Energy Efficiency & Conservation Techniques Flashcards
7 cards from real NABCEP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Energy Efficiency & Conservation Techniques flashcards as text
Which lighting efficiency metric describes the amount of visible light produced per watt of electrical power consumed?
Answer: Lumens per watt (efficacy)
Luminous efficacy (lumens per watt) is the standard measure of how efficiently a light source converts electrical energy into visible light.
Earth tube (ground-coupled heat exchanger) systems pre-condition incoming ventilation air by:
Answer: Exchanging heat with the relatively stable ground temperature
Buried tubes allow incoming air to exchange heat with stable ground temperatures (55–65°F), pre-warming air in winter and pre-cooling it in summer.
A heat recovery ventilator (HRV) differs from an energy recovery ventilator (ERV) primarily because an HRV:
Answer: Transfers heat only without moving moisture
An HRV transfers sensible heat only, while an ERV additionally transfers latent energy (moisture), making ERVs better suited for humid climates.
In the context of energy-efficient building design, what does 'thermal bridging' refer to?
Answer: A conductive path through insulation that bypasses its thermal resistance
Thermal bridges are high-conductivity elements (like metal studs or concrete columns) that allow heat to bypass insulation, reducing overall envelope performance.
Which metric is most appropriate for comparing annual energy costs of different heating fuel types?
Answer: Cost per million BTU (MMBtu) of useful heat delivered
Cost per MMBtu of useful heat accounts for both fuel price and equipment efficiency, enabling a true apples-to-apples comparison across fuel types.
Retrocommissioning (RCx) of an existing building is best described as:
Answer: Systematically investigating and correcting operational deficiencies to restore designed performance
Retrocommissioning optimizes existing systems by identifying control faults, scheduling errors, and maintenance issues without major equipment replacement.
Which measure would most effectively reduce baseload electricity consumption in a commercial building operating 24/7?
Answer: Replacing server room equipment with more efficient models and improving IT cooling
Server rooms and IT loads run continuously; improving equipment efficiency and precision cooling directly cuts 24/7 baseload consumption.