FC Load Calculations & Equipment Sizing

Question 1

What is the primary purpose of a Manual J load calculation in furnace installation?

Accepted Answer

To calculate the heating and cooling loads of a structure

Answer

Manual J is the ACCA-approved methodology used to calculate a building's heating and cooling loads, which determines the required furnace capacity.

Question 2

Which unit is most commonly used to express a furnace's heating output capacity in the United States?

Accepted Answer

British Thermal Units per hour (BTU/h)

Answer

Furnace heating capacity in the US is rated in BTU/h (British Thermal Units per hour), which measures the amount of heat the furnace can deliver.

Question 3

Which of the following factors is typically included in a Manual J residential load calculation?

Accepted Answer

Window area and glazing U-value

Answer

Window area and glazing U-value directly affect heat transfer through the building envelope, making them essential inputs to a Manual J load calculation.

Question 4

What does 'design temperature difference' (ΔT) mean in the context of heating load calculations?

Accepted Answer

The difference between indoor design temperature and outdoor design temperature

Answer

Design temperature difference (ΔT) is the difference between the desired indoor temperature and the outdoor winter design temperature, and it drives the magnitude of the heating load.

Question 5

How does increasing a ceiling's insulation R-value affect the calculated heating load?

Accepted Answer

It decreases the heating load by reducing heat loss through the ceiling

Answer

Higher R-value insulation reduces the rate of heat loss through the ceiling, which lowers the total heating load and allows for a smaller furnace.

(FC) Furnace Installation and Maintenance Certification Practice Test

(FC) Furnace Installation and Maintenance Certification Practice Test

FC Load Calculations & Equipment Sizing