December 2016

TermDefinition
ACGIHAmerican Conference of Government Industrial Hygienists
AIHAAmerican Industrial Hygiene Association
Anchor BoltA bolt that is used to attach structures to concrete.
AOECAssociation of Occupational and Environmental Clinics
ASHRAEAmerican Society of Heating, Refrigeration and Air-Conditioning Engineers.
Awning WindowsA window with hinges at the top of the sash that swings outward.
Blown-in InsulationInsulation that is pumped or injected into walls, roofs, and other areas.
BOCABuilding Officials and Code Administrators
Building EnvelopeThe physical separator between the conditioned and unconditioned environment of a building which resists the air, water, heat, light, and noise from the outside from penetrating to the inside.
CantileverA long projecting beam or girder fixed at only one end, used for balconies.
Carpet BackingMaterial on the back of a carpet, usually made of  jute, cotton or rayon, sometimes with a latex coating.
Carpet PileThe visible surface of carpet, consisting of yarn tufts in loop and/or cut configuration.
Casement WindowA window that is hinged at the side.
CaulkingA waterproof filler and sealant, used in building work and repairs.
Ceiling PlenumSpace between the structural floor/roof deck and the suspended ceiling.
Cement BlockA concrete building unit with hollow space.
CFLCompact fluorescent light bulb.
ChillerA machine that cools the liquid used in cooling coils in an air conditioning system.
Chimney CapA device fitted to the top of a chimney to improve the draft by presenting an exit aperture to leeward and to prevent rainwater penetration down the chimney.
ClapboardA long, thin, flat piece of wood with edges horizontally overlapping in series, used to cover the outer walls of buildings.
CMRCode of Massachusetts Regulations
COCarbon monoxide, a product of incomplete combustion.
CO2Carbon dioxide, a product of metabolism, used as a measure of adequacy of ventilation.
CondensationWater that collects as droplets on a cold surface when humid air is in contact with it.
CondenserAn apparatus or container for condensing vapor.
Cooling coilEquipment that performs heat transfer to air when mounted inside an air handling unit or ductwork. It is cooled by circulating liquid.
Cornice TrimA decorative top edge of a building or column.
CovingA strip of molding, typically used for where the wall meets the floor.
CrawlspaceAn area of limited height under a floor or roof, giving access to wiring and plumbing.
DCAMMMassachusetts Division of Capital Assets Management and Maintenance
DCFMassachusetts Department of Children and Families
DDSMassachusetts Department of Developmental Services
Decay (Radioactive)Spontaneous disintegration of a radionuclide with the emission of energetic particles or radiation, such as alpha or beta particles or gamma rays.
DecibelsA unit of measure for sound.
Dew PointThe atmospheric temperature (varying according to pressure and humidity) below which water droplets begin to condense and dew can form.
DLSMassachusetts Department of Labor Standards
Door JambEach of the two upright parts of a doorframe, on one of which the door is hung.
DORMassachusetts Department of Revenue
DormerA window that projects vertically from a sloping roof.
Draeger tubeA device/system used to measure airborne chemicals.
Drain TrapA U-, S-, or J-shaped pipe located below or within a
Drainage PlaneA surface used in the design and construction of building enclosures to control rain.  Walls and the roof are part of the drainage plane.
Drip EdgeA metal flashing or other overhanging component with an outward projecting lower edge, intended to control the direction of rainwater.
Drip PanA container for catching material that drips from above, such as in an air handling unit to collect condensation.
Dust Spot EfficiencyThe ability of a filter to remove atmospheric dust from the air.
E.O.Executive Order
EfflorescenceA whitish, powdery deposit on the surface of brick and mortar. It is formed as mineral-rich water rises to the surface through capillary action and then evaporates.
EIFSExterior insulation foam system, a type of exterior building cladding/insulation.
Engineered WoodWood products which are manufactured by binding or fixing the strands, particles, fibers, or veneers or boards of wood, together with adhesives, or other methods of fixation to form composite materials, also called composite wood, man-made wood, or manufactured board.
EOHHSExecutive Office of Health and Human Services
Fascia BoardThe horizontal board which caps the end of rafters outside a building.
FenestrationWindows and doors of a building.
FiberglassFibrous glass used for insulation.
Flash PointThe lowest temperature of a volatile substance at which it can vaporize to form an ignitable mixture in air.
FlashingA strip of metal used to stop water from penetrating the junction of a roof, window, or doorframe with another surface.
Floor PlenumSpace between the structural floor/roof deck and an elevated floor space, typically found in computer mainframe rooms.
FlueA passage or duct for smoke in a chimney, often where the damper is located.
Foot-candlesA unit of illumination equal to that given by a source of one candela at a distance of one foot (equivalent to one lumen per square foot or 10.764 lux).
Foundation VentVent openings in a foundation wall that allow for
Four-way LouverA fresh air supply vent that directs air in four different directions.
FriableEasily crumbled or reduced to powder.
Frieze BoardA decorative band located on an outside wall or at the top of an interior wall.
Fume hoodA ventilated enclosure in a chemistry laboratory or vocational shop, in which harmful chemicals can be used.
GableThe part of a wall that encloses the end of a pitched roof.
Gable VentA vent located in the gable of a building.
Gambrel RoofA gable roof, each side of which has a shallower slope above a steeper one.
GhostingBlack streaking on walls and ceiling, typically from airflow patterns.
Glass Block WindowsA hollow, translucent, high-strength glass block used as a building material, chiefly for exterior and interior walls.
Gravity VentilationThe process of supplying air to and removing air from an indoor space without using mechanical systems (also called natural ventilation).
Gypsum WallboardWallboard with a gypsum plaster core bonded to layers of paper or fiberboard; used instead of plaster or wallboard to make interior walls.
Heat IndexA measure expressing the discomfort felt as a result of the combined effects of the temperature and humidity of the air.
HEPAHigh efficiency particle arrestance (or air), used to describe filters that must remove (from the air that passes through) 99.97% of particles that have a size of 0.3 µm.
Hip RoofA type of roof where all sides slope downwards to the walls, usually with a fairly gentle slope.
Homasote®A brand name associated with the product generically known as cellulose based fiber wall board, which is similar in composition to papier-mâché.
Hopper WindowsA window with hinges at the bottom of the sash that swings outward.
HUDU.S. Housing and Urban Development
I-beamA steel beam with an I- or H-shaped cross-section.
IICRCInstitute of Inspection, Cleaning and Restoration Certification
IPMIntegrated Pest Management
IsocyanateA chemical compound used in spray foam insulation.  It is also a known chemical sensitizer in exposed individuals.
Jalousie WindowsA window composed of parallel glass, acrylic, or wooden louvers set in a frame. The louvers are joined onto a track so that they may be tilted open and shut in unison to control airflow, usually by turning a crank.
JoistA length of timber or steel supporting part of the structure of a building, typically arranged in parallel series to support a floor or ceiling.
KerfA cut or incision made in a piece of wood.
KilnA furnace or oven for burning, baking, or drying, especially one for firing pottery.
Laminated Wood FlooringA multi-layer synthetic flooring product fused together with a lamination process. Laminate flooring simulates wood (or sometimes stone) with a photographic applique layer under a clear protective layer.
LathA thin flat strip of wood, especially one of a series forming a foundation for the plaster of a wall or the tiles of a roof.
LBOHLocal Board of Health
LouversHorizontal slats that are angled to admit light and air, but to keep out rain, direct sunshine, and noise; the angle of the slats may be adjustable.
LumensA unit of illumination (visible light) emitted by a source.
Mansard RoofA roof that has four sloping sides, each of which becomes steeper halfway down.
MasticA paste-like filler and sealant used in buildings.
MBIModular Building Institute
MDIMethylene diphenyl diisocyanate
MERV ratingMinimum efficiency reporting value, commonly known as MERV rating, is a measurement scale designed in 1987 by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to rate the effectiveness of air filters.
MGLMassachusetts General Laws
MicromanometerA device used to measure air pressure differentials.
MicronA unit of measure of length (diameter) of a particle.
Modular buildingA prefabricated building that comes in sections.
MortarA mixture of lime with cement, sand, and water, used in building to bond bricks or stones.
MortiseA hole or recess cut into a part, designed to receive a corresponding projection (a tenon) on another part so as to join or lock the parts together.
MSBAMassachusetts School Building Authority
ng/m3Nanograms per cubic meter; a nanogram is 10-9 grams.
NIHNational Institute of Health
NO2Nitrogen dioxide, a product of combustion associated with propane and a significant respiratory irritant.
OzoneA form of oxygen that consists of 3 oxygen atoms in one molecule.  It can be produced by arcing electricity, arc welding and other industrial and natural processes.  Ozone is a significant respiratory irritant.
Particle boardAn engineered wood product manufactured from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or other suitable binder, which is pressed and extruded.
Passive Air VentA grate, window, or undercut in a door or wall to allow natural airflow between rooms or between the inside and the outside.
PCBsPolychlorinated biphenyls, a hazardous material use as an insulating compound frequently found in caulking, light ballast and transformers.
pCi/LPicocurie per liter, a unit of measure of radiation associated with radon levels in buildings.
Perc (or PCE)Perchlorothylene
PilasterAn architectural structure used to give the appearance of a supporting column that is ornamental.
PlywoodAn engineered wood product that is type of strong thin wooden board consisting of two or more layers glued and pressed together with the direction of the grain alternating, and usually sold in sheets of four by eight feet.
PM2.5Particulate matter of a diameter of 2.5 microns of less.
PorousMaterials that can readily absorb water. Examples included gypsum wall board, carpeting, ceiling tiles, cardboard, paper upholstered furniture.
ppb (parts per billion)Used to report the mass of a chemical per unit volume of air.
ppm (parts per million)Used to report the mass of a chemical per unit volume of air.
Prestressed concreteConcrete in which reinforcing steel bars are stretched and anchored to compress it and thus increase its resistance to stress.
P-trapA drain trap in the shape of the letter “P” designed to have water remain in the pipe to provide a seal against sewer gas penetration.
R ValueA measurement of thermal resistance, the capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power.
RadonThe chemical element of atomic number 86, a rare radioactive gas belonging to the noble gas series.
RafterAn internal beam extending from the eaves to the peak of a roof and constituting its framework.
RebarA steel reinforcing rod in concrete.
RegisterAn adjustable plate for widening or narrowing an opening and regulating a draft.
Ridge VentA type of vent installed at the peak of a sloped roof which allows warm, humid air to escape a building's attic.
RMVMassachusetts Registry of Motor Vehicles
Sash WindowsWindows made of one or more movable panels that form a frame to hold panes of glass; the term is used almost exclusively to refer to windows where the glazed panels are opened by sliding (vertically or horizontally).
ScouringOccurs when soil is removed by force of water.
ScupperAn intentionally constructed hole in a parapet/edge of a building with a flat roof to allow water to exit the roof.
Sensitizer (chemical)A chemical that can cause allergic reactions after repeated exposure.
SIPSStructural Insulated Panels System
SMACNASheet Metal & Air Conditioning Contractors’ National  Association
Soffit VentA screened vent that allows air to flow into the attic or the space below the roof sheathing. Installed in concert with a ridge vent.
Soil StackThe pipe that takes all the wastewater from the plumbing system of a building.
Solar GainThe increase in temperature in a space, object or structure that results from direct sunlight.
SpackleA compound used to fill cracks in plaster and produce a smooth surface.
SpallingWhen stone or masonry breaks into smaller pieces as a result of weathering, corrosion or pressure.
SpandrelThe area between the sill of a window and the head of the window below it. In steel or reinforced concrete structures there will sometimes be a spandrel beam extending horizontally from one column to another and supporting a section of wall.
SphygmomanometerBlood pressure measure device that can contain mercury.
Spline CeilingA strip of metal or fiber inserted in the kerfs of adjacent acoustical tile to form a concealed mechanical joint seal.
Spray boothAn enclosure containing a flammable or combustible spraying operation and confining and limiting the escape of paint, vapor and residue by means of a powered exhaust system.
Spray Foam InsulationSpray foam insulation is a polyurethane foam used to insulate homes.  It is a two-component mixture composed of isocyanate and polyol resin.
S-trapA drain trap in the shape of the letter “S” designed to have water remain in the pipe to provide a seal against sewer gas penetration.
StringersThe structural members of a stairway that support the treads and risers.
TDIToluene diisocyanate
TenonA projecting piece of wood made for insertion into a mortise in another piece.
ThermohygrometerA device the measures temperature and humidity.
Tongue-in-groove FlooringA joint between two boards in which a raised area on the edge of one board fits into a corresponding groove in the edge of the other to produce a flush surface
Transfer AirAir transferred from one indoor area to another indoor area, usually via a passive air vent.
Transfer Air VentPassive air vent between one indoor area and another.
TrussA framework of rafters, posts, and struts used to support a roof or floor.
Turbine VentA ventilator, usually mounted on the roof of a building, having
Tyvek®A brand of material made of non-woven high-density polyethylene fibers; the name is a registered trademark of DuPont. It is often seen used as house wrap, a synthetic material used to protect buildings during construction and provide a drainage plane after buildings are completed.  It is pervious to water vapor but repels liquid water.
UFFIUrea formaldehyde foam insulation.
UniventA unit ventilator consists of a heating coil, fan assembly, dampers, filter and controls contained in a metal cabinet, usually located on the outside wall of a building.
VeneerA thin decorative covering of fine wood applied to a coarser wood or other material.
VOCVolatile organic compound, any volatile compound of carbon.
WaferboardAn engineered wood product that is a structural material made from rectangular wood flakes of controlled length and thickness bonded together with waterproof phenolic resin under extreme heat and pressure.
Wall StudA wall stud is a vertical framing member in a building's wall that is smaller in cross section than a post.
Weep HoleA small opening in an exterior wall that allows water to drain from within the wall assembly. Weepholes are located at the bottom of the object to allow for drainage.
μg/m3Micrograms per cubic meter, a measure of concentration of a chemical in air.  A microgram is 10-6 grams.

This information is provided by the Indoor Air Quality Program within the Department of Public Health.