Course: HET 273 - Pneumatic, Electric and DDC Automation - Spring 2015

Unit 1 Outline

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Unit 1 Outline

Objectives

This week’s assignments will support the HVAC learner to:

- Understand comfort
- Describe the 5 requirements of comfort
- Understand Temperature
- Understand Humidity
- Explain the Thermodynamic Laws
- Explain Heat Transfer
- Understand Psychometrics
- Explain the Psychometric Chart

Introduction

In the HVAC/R industry the systems use many different controls to maintain temperature, humidity, and ventilation requirements. The HVAC/R technician must have understanding of properties of air, comfort, and heat transfer. Without this, the technician will struggle with the simplest problems. This week’s assignment will give a review and understanding of HVAV fundamentals.

This Weeks Learning Objectives

1. 1.     Comfort
  1. Comfort is what condition?
  2. What are the requirements of comfort?
  3. What is discomfort?

1. 2.     Comfort requirement
  1. What is humidity?
  2. What is circulation?
  3. What is ventilation?
  4. IAQ

1. 3.     Thermodynamics
  1. Explain first law of thermodynamics
  2. Explain second law of thermodynamics

1. 4.     Heat measurement
  1. Sensible heat
  2. Latent heat

1. 5.     Heat Transfer
  1. Conduction
  2. Convection
  3. Radiation

1. 6.     Psychrometrics
  1. Properties of air
  2. Dry bulb
  3. Wet bulb
  4. Enthalpy
  5. Read psychometric chart

1. 7.     Use of test instruments
  1. Thermometer
  2. Hygrometers
  3. Sling psychrometer

Summary

1. Requirements of comfort are temperature, humidity, ventilation, circulation, filtration
2. Ventilation is the process of introducing fresh air into a building
3. Circulation is the movement of air through building
4. Relation humidity is the amount of moisture in air compared to the amount of moisture the air could hold if saturated
5. Enthalpy is the total heat contained in a material
6. Sensible heat is the heat that can be measured by a thermometer
7. Psychometric chart defines properties of the air at various conditions
8. When two properties are known, all others can be found.

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

Vocabulary

- Sensible Heat
- Latent Heat
- Relative Humidity
- Wet Bulb Temperature
- Dew Point
- Enthalpy
- BTU
- Heat Transfer
- Ventilation
- Circulation