|
|
Glossary |
|
Air Changes Per Hour (ACH): An expression of ventilation rates - the number of times per hour that a building’s entire volume of air is exchanged with outside air. Air Barrier: A layer of material resistant to air flow usually in the form of polyolefin (i.e. Typar, Tyvek, and other house wraps). 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: The assembly of components used in building construction to create a plane of air tightness throughout the building envelope and to control air leakage. American Made: Manufactured in The United States. Blower Door Diagnostic: Equipment consisting of a fan, removable panel and gauges, used to measure and locate air leaks. Blowing Agent: A gas or a substance capable of producing a gas used in making foamed materials. Btu: British Thermal Unit - the amount of energy that is required to raise 1 lb. of water up 1° F Btu/h: A rate of energy transfer - can be expressed as Btu’s/hour Building Envelope: The external elements walls, floor, ceiling, roof, windows and doors of a building that encloses conditioned space; the building shell. Capillary Action: The movement of liquid within a material against gravity as a result of surface tension. 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 fuels 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. Density: Determined by the weight expressed in pounds per 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. Exfiltration: Uncontrolled leakage of conditioned air from inside the home to the outside. Flame Retardant: A substance, which is added to a polymer formulation to reduce or retard the tendency to burn. Flame Retarded (Adj.): 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. 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. Humidistat: A humidity sensitive control device that signals the ventilation system to operate if the humidity goes above a preset limit. Hydrophobic: Having no affinity for water; not compatible with water. "Water fearing" 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. Isocyanurate (MDI): One of a group of neutral derivatives of primary amines (R-N=C=O) groups. An essential component (A) of spray foam chemistry. Kilowatt-hour (kWh): Standard unit for measuring Electrical: Energy consumption-kilowatts X hours. Material Safety Data Sheet (MSDS): A 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. Organic: Compounds containing carbon. Overspray: (1) Airborne spray loss of polyurethane foam. (2) Undesirable depositions of airborne spray loss. Perm: A unit of water vapor transmission defined as 1 grain of water vapor per square foot per hour per inch of mercury pressure difference (1 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: A 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. 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. R: A unit of measurement of resistance to heat flow in hr. ft2 ° F/BTU.in. RSI: A unit of measurement of resistance to heat flow in m2 ° C/W per 25 mm. R = 0.176 RSI Resin: Component B in spray foam chemistry. This component is mixed with the A component to form ZipFoam. Retrofit: The modification of an existing building or facility to include new systems or components. Standard Testing: Laboratory test methodology for determining relative properties of materials at specific conditions. Thermostat: Temperature sensitive control device that signals a heating or cooling system to operate if the temperature in the building reaches a preset limit. Thermal Barrier: A material applied over ZipFoam designed to slow the temperature rise of the foam during a fire situation and delay its involvement in the fire. Thermal Bridge: A thermally conductive material which penetrates or bypasses an insulation system; such as a metal fastener or stud. Thermal Resistance (R): An index of a material's resistance to heat flow. See R and RSI. Thermal Shock: A building materials 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. 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). Vapor Retarder/Barrier: A layer of moisture resistant material usually which controls moisture diffusion (defined as less than 1 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 Compound (VOC): Any compound containing carbon and hydrogen or containing carbon and hydrogen in combination with other elements. ACRONYMS AISI:
American Iron & Steel Institute |