Energy and Sustainability Professionals Flashcards

A commercial building's Lighting Power Density (LPD) is expressed in which units?

Answer: Watts per square foot (W/ft²)

LPD is the installed lighting power divided by the floor area, expressed in watts per square foot, and is the primary metric used in energy codes to regulate lighting efficiency.

What is the function of a demand-controlled ventilation (DCV) system in a commercial building?

Answer: Reduce outdoor air intake during periods of low occupancy based on CO2 sensing

DCV systems use CO2 sensors as a surrogate for occupancy to reduce outdoor airflow when spaces are partially occupied, saving both heating and cooling energy.

Under IECC 2021 commercial requirements, which of the following systems requires an economizer unless a specific exception applies?

Answer: HVAC units serving spaces greater than 54,000 Btu/h cooling capacity in most climate zones

IECC 2021 Section C403.5 requires air economizers on cooling equipment above approximately 54,000 Btu/h (4.5 tons) in most climate zones to utilize free cooling from outdoor air.

Which rating system is maintained by the U.S. Green Building Council and is commonly used alongside ICC codes for sustainable building certification?

Answer: LEED (Leadership in Energy and Environmental Design)

LEED, developed by the USGBC, is the most widely used green building rating system in the US and often complements IECC energy code compliance.

In the context of IECC residential blower door testing, what is the maximum allowable air changes per hour at 50 Pascals (ACH50) for Climate Zone 3?

Answer: 3 ACH50

IECC 2021 Table R402.4.1.2 sets a maximum of 3 ACH50 for Climate Zones 3 through 8 for homes verified by blower door testing.

A building energy auditor is classifying an audit according to ASHRAE Standard 211. A Level II audit differs from a Level I audit primarily because it includes:

Answer: Energy savings calculations with supporting engineering analysis for all identified measures

An ASHRAE 211 Level II audit extends beyond the Level I walkthrough to include engineering-based energy savings and cost calculations for each identified energy conservation measure.

What is the purpose of the 'Cool Roof' requirement found in IECC commercial provisions for low-slope roofs in hot climates?

Answer: To reduce cooling loads by reflecting solar radiation away from the building

Cool roof requirements mandate minimum solar reflectance and thermal emittance values for low-slope roofing materials to reduce heat gain and lower peak cooling energy use.