HVAC Energy Efficiency 3

Question 1

What does ASHRAE Standard 90.1 primarily address?

Accepted Answer

Energy efficiency requirements for commercial buildings

Answer

ASHRAE 90.1 sets minimum energy efficiency requirements for the design and construction of commercial buildings and their HVAC systems.

Question 2

An HVAC technician notices condenser coil fins are bent and restricting airflow. What is the most likely energy impact?

Accepted Answer

Increased condensing pressure and reduced system efficiency

Answer

Restricted condenser airflow raises head pressure, forcing the compressor to work harder and reducing overall system efficiency.

Question 3

Which factor primarily determines the Energy Efficiency Ratio (EER) of a cooling system?

Accepted Answer

Cooling capacity in BTU/h divided by power input in watts at a specific test condition

Answer

EER is calculated at a fixed ARI test condition (95°F outdoor, 80°F/67°F indoor) as BTU/h of cooling divided by watts of electrical input.

Question 4

What is the role of thermal expansion valves (TXV) in maintaining efficiency?

Accepted Answer

They maintain consistent superheat to maximize evaporator use without liquid slugging

Answer

TXVs modulate refrigerant flow to maintain a set superheat, ensuring the evaporator is fully used without allowing liquid refrigerant into the compressor.

Question 5

Which building envelope feature most reduces HVAC cooling loads in hot climates?

Accepted Answer

High-reflectance roofing (cool roof)

Answer

Cool roofs reflect solar radiation, reducing roof surface temperatures and heat transfer into the building, directly lowering cooling loads.

HVAC Practice Test

HVAC Practice Test

HVAC Energy Efficiency 3