- DaylightingThe efficient use of natural light in ways that minimize the need for artificial light in buildings. It is achieved by control strategies and adapted components which fall mainly into three categories: • conduction components - spaces used to guide or distribute light towards the interior of a(...)
- DehumidificationRemoval of water vapor from air. Source: from Gatley, Understanding Psychrometrics. Related Resources: RR-0215: Dehumidification Systems Research Results; RR-1008: Building America Special Research Project—Enhanced Dehumidification
- Dense Pack InsulationA method of insulation application that results in insulation that is less prone to air filtration and settling. Source: www.buildingscience.com.
- Dew PointThe temperature at which the relative humidity of a sample of air with constant water vapor reaches 100%. The air is saturated with water when it reaches the dew point and condensation will occur on a surface. Source: BSI-049: Confusion About Diffusion; RR-0203: Relative Humidity
- DiffusionThe movement of individual molecules through a material. The movement occurs because of concentration gradients and (to a much lesser degree) thermal gradients, independent of airflow. A mode of water vapor transport in building enclosures that is much slower than airflow. Source: BSI 049:(...)
- Drainage PlaneDrainage planes are water repellent materials (building paper, housewrap, foam insulation, etc.) which are designed and constructed to drain water. They are interconnected with flashings, window and door openings, and other penetrations of the building enclosure to provide drainage of water to(...)
- DrainedA building enclosure rain control strategy (or ground water control) that accepts that some water will penetrate the outer surface (the cladding, which “screens” rain) and removes this water back to the exterior by gravity drainage over a drainage plane, through a drainage gap, and exiting via(...)
- DurabilityThe capability of a building, assembly, component, or product to maintain serviceability over a specified time. Source: BSD 144: Increasing the Durability of Building Constructions; RR-1207: Vancouver Field Exposure Facility—Phase III Exterior Insulation Analysis