Building Envelope and Insulation Flashcards

Earth coupling (ground-source) benefits in building design come from:

Answer: The relatively constant ground temperature moderating both heating and cooling loads

Ground temperature at depth remains near the annual mean air temperature, providing a moderate heat sink in summer and heat source in winter for ground-coupled systems.

The purpose of a thermal break in a curtain wall system is to:

Answer: Interrupt the conductive metal path to reduce heat transfer through the frame

Thermal breaks are non-conductive insulating material inserted into aluminum frames to interrupt the metal conduction path and significantly reduce frame U-factor.

Low-e (low-emissivity) coatings on window glazing primarily reduce heat transfer by:

Answer: Reflecting long-wave infrared radiation to reduce radiative heat exchange

Low-e coatings have high reflectance for long-wave infrared (thermal radiation), keeping room heat inside in winter and blocking radiant heat gain in summer.

Weatherstripping around doors and windows is an energy conservation measure because it:

Answer: Reduces air infiltration and exfiltration at openings

Weatherstripping seals gaps at operable joints, directly reducing air leakage that would otherwise force HVAC systems to condition infiltrating outside air.

A building energy simulation model uses envelope data primarily to calculate:

Answer: Hourly heating and cooling loads driven by conduction, infiltration, and solar gains

Envelope properties — insulation levels, glazing U-factor and SHGC, infiltration rates — directly determine conduction and solar-driven loads calculated in hourly energy simulations.

The primary purpose of a vestibule (airlock entry) in a commercial building is to:

Answer: Reduce infiltration by preventing direct outdoor air connection when doors open

Vestibules with two sets of doors ensure that at least one door is closed at all times, dramatically reducing infiltration from door opening cycles especially in cold climates.