CEM HVAC and Building Envelope 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 cool outdoor air directly for space cooling when outdoor conditions are favorable, reducing or eliminating mechanical refrigeration energy.

Question 2

Which metric best describes the overall thermal resistance of a building's entire envelope assembly?

Accepted Answer

R-value

Answer

R-value measures thermal resistance; higher R-values indicate better insulating performance across the full assembly.

Question 3

A chiller's COP is 4.5. How many kW of cooling does it deliver per kW of electrical input?

Accepted Answer

4.5 kW

Answer

COP (Coefficient of Performance) equals cooling output divided by energy input, so a COP of 4.5 means 4.5 kW of cooling per 1 kW of electricity consumed.

Question 4

What does 'infiltration' refer to in building energy analysis?

Accepted Answer

Uncontrolled air leakage through gaps in the building envelope

Answer

Infiltration is the uncontrolled flow of outdoor air into a building through cracks, gaps, and openings in the envelope, increasing heating and cooling loads.

Question 5

Which HVAC system type delivers conditioned air at variable airflow rates to match changing loads?

Accepted Answer

Variable Air Volume (VAV)

Answer

VAV systems modulate supply air volume to zones based on demand, reducing fan energy significantly at part-load conditions.

(CEM) Certified Emergency Manager Practice Test

(CEM) Certified Emergency Manager Practice Test

CEM HVAC and Building Envelope 2