ASHRAE-90.1-2022- - Page 028
Extracted Content
roof: the upper portion of the building envelope, including opaque areas and fenestration, that is horizontal or tilted at an angle of less than 60 degrees from horizontal. For the purposes of determining building enve- lope requirements, the classifications are defined as follows:
attic and other roofs: all other roofs, including roofs with insulation entirely below (inside of) the roof structure (i.e., attics, cathedral ceilings, and single-rafter ceilings), roofs with insulation both above and below the roof structure, and roofs without insulation but excluding metal building roofs . metal building roof: a roof that
a. is constructed with a metal, structural, weathering surface; b. has no ventilated cavity; and c. has the insulation entirely below deck (i.e., does not include composite concrete and metal deck
construction nor a roof framing system that is separated from the superstructure by a wood substrate) and whose structure consists of one or more of the following configurations:
- Metal roofing in direct contact with the steel framing members
- Metal roofing separated from the steel framing members by insulation
- Insulated metal roofing panels installed as described in subitems (a) or (b) roof with insulation entirely above deck: a roof with all insulation
a. installed above (outside of) the roof structure and b. continuous (i.e., uninterrupted by framing members). single-rafter roof: a subcategory of attic roofs where the roof above and the ceiling below are both attached to the same wood rafter and where insulation is located in the space between these wood rafters.
roof area, gross: the area of the roof measured from the exterior faces of walls or from the centerline of party walls . (See roof and wall .)
roof covering: the topmost component of the roof assembly intended for weather resistance, fire classification, or appearance.
roof monitor: that part of a building that projects above the plane of the roof and whose walls contain verti- cal fenestration for lighting the interior.
roof recovering: the process of installing an additional roof covering over an existing roof covering without removing the existing roof covering .
roof replacement: an alteration that includes the removal of all existing layers of the roof assembly materials down to the roof deck and installing a new roof assembly above the roof deck.
room air conditioner: an encased assembly designed as a unit to be mounted in a window or through a wall or as a console. It is designed primarily to provide direct delivery of conditioned air to an enclosed space, room, or zone. It includes a prime source of refrigeration for cooling and dehumidification and a means for circulating and cleaning air. It may also include a means for ventilating and heating.
room cavity ratio (RCR): a factor that characterizes room configuration as a ratio between the walls and ceiling and is based on room dimensions.
saturated condensing temperature: the saturation temperature corresponding to the measured refrigerant pressure at the condenser inlet for single component and azeotropic refrigerants, and the arithmetic average of the refrigerant dew-point temperature and the bubble-point temperature corresponding to the refrigerant pressure at the condenser entrance for zeotropic refrigerants.
seal class A: a ductwork sealing category that requires sealing all transverse joints, longitudinal seams, and duct wall penetrations. Duct wall penetrations are openings made by pipes, holes, conduit, tie rods, or wires. Longitudinal seams are joints oriented in the direction of airflow. Transverse joints are connections of two duct sections oriented perpendicular to airflow.
seasonal energy efficiency ratio (SEER): the total cooling output of an air conditioner during its normal annual usage period for cooling (Btu) divided by the total electric energy input during the same period (W). ( Informative Note: SEER2 reflects the new higher static effective 1/1/2023.)
secondary sidelighted area: see daylight area.
sectional garage door: see door .
semiexterior building envelope: see building envelope .
semiexterior wall: see building envelope and wall .
26 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)