Certified Energy Auditor Certification HVAC Systems and Controls 2

Question 1

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

Accepted Answer

Use outdoor air for free cooling when conditions allow

Answer

An economizer uses outdoor air for cooling when outside conditions are favorable, reducing or eliminating mechanical cooling energy.

Question 2

A chiller's coefficient of performance (COP) is defined as:

Accepted Answer

Cooling output divided by electrical input

Answer

COP equals the useful cooling energy output divided by the electrical energy consumed by the chiller.

Question 3

Which control strategy staggers the start times of multiple HVAC units to reduce peak electrical demand?

Accepted Answer

Load shedding / demand limiting

Answer

Load shedding or demand limiting staggers equipment startups to avoid simultaneous peak demand spikes on the electric bill.

Question 4

What does a higher SEER rating indicate for a cooling system?

Accepted Answer

Higher seasonal energy efficiency

Answer

SEER (Seasonal Energy Efficiency Ratio) measures cooling output over a season divided by electrical energy consumed; higher values mean better efficiency.

Question 5

In a variable air volume (VAV) system, reducing airflow to 50% of design typically reduces fan energy by approximately:

Accepted Answer

87.5%

Answer

Fan power follows the cube law: reducing airflow to 50% reduces power to (0.5)³ = 12.5% of full load, an 87.5% reduction.

Certified Energy Auditor Certification Practice Test

Certified Energy Auditor Certification Practice Test

Certified Energy Auditor Certification HVAC Systems and Controls 2