CEA Building Systems & Energy Efficiency 2

Question 1

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

Accepted Answer

Use outdoor air for free cooling when conditions allow

Answer

An economizer uses cool outdoor air directly for space cooling when ambient conditions are favorable, reducing mechanical refrigeration energy.

Question 2

A building's chiller plant has a COP of 4.5. How many kW of cooling are delivered per kW of electrical input?

Accepted Answer

4.5 kW

Answer

COP (Coefficient of Performance) directly equals the ratio of cooling output to electrical input, so COP 4.5 means 4.5 kW cooling per 1 kW electricity.

Question 3

Which metric best describes the seasonal cooling efficiency of a residential air conditioner in the US?

Accepted Answer

SEER

Answer

SEER (Seasonal Energy Efficiency Ratio) accounts for varying temperature conditions across a cooling season, making it the standard US residential efficiency metric.

Question 4

In a variable air volume (VAV) system, energy savings over a constant volume system come primarily from:

Accepted Answer

Reduced fan power at part load via cube law

Answer

Fan power follows the affinity laws — reducing airflow by 50% reduces fan power by approximately 87.5% (cube law), yielding substantial energy savings at part load.

Question 5

What is the purpose of a thermal break in a window frame or curtain wall assembly?

Accepted Answer

Prevent conductive heat transfer through the frame

Answer

A thermal break is a low-conductivity material inserted between interior and exterior frame elements to interrupt conductive heat flow and reduce U-factor.

(CEA) Certified Energy Analyst Practice Test

(CEA) Certified Energy Analyst Practice Test

CEA Building Systems & Energy Efficiency 2