Energy Management and Control Systems Flashcards
6 cards from real CEM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Energy Management and Control Systems flashcards as text
A Building Automation System (BAS) primarily serves to:
Answer: Monitor and control building mechanical, electrical, and HVAC systems from a central platform
A BAS integrates sensors, controllers, and actuators across HVAC, lighting, and other building systems into a centralized platform for monitoring, control, and optimization.
An Optimal Start control strategy in a BAS saves energy by:
Answer: Starting HVAC just early enough to reach setpoint by occupancy time, minimizing pre-conditioning time
Optimal Start calculates the minimum pre-conditioning time needed based on outdoor conditions and thermal mass, avoiding unnecessary hours of HVAC operation before occupants arrive.
Demand-controlled ventilation (DCV) uses CO2 sensors to:
Answer: Modulate outdoor air supply in proportion to actual occupancy detected by CO2 concentration
DCV modulates outdoor air dampers based on indoor CO2 levels as a proxy for occupancy, providing required ventilation only when and where needed, reducing HVAC conditioning loads.
Setback temperature control in an unoccupied building saves energy by:
Answer: Allowing indoor temperature to drift toward outdoor conditions during unoccupied periods
During unoccupied hours, setback allows temperatures to rise in summer or fall in winter within an acceptable range, reducing the temperature differential driving heat transfer and lowering HVAC energy use.
Which communication protocol is commonly used in modern BAS for interoperability between different manufacturers' equipment?
Answer: BACnet (Building Automation and Control Network)
BACnet is an ASHRAE/ISO/ANSI standard protocol designed specifically for building automation, enabling interoperability between devices from different manufacturers.
Fault Detection and Diagnostics (FDD) in a BAS is used to:
Answer: Automatically identify equipment faults and inefficiencies before they cause failures or energy waste
FDD uses rule-based or machine-learning algorithms to analyze sensor data and identify equipment faults, control errors, and efficiency degradation, enabling proactive maintenance.