WAC 51-13-202   Definitions.


       Addition: An extension or increase in floor area or height of a building or structure.


     Aggregate: Crushed stone, stone, or other inert material, or combinations thereof having hard, strong, durable pieces.


     Air barrier: A continuous material or system of materials utilized for the purpose of minimizing the movement of air across a defined boundary, and capable of withstanding the maximum pressure developed across it, without failing by becoming significantly more leaky.


     Air, exhaust: Air removed from a space and not reused therein.


     Air, outdoor: Air taken from the external atmosphere and, therefore, not previously circulated through the HVAC system or the conditioned space.


     Air, supply: That air delivered to the conditioned space and used for ventilation, heating, cooling, humidification, or dehumidification.


     Air, transfer: The movement of indoor air from one space to another.


     Air, ventilation: That portion of supply air that is outdoor air plus any recirculated air that has been treated for the purpose of maintaining acceptable indoor air quality.


     AMCA: Air Movement and Control Association, Inc.


     Approved: As to material and types of construction, refers to approved by the building official as the result of investigation and tests conducted by him, or by reason of accepted principles or tests by recognized authorities, technical or scientific organizations.


     ASHRAE: American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc.


     Automatic: Self-acting, operating by its own mechanism when actuated by some impersonal influence, as for example, a change in current strength, pressure, temperature, or mechanical configuration.


     Back-draft damper: A damper installed to restrict introduction of unconditioned air from an unconditioned space to a conditioned space.


     Barometric damper: Shall be any listed nonmanual device that freely allows the flow of air in one direction, but does not allow conditioned air to escape. Any installed combustion air damper shall meet the installation requirements of the manufacturer.


     Building official: The officer or other designated authority charged with the administration and enforcement of this Code, or his duly authorized representative.


     Certified local government: The local government has been certified by the state historical preservation officer as having established its own historic preservation commission and a program meeting federal and state standards.


     CFM: Cubic feet per minute.


     Conditioned floor area: The floor area within the conditioned space.


     Conditioned space: That part of a building that is heated or cooled or both for the comfort of occupants.


     Dehumidistat: An automatic control device which measures changes in humidity and controls a device(s) for maintaining a maximum specified humidity range or level.


     Exfiltration: The uncontrolled outward air leakage through cracks and concealed spaces in any building element and around sole plates, wall outlets, duct systems, windows, and doors of a building, caused by the pressure effect of wind and/or the effect of differences in the indoor and outdoor air density.


     Gravel: A type of aggregate.


     Habitable space (room): Space in a structure for living, sleeping, eating, or cooking. Bathrooms, toilet compartments, closets, halls, storage, or utility space and similar areas, are not considered habitable space. For the purpose of this Code, a single habitable space may consist of adjoining rooms when one half of the area of the common wall is open and unobstructed and provides an opening of not less than one-tenth of the floor area of the interior room or twenty five square feet, whichever is greater.


     Heat 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 airstream.


     Historic buildings: Any structure, collection of structures, and their associated sites, deemed of importance to the history, architecture, or culture of an area by an appropriate local, state, or federal government jurisdiction. This includes structures on official national, state, or local listings such as the National Register of Historic Places, the State Register of Historic Places, state points of historical interest, and registers or listings of historical or architecturally significant sites, places, historic districts, or landmarks as adopted by a certified local government.


     Humidistat: An automatic control device which measures changes in humidity and controls a device(s) for maintaining a minimum specified humidity range or level.


     HVAC: Heating, ventilating, and air conditioning.


     HVI: Home Ventilating Institute of America, Inc.


     Infiltration: The uncontrolled inward air leakage through cracks and concealed spaces in any building element and around sole plates, wall outlets, duct systems, windows, and doors of a building, caused by the pressure effect of wind and/or the effect of differences in the indoor and outdoor air density.


     "J" Definitions: (Reserved)


     "K" Definitions: (Reserved)


     "L" Definitions: (Reserved)


     Manual: Capable of being operated by human intervention.


     Masonry heater: A heating system which is predominantly masonry construction, having a mass of at least 1764 pounds (800 kg) excluding chimney and base. Within the masonry mass are contained a firebox and multiple heat exchange channels which store the heat and allow for extremely high temperature fires to be burned.


     Mitigate: To design, select, apply, and install systems, materials, and processes that reduce radon concentrations in the indoor air of a building, and/or prevent entry of radon into the indoor air of a building, so that the average indoor radon concentration is reduced to an acceptable level.


     New construction: Any building, addition or change in occupancy permitted on or after the effective date of this Code.


     "O" Definitions: (Reserved)


     Picocurie, pCi: A measure of radioactive activity equal to one trillion of a curie. A curie is the amount of any radionuclide that undergoes thirty seven billion nuclear disintegrations per second, hence a picocurie is .037 nuclear disintegrations per second.


     Picocurie per liter, pCi/L: A common unit of measurement of the concentration of radioactivity in a gas. One pCi/L corresponds to 2.22 radioactive disintegrations per minute per liter of air.


     "Q" Definitions: (Reserved)


     R value: (See Thermal resistance (R))


     Readily accessible: Readily accessible means capable of being reached safely and quickly for operation, repair, or inspections, without requiring those to whom ready access is requisite to climb over or remove obstacles, or to resort to the use of portable access equipment.


     Soil depressurization system (SDS): A radon control technique that depressurizes the space below a concrete slab or other soil gas retarder relative to the space above it. The purpose of SDS is to maintain a slightly lower pressure in the soil gas under the slab or other soil gas retarder, compared to the indoor pressure above it, to ensure that flows are from the indoors to the soil, thus preventing mass transport of radon contaminated soil gas to the indoor air.


     Soil gas retarder membrane: A flexible sheet material placed between the soil and the indoor air for the purpose of reducing the flow of soil gas into the building.


     Solid fuel burning appliance: Any factory-built appliance designed to burn solid fuels.


     Source specific ventilation system: A mechanical ventilation system including all fans, controls, and ducting, which is dedicated to exhausting contaminant-laden air to the exterior of the building from the room or space in which the contaminant is generated.


     System: A combination of equipment and/or controls, accessories, interconnecting means, and terminal elements by which air is transferred.


     Terminal element: The means by which the transferred air from a system is finally delivered; i.e., registers, diffusers, through-the-wall vents, roof caps, etc.


     Thermal resistance (R): The resistance of a material to heat flow, measured as the inverse of heat flow per unit area, per unit time, per unit temperature difference across the thickness of material considered. In this Code, R has units of sq.ft./hr.°F/Btu.


     Thermostat: An instrument which measures changes in temperature and control device(s) for maintaining a desired temperature.


     Unconditioned space: (See Conditioned space)


     Ventilation: The process of supplying and removing air by natural or mechanical means to and from any space. Such air may or may not be conditioned.


     Ventilation, mechanical: The introduction and distribution of outdoor air and the removal of indoor air by mechanical means.


     Ventilation, natural: Ventilation other than by mechanical means.


     Virgin polyethylene: Extruded polyethylene sheets made from nonreprocessed resins.


     Whole house ventilation system: A mechanical ventilation system, including fans, controls, and ducts, which replaces, by direct or indirect means, air from the habitable rooms with outdoor air.


     Wood stove: (See Solid fuel burning appliance)


     "X" Definitions: (Reserved)


     "Y" Definitions: (Reserved)


     Zone: A space or group of spaces within a building with heating and/or cooling requirements sufficiently similar so that comfort conditions can be maintained throughout by a single controlling device.



[Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-202, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-202, filed 12/18/90, effective 7/1/91.]