Building Energy Efficiency and Sustainability Flashcards

Which ASHRAE standard defines the procedures for Level 1, Level 2, and Level 3 commercial building energy audits?

Answer: ASHRAE Standard 211

Standard 211 sets the requirements for commercial building energy audits at Levels 1, 2, and 3.

A centrifugal supply fan on a VFD drops to 50% speed. Using the fan affinity laws, about how much of its full-speed power does it draw?

Answer: 12.5%

Fan power varies with the cube of speed, so (0.5)^3 = 0.125, or about 12.5% of full power.

In the ASHRAE 90.1 Appendix G Performance Rating Method, which metric is compared against a target to show compliance?

Answer: Performance Cost Index (PCI)

Appendix G compliance compares the proposed design's Performance Cost Index with the required PCI target.

What is the main difference between an energy recovery ventilator (ERV) and a heat recovery ventilator (HRV)?

Answer: An ERV transfers both sensible and latent energy, while an HRV transfers mainly sensible heat

ERV cores such as enthalpy wheels move moisture as well as heat, while HRVs recover mostly sensible heat.

Under the ASHRAE 90.1 prescriptive envelope path, what is the maximum vertical fenestration area as a percentage of gross above-grade wall area?

Answer: 40%

The prescriptive path limits vertical fenestration to 40% of gross above-grade wall area, and designs with more glazing must use a performance path.

Which IPMVP option determines savings from whole-facility utility meter data?

Answer: Option C

IPMVP Option C uses whole-facility meter or utility bill data to measure savings.

What minimum ENERGY STAR score does a building need to qualify for ENERGY STAR certification?

Answer: 75

A building must score 75 or higher, meaning it performs better than at least 75% of similar buildings nationwide.