313D Load Calculation and Blueprints 2 — Questions and Answers
Question 1: Which ACCA manual is the industry standard for residential cooling and heating load calculations?
- Manual J (Correct answer)
- Manual D
- Manual S
- Manual T
Correct answer: Manual J
ACCA Manual J is the nationally recognized standard for calculating residential heating and cooling loads.
Question 2: On a residential blueprint, what does the symbol 'CFM' stand for in ductwork notation?
- Cubic Feet per Minute (Correct answer)
- Central Fan Module
- Cubic Flow Measurement
- Cooling Fan Modulator
Correct answer: Cubic Feet per Minute
CFM stands for Cubic Feet per Minute, which is the standard unit for measuring airflow volume in HVAC systems.
Question 3: When calculating cooling loads, which factor accounts for heat transmitted through walls, ceilings, and floors?
- Conduction load (Correct answer)
- Infiltration load
- Internal load
- Solar radiation load
Correct answer: Conduction load
Conduction load accounts for heat transfer through the building envelope, including walls, ceilings, and floors.
Question 4: What does a dashed line typically represent on a mechanical floor plan?
- Hidden or overhead ductwork (Correct answer)
- Electrical conduit
- Plumbing drain lines
- Structural beams
Correct answer: Hidden or overhead ductwork
Dashed lines on mechanical plans typically indicate ducts or components located above or below the primary plane of view.
Question 5: In a Manual J calculation, what is the design temperature difference (DTD)?
- Difference between outdoor design temp and indoor setpoint (Correct answer)
- Daily temperature swing outdoors
- Temperature drop across the evaporator coil
- Temperature rise across the heat exchanger
Correct answer: Difference between outdoor design temp and indoor setpoint
The design temperature difference is the difference between the outdoor design dry-bulb temperature and the desired indoor setpoint temperature.
Question 6: Which blueprint drawing type shows a view from directly above, revealing room layouts and duct routing?
- Floor plan (Correct answer)
- Elevation view
- Section view
- Detail drawing
Correct answer: Floor plan
A floor plan is a top-down view showing room layouts, walls, and the routing of ductwork on that level.
Question 7: What does the 'R-value' represent when reading insulation specifications on blueprints?
- Thermal resistance of the insulation material (Correct answer)
- Relative humidity rating
- Refrigerant charge value
- Roof pitch ratio
Correct answer: Thermal resistance of the insulation material
R-value measures a material's resistance to heat flow; higher R-values indicate better insulating performance.
313D Load Calculation and Blueprints 2
Which ACCA manual is the industry standard for residential cooling and heating load calculations?