Air Conditioning Repair Heat Load Calculations and System Sizing 2

Question 1

What type of heat gain is caused by heat transferring through walls, roofs, and floors due to a temperature difference?

Accepted Answer

Conductive heat gain

Answer

Conductive heat gain occurs when heat flows through solid building materials from a warm exterior surface to a cooler interior, governed by the material's U-value and the temperature difference.

Question 2

In the northern hemisphere, windows facing which direction typically contribute the greatest solar heat gain during summer afternoons?

Accepted Answer

West

Answer

West-facing windows receive direct sunlight during the afternoon when outdoor temperatures are at their highest, resulting in the greatest peak solar heat gain.

Question 3

What does the latent heat load in an air conditioning system represent?

Accepted Answer

Moisture that must be removed from the air

Answer

Latent heat load is associated with moisture (water vapor) removal from the air; removing latent heat does not lower air temperature but reduces relative humidity.

Question 4

ASHRAE design outdoor conditions used in load calculations are based on which statistical criteria?

Accepted Answer

A temperature exceeded only 1% of annual hours

Answer

ASHRAE design conditions represent outdoor temperatures that are exceeded only 1% (or 2.5%) of all annual hours, providing a statistically reliable but not absolute worst-case design point.

Question 5

How does uncontrolled air infiltration affect a building's cooling load?

Accepted Answer

It adds both sensible and latent load by introducing unconditioned outdoor air

Answer

Infiltration introduces hot, humid outdoor air through gaps and cracks in the building envelope, adding both sensible heat (temperature) and latent load (moisture) that the AC system must handle.

Air Conditioning Repair Practice Test

Air Conditioning Repair Practice Test

Air Conditioning Repair Heat Load Calculations and System Sizing 2