FC Load Calculations & Equipment Sizing 2

Question 1

What is a common negative consequence of installing an oversized furnace in a residence?

Accepted Answer

Short cycling, leading to reduced comfort and increased wear

Answer

Higher annual fuel efficiency

Answer

Lower installation cost due to simpler controls

Answer

Improved indoor air quality from longer run times

Question 2

Which ACCA manual provides guidance specifically for residential duct system design?

Accepted Answer

Manual D

Answer

Manual J

Answer

Manual S

Answer

Manual T

Question 3

What is the maximum recommended oversizing percentage for a gas furnace according to ACCA Manual S guidelines?

Accepted Answer

40%

Answer

10%

Answer

25%

Answer

100%

Question 4

A home has a calculated design heating load of 60,000 BTU/h. Which furnace output capacity is the most appropriate selection?

Accepted Answer

80,000 BTU/h output

Answer

40,000 BTU/h output

Answer

120,000 BTU/h output

Answer

20,000 BTU/h output

Question 5

How does a home's infiltration rate affect the heating load calculation?

Accepted Answer

Higher infiltration increases heating load by introducing cold outside air

Answer

Higher infiltration decreases heating load by bringing in fresh air

Answer

Infiltration only affects cooling loads, not heating loads

Answer

Infiltration rate cancels out with exhaust fan calculations

Question 6

What is the purpose of calculating 'sensible heat ratio' (SHR) in HVAC equipment sizing?

Accepted Answer

To balance the proportion of sensible versus latent cooling capacity

Answer

To determine the correct furnace input BTU rating

Answer

To calculate the flue gas temperature rise

Answer

To size the gas supply line diameter

Question 7

When performing a load calculation for a home addition, what must the technician verify about the existing furnace?

Accepted Answer

Whether the existing furnace has sufficient capacity to handle the additional load

Answer

Whether the furnace has a variable-speed blower

Answer

Whether the furnace was installed by a licensed contractor

Answer

Whether the furnace uses a two-stage gas valve