Title: Lab Assignment
Course: HET 230 - Spring 2015 > Section: HET 230 - Spring 2015

Lab Assignment

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Unit 4 Lab Assignment

HET 230 Week 4 Lab: Duct Calculator

NAME  ____________________________  DATE  ____________________

Use a duct calculator to solve the following air flow questions. Assume a 0.08” friction loss per 100 feet for all problems.

1. What size round duct is needed for 1000 CFM air flow quantity? _________________________________________________________________________
2. What size rectangular duct would be needed if the duct height were 8”? _________________________________________________________________________

1. What would the velocity of the air for the above duct be? ___________________________

1. How many CFM would a duct that is 20” x 10” carry? ______________________________

1. What would the velocity be? __________________________________________________

1. A round duct is 12”, What CFM could it carry? ____________________________________

1. What size rectangular duct would carry the same CFM? ____________________________

1. What would the velocity be? __________________________________________________

Using a Furnace which has a supply trunk duct; preform for the following questions.

1. What is the supply trunks size? _____________________
2. How many CFM is it capable of carrying at 0.08” w.c. friction loss? _____________________________
3. What will the velocity be? ____________________________
4. What is the aspect ratio of the duct? ________________________
5. What size round duct could deliver the same CFM air volume? _______________________

Using a Furnace which has a return drop duct; preform the following questions.

1. What are the dimensions of the return drop going to the furnace? _____________________
2. What is the aspect ratio? ________________________
3. What is the CFM volume capability if the friction loss is being maintained at 0.08” w.c.? ____________
4. What would be the velocity of the air? _______________
5. What do you notice about the velocity in all of the above questions? __________________________________________________________________________________________________________________________________________________
6. What do you notice about the friction loss per 100 feet in all of the above questions? __________________________________________________________________________________________________________________________________________________

Click on the file below to download the supporting documents for Lab Assignment
- Ref1 Friction Chart.pdf (369.67 KB)
- T3 Equiv Duct Size Chart.pdf (250.22 KB)
- T1 Velocity Pressure.pdf (63.51 KB)