BOC Energy Conservation Techniques 2

Question 1

An operator notices the building's HVAC runs at full occupancy settings on weekends when the building is empty. What is the most cost-effective first step?

Accepted Answer

Program setback/setup schedules in the BAS for unoccupied periods

Answer

Scheduling setback and setup temperatures during unoccupied hours is a no-cost or low-cost measure that cuts runtime substantially.

Question 2

According to the fan affinity laws, reducing fan speed by 20% reduces fan power consumption by approximately how much?

Accepted Answer

49%

Answer

Power varies with the cube of speed, so 0.8³ ≈ 0.51, which is roughly a 49% reduction.

Question 3

Which economizer control strategy uses both outdoor air temperature and humidity to decide when to use free cooling?

Accepted Answer

Enthalpy-based

Answer

Enthalpy economizers compare total heat content (temperature plus moisture), which avoids bringing in humid air that only looks cool.

Question 4

A demand-controlled ventilation (DCV) system typically adjusts outdoor air intake based on which measurement?

Accepted Answer

Space CO2 concentration

Answer

DCV uses CO2 levels as a proxy for occupancy and lowers ventilation when fewer people are present.

Question 5

What is the main energy benefit of resetting chilled water supply temperature upward during mild weather?

Accepted Answer

It improves chiller efficiency by reducing compressor lift

Answer

A higher chilled water setpoint reduces the pressure difference the compressor must overcome, which lowers kW per ton.

BOC - Building Operator Certification Practice Test

BOC - Building Operator Certification Practice Test

BOC Energy Conservation Techniques 2