Energy Efficiency & Conservation Techniques Flashcards

What does the term 'building envelope' refer to in energy efficiency?

Answer: The physical barrier between conditioned and unconditioned spaces

The building envelope includes walls, roofs, floors, windows, and doors that separate interior conditioned space from the exterior environment.

Which insulation metric indicates resistance to heat flow per unit area?

Answer: R-value

R-value measures thermal resistance; higher R-values indicate better insulating performance and reduced heat transfer.

A blower door test is used primarily to measure:

Answer: Overall building air infiltration rate

A blower door depressurizes the building and measures how much air leaks in, quantifying overall envelope airtightness.

In climate zones with hot summers and mild winters, which strategy provides the greatest cooling energy savings?

Answer: Increasing roof reflectance with a cool roof

Cool roofs with high solar reflectance reduce heat gain through the roof, directly lowering cooling loads in hot climates.

The Energy Use Intensity (EUI) of a building is expressed as:

Answer: BTU per square foot per year

EUI normalizes a building's total energy consumption by its floor area, typically expressed as kBtu per square foot per year.

Which load type is reduced most directly by installing occupancy sensors in commercial spaces?

Answer: Lighting load

Occupancy sensors automatically turn off lights when spaces are unoccupied, directly reducing the lighting electrical load.

Thermal mass in a passive solar building functions by:

Answer: Absorbing and slowly releasing heat to moderate temperature swings

High-density materials like concrete and masonry absorb solar heat during the day and release it slowly at night, stabilizing indoor temperatures.