Energy Management & Sustainability Flashcards

Under ASHRAE Standard 90.1, what does the standard primarily govern?

Answer: Energy efficiency requirements for commercial buildings

ASHRAE Standard 90.1 sets minimum energy efficiency requirements for commercial buildings, covering building envelope, HVAC, service water heating, power, and lighting.

What is 'submetering' in a multi-tenant building context?

Answer: Installing individual utility meters for each tenant to track their specific energy or water consumption

Submetering installs individual meters for each tenant space, enabling accurate billing based on actual consumption and motivating tenants to reduce their own energy use.

Which building envelope component has the greatest impact on reducing heating and cooling loads in most U.S. climates?

Answer: Roof and ceiling insulation

Roof and ceiling insulation reduces the largest surface area of heat transfer between conditioned and unconditioned space, making it typically the highest-impact envelope improvement.

A carbon footprint assessment for a building typically measures emissions in units of:

Answer: Metric tons of CO2 equivalent (MT CO2e)

Carbon footprint is measured in metric tons of CO2 equivalent (MT CO2e), which normalizes all greenhouse gases to their global warming potential relative to CO2.

What is the primary function of an economizer cycle in an HVAC system?

Answer: To use outside air for free cooling when outdoor conditions are favorable, reducing mechanical cooling energy

An economizer uses outdoor air directly for cooling when the outside temperature and humidity are suitable, bypassing mechanical refrigeration and saving significant energy.

Which water conservation strategy involves capturing and treating rainwater from rooftops for non-potable uses such as toilet flushing or irrigation?

Answer: Rainwater harvesting

Rainwater harvesting collects precipitation from rooftops, stores it in cisterns, and treats it for non-potable applications, reducing demand on municipal water supply.

When evaluating energy efficiency projects, the 'simple payback period' is calculated as:

Answer: Initial cost divided by annual energy cost savings

Simple payback period = initial investment ÷ annual savings, giving the number of years before accumulated savings recover the upfront cost of an energy project.