Air Conditioning Repair Heat Load Calculations and System Sizing 3

Question 1

A home requires 36,000 BTU/hr of cooling capacity. What is the correct equipment size in tons?

Accepted Answer

3 tons

Answer

Dividing 36,000 BTU/hr by 12,000 BTU/hr per ton equals 3 tons, which is the correct equipment size for this load.

Question 2

What happens when an air conditioning system is undersized relative to the building's peak cooling load?

Accepted Answer

It runs continuously but cannot maintain the desired setpoint on peak days

Answer

An undersized system will run continuously at full capacity but still be unable to maintain the thermostat setpoint during peak outdoor design conditions.

Question 3

Which software platform is widely used by HVAC contractors to perform Manual J residential load calculations?

Accepted Answer

Wrightsoft Right-Suite

Answer

Wrightsoft Right-Suite (and similar programs such as Elite RHVAC) automate the Manual J calculation process, reducing errors and saving time compared to manual calculations.

Question 4

In load calculations, the U-value of a building assembly describes which property?

Accepted Answer

The overall heat transfer coefficient of the assembly

Answer

U-value is the overall heat transfer coefficient, expressing how much heat flows through an assembly per square foot per degree of temperature difference; it is the mathematical inverse of R-value.

Question 5

What does the ventilation load component account for in an HVAC load calculation?

Accepted Answer

Conditioning intentionally introduced outdoor fresh air

Answer

The ventilation load accounts for the sensible and latent energy required to condition the fresh outdoor air that is intentionally introduced into the building to meet indoor air quality standards.

Air Conditioning Repair Practice Test

Air Conditioning Repair Practice Test

Air Conditioning Repair Heat Load Calculations and System Sizing 3