Title: Unit 11 Outline
Course: HET 191 HVACR Heat Load > Section: HET 191 HVACR Heat Load

Unit 11 Outline

Unit 11 Outline
Unit 11 Outline

Type of Ventilation Systems

Objective

After studying this week’s assignment, the HVAC learner should be able to:
- Develop an appreciation and the importance of the Manual D
- Understand the different types of issues that can effect air flow
- Convert heating loads into air capacity
- Recognize the different types of duct systems
- Understand the benefits of each type duct systems
- Understand how the duct system can affect the heat load of the building

Introduction

Once the HVAC technician has determine the heat load and air capacity, and then it will become necessary to size the ductwork for the structure. Not only the ducts have to be the correct size for the proper air flow the equipment system blower need to be able to handle the volume of air required to heat and cool the building. There are different ways to size the ducts in a home; however, the equal friction is popular way to design the duct system.

Perimeter Loop System

Radial System

Trunk And Branch System

- Extended Plenum Trunk
- Graduated Trunk

Using Blueprints to Lay Out the System

- Ductwork Location
- Register and Grille Location

Sizing the Ducts

- Equal Velocity Method
- Equal Friction Method

Review the vocabulary terms listed below and look up their definitions / descriptions before taking the Vocabulary Quiz.

Vocabulary

Terms

- Static pressure
- Total Pressure
- Velocity pressure
- CFM
- Air Changes
- Psychometric