Title: Unit 10 Outline
Course: HET 191 HVACR Heat Load > Section: HET 191 HVACR Heat Load

Unit 10 Outline

Unit 10 Outline
Unit 10 Outline

Understanding Air Flow

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
- Use charts, tables, and forms to calculate the air volume
- Locate manufacture data sheet and information sheets to choose the proper type of equipment
- Choose the type of equipment

Introduction

After the HVAC equipment has the chosen based on the heat load of the structure, the amount of air through the system should be determined. Therefore, the Btu/h output of the HVAC system will be converted into CFM of air to be delivered through the ductwork to each room. Once the system capacity for both the heating and cooling needs has been determine, then every room heat loads must be painstaking worked out separately because the heating and cooling air flow requirements will be different.

Air Volume

- Determine the CFM

Static Pressure in Ducts

- Causes of Static Pressure

Sizing Ducts

- Factors of sizing Ducts

Converting Btu’s to CFM

Air Changes

Psychometric

- Properties of air
- Wet Bulb
- Dry Bulb
- Dew Point
- Relative Humidity (RH)
- Grains of Moister
- Enthalpy

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