Glossary

AJAX progress indicator
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  • Christopher Alexander’s ground breaking book first published in 1977.  It is part 2 of a 3-part trilogy about the nature of the built environment.  A Pattern Language includes 253 universal patterns of human nature.   Selecting and organizing the relevant patterns to solve a design problem(...)
  • Process whereby a porous material extracts one or more substances from an atmosphere, a mixture of gases, or a mixture of liquids. Source: (from Gatley, Understanding Psychrometrics)
  • ACH is an acronym for Air Changes per Hour and is a measurement of air infiltration. It is the total volume of air in a home that is turned over in one hour. Source: http://www.energyauditingblog.com
  • (1) Process in which fluid molecules are concentrated on a surface by chemical or physical forces or both; (2) surface adherence of a material in extracting one or more substances present in an atmosphere or mixture of gases and liquids, unaccompanied by physical or chemical change. Source:(...)
  • A system of materials that enclose a volume of air with minimal air leakage between the enclosed air and the exterior. The effectiveness or adequacy of the air barrier can be measured by the volume of air (in cubic feet per minute) that must be added or removed from the enclosure to maintain a(...)
  • Uncontrolled inward leakage of air (that may contain entrained water vapor) through cracks and insterstices in any building element and around windows and doors of a building, caused by the pressure effects of wind or the effect of differences in the indoor and outdoor air density. Source:(...)
  • Uncontrolled and/or unintended airflow through a building enclosure or between units of occupancy. Leakage from indoors to outdoors is known as exfiltration and leakage from outdoors to indoors is known as infiltration. Air leakage can cause indoor air quality problems, condensation, excess(...)
  • A material or assembly that does not meet the performance requirements of an air control layer material or assembly, but that is nonetheless designed and constructed to control air flow. Source: The Passivhaus Handbook
  • Air Source Heat Pumps absorb heat from the outside air. This heat can then be used to heat radiators, underfloor heating systems, warm air convectors and hot water in your home. It extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can get heat(...)
  • The degree of leakage of air through the thermal envelope. (See air permeability and air changes per hour, above). Airtightness is a property of a building. Source: The Passivhaus Handbook
  • Arduino is an open-source prototyping platform based on easy-to-use hardware and software. Arduino boards are able to read inputs - light on a sensor, a finger on a button, or a Twitter message - and turn it into an output - activating a motor, turning on an LED, publishing something online.(...)
  • Naturally occurring fibrous minerals that because of their extreme durability and fire resistance were used extensively in residential and industrial construction. The inhalation of asbestos fibers can cause serious illnesses such as asbestosis, lung cancer and mesothelioma. Source:(...)
  • A building technology society with more than 50,000 members worldwide. ASHRAE’s activities include research, standards writing, publishing, and continuing education. Its areas of interest include building systems, energy efficiency, indoor air quality and sustainability within the(...)