually air, surrounding the object under consideration.
ANSI. American National Standards Institute
Apparent Thermal Conductivity. Value assigned to a material that exhibits thermal transmission by several modes of heat transfer resulting in property variation with specimen thickness or surface emittance. Approximately, it equals the ratio of the partial pressure or density of the water vapor in. The air to the saturation pressure or density, respectively, at the same temperature.
Apparent Thermal Resistivity. Thermal resistivity assigned to a material that exhibits thermal transmission by three modes of heat transfer resulting in property variation with specimen thickness, or surface emittance. (See resistivity, thermal, R-value).
ASE. Alliance to Save Energy
ASHRAE. American Society of Heating, Refrigerating and Air-Conditioning Engineers.
ASJ. All service jacket; a laminate facing or covering constructed with. A white kraft paper, fiberglass scrim and a thin aluminum foil.
ASTM. American Society for Testing and Materials. An independent non-profit organization that has accepted responsibility for the development and administration of voluntary standards for the testing and evaluation of a wide range of products.
Attenuation. Limiting of sound propagation from one area to another.
B
Blower Door. Diagnostic equipment consisting of a calibrated fan, removable panel and gauges, used to measure and locate air leaks.
Blowing Agent. A gas or a substance capable of producing a refrigerant gas used in making foamed materials.
British Thermal Unit (Btu). Amount of energy required to raise one pound of water one degree Fahrenheit.
Btuh. Rate of energy transfer that can be expressed as Btu per hour.
Building Envelope. The external elements walls which includes, floor, ceiling, roof, windows and doors of a building that encloses conditioned space; the building shell.
C
Capillary Action. The movement of liquid within a material against gravity as a result of surface tension.
Castor oil. Castor oil is a vegetable oil obtained from the castor bean.
Chlorofluorocarbon (CFC). Any of various halocarbon compounds consisting of carbon, hydrogen, chlorine, and fluorine, once used widely as aerosol propellants and refrigerants. Chlorofluorocarbons are believed to cause depletion of the atmospheric ozone layer.
Combustion Efficiency. A measure of useful heat extracted from a fuel source by an operating heating appliance. For example, a furnace with a combustion efficiency of 60 percent converts 60 percent of the fuel’s energy content into useful heat. The rest is lost as exhaust gases.
Conduction. Transmission of energy (heat /sound) through a material or from one material to another by direct contact. Materials with low rates of conductive heat transfer make good insulation.
Convection. Transmission of energy (heat /sound) from one place to another by movement of a fluid such as air or water.
D
Density. Determined by the weight expressed in pounds of a cubic foot of spray foam.
Dew Point. The temperature at which a vapor begins to condense.
Diffusion. The movement of water vapor from regions of high relative humidity (RH) toward regions of lower RH driven by a higher to lower temperature differential.
E
ENERGY STAR®. ENERGY STAR® is a U.S. Environmental Protection Agency program that helps businesses and individuals, on a voluntary basis, save money and address climate impacts through measures that improve energy efficiency. The ENERGY STAR® program was established by the EPA in 1992, under the authority of the Clean Air Act.
Environmentally Preferable Product (EPP). Designation given to products that are in compliance with Section 01350 of the Material Specifications, adopted by California High Performance Schools (CHPS). Testing is done using test method California Department of Health Services Standard Practice for the Testing of VOC Emissions Sources Using Small Scale Environmental Chambers (CA/DHS/EHLB/ R-174) and incorporates the chamber testing portion of California Specification 01350 for schools and residential buildings.
Exfiltration. Uncontrolled leakage of conditioned air from inside the home to the outside.
F
Flame Retardant. A substance which is added to a polymer formulation to reduce or retard the tendency to burn. Adjective: flame retarded is the property of a material to which flame-retardant has been added.
Flame Spread. Standard test for determining relative combustibility. The flame spread of a tested material is rated relative to red oak (flame spread = 100).
Flammability. Relative ability of a material to support combustion as expressed by its flash point.
Flood Resistant Material. A flood [damage]-resistant material is defined by the NFIP as “any building product (material, component or system) capable of withstanding direct and prolonged contact with floodwaters without sustaining significant damage.” The term “prolonged contact” means at least 72 hours, and the term “significant damage” means any damage requiring more than cosmetic repair. “Cosmetic repair” includes cleaning, sanitizing, and resurfacing (e.g., sanding, repair of joints, repainting) of the material. The cost of cosmetic repair should also be less than the cost of replacement of affected materials and systems. In addition to these requirements, individual materials that are considered flood damage-resistant must not cause degradation of adjacent materials or the systems of which the material is a part.
Formaldehyde. A colorless pungent irritating carcinogen used chiefly in aqueous solutions as a disinfectant and preservative and in chemical synthesis.
G
Global Warming Potential (GWP). Measure of the potential of substances to heat up the atmosphere. All measures of GWP are given relative to Carbon dioxide, the most well-known gas with global warming potential, which has a GWP of 1. HFC 245fa is referred to by the Environmental Protection Agency as High Global Warming Potential gas. Used as a blowing agent by several foam insulation manufacturers, HFC 245fa has a global warming potential of 950, which means it has 950 times the global warming potential of carbon dioxide.
H
Heat Loss. Heat that is lost from a building through air leakage, conduction and radiation. To maintain a steady interior temperature, heat losses must be offset by a combination of heat gains and heat contributed by a heating system.
Heat Recovery Ventilation System. A mechanical ventilation system that recovers energy from exhausted indoor air and transfers it to incoming air. This system usually incorporates an air-to-air heat exchanger which transfers the heat from exhaust air to the incoming air or vice versa.
HFA Propellant. Usually refers to hydrofluoroalkane-134a, used in chlorofluorocarbon-free (CFC-free) aerosol delivery systems.
Humidistat. A humidity sensitive control device that signals the ventilation system to operate if the humidity goes above a preset limit
Hydrochlorofluorocarbons (HCFC). Compounds containing carbon, hydrogen, chlorine and fluorine. They have shorter atmospheric lifetimes than CFCs and deliver less reactive chlorine to the stratosphere, the region of Earth’s atmosphere containing the ozone layer.
Hydrofluorocarbon (HFC). HFCs have replaced ozone-depleting chlorofluorocarbons (CFCs) in many applications but are powerful greenhouse gases, with 100-year global warming potential of between 140 and 11,700.
I
Infiltration. Uncontrolled leakage of air into a building through cracks around doors, windows, electrical outlets and at structural joints.
Insulation. Materials with low thermal conductivity characteristics that are used to slow the transfer of heat.
Isocyanate (MDI (diphenyl methane diisocyanate)). One of a group of neutral derivatives of primary amines (R-N=C=O) groups. An essential component (A) of spray foam chemistry.
K
Kilowatt-hour (kWh). Standard unit for measuring electrical energy consumption-kilowatts per hour.
M
Material Safety Data Sheet (MSDS). Standard formatted information sheet prepared by a material manufacturer, describing the potential hazards, physical properties, and procedures for safe use of a material.
Mold. Fungal growths often resulting in deterioration of organic materials, especially under damp conditions.
Mycotoxin. Any poisonous substance produced by a fungus.
N
NFIP. National Flood Insurance Program.
O
Organic. Compounds containing carbon.
Overspray. (1) Airborne spray loss of polyurethane foam. (2) Undesirable depositions of airborne spray loss.
P
PBDE. Polybrominated diphenyl ethers or PBDE, are organic compounds that are used as a flame retardant in a wide array of products, including building materials such as polyurethane foam insulation. PBDEs have been linked to serious health problems such as birth defects, hormone deficiencies, learning disabilities and neurological disorders.
Perm. Unit of water vapor transmission defined as one grain of water vapor per square foot per hour per inch of mercury pressure difference (one inch mercury = 0.49 psi). Metric unit of measure is ng/m2 s Pa. 1 perm = 55 ng/m2 s Pa.
Permeability. The time rate of water vapor transmission through unit area of a material of unit thickness induced by unit vapor pressure difference between two specific surfaces, under specified temperature and humidity conditions.
pH. Measure of acidity/alkalinity of aqueous mixtures. A measure of pH 7 is neutral, lower is more acidic; higher is more alkaline.
PSI. Pounds per square inch, a measure of pressure.
R
R-value. Measure of thermal resistance used in the building construction industry. Ratio of the temperature difference across an insulator and the heat flow per unit area, Btu per hour per degree Fahrenheit per square foot.
Radiation. Transfer of energy (heat/sound) from one object to another through an intermediate space. Only the object receiving the radiation, not the space, is heated. The heat is in the form of low frequency, infrared, invisible, light energy, transferring from a warm object to a cold object. It is known as the black body effect.
Relative Humidity. The ratio expressed as a percentage of the amount of moisture air actually contains to the maximum amount it could contain at that temperature.
Resin. Component B in spray foam chemistry. This component is mixed with the A component to form a spray foam insulation.
Retrofit. The modification of an existing building or facility to include new systems or components.
RSI. A unit of measurement of resistance to heat flow in square meters.
S
Standard Testing. Laboratory test methodology for determining relative properties of materials at specific conditions.
T
Thermal Barrier. A material applied over Icynene
Thermal Bridge. A thermally conductive material like a wall framing stud, ceiling joist, or the top chord of a roof truss, that penetrates through an insulation barrier. A thermal bridge allows increased heat transfer that bypasses and reduces the effectiveness of an insulation barrier.
Thermal Resistance. See R-value. Index of a material’s resistance to heat flow.
Thermal Shock. A building material’s reaction to rapid changes in temperature.
Thermography. A building energy diagnostic technique using an infrared camera for locating areas of temperature differential in a building.
Thermostat. Temperature sensitive control device that signals a heating or cooling system to operate if the temperature in the building reaches a preset limit.
U
U-Value. Overall thermal conductance. U value is equal to the inverse of the sum of the R-values in a system (U = 1 /R total).
USDA BioPreferred℠ Program. Commercial or industrial products (other than food or feed) composed wholly or in significant part of biological products including renewable agricultural materials (plant, animal, and marine materials) or forestry materials. Under the USDA BioPreferred℠ Program, spray-in-place plastic foam products designed to provide a sealed thermal barrier for residential or commercial construction applications must meet a Minimum Biobased Content of seven percent.
V
Vapor Diffusion Retarder/Barrier. A layer of moisture-resistant material usually which controls moisture diffusion (defined as less than one perm) to prevent moisture build up in the walls.
Viscosity. The thickness or resistance to flow of a liquid. Viscosity generally decreases as temperature increases; application temperatures of spray foam components are specified in part, to control viscosity at the spray gun.
Volatile organic compounds (VOC). Any compound containing carbon and hydrogen or containing carbon and hydrogen in combination with other elements.