HVAC - Variable Air Volume Systems

In HVAC - Variable Air Volume Systems , you'll learn ...

• The components of a variable air volume (VAV) system and how the system operates
• The relative merits of VAV and constant air volume (CAV) systems
• Why VAV systems fell into disfavor in the past and why they are making a comeback
• VAV system control options

Overview

Preview a portion of this course before purchasing it.

Credit: 6 PDH

Length: 121 pages

In central air conditioning systems there are two basic methods for delivering air to the conditioned space: constant air volume (CAV) systems, and variable air volume (VAV) systems.

As the name implies, constant volume systems deliver a constant air volume to the conditioned space irrespective of the load. VAV systems, on the other hand, are designed to simultaneously meet a variety of cooling and heating loads in a relatively efficient manner. The system achieves this by varying the distribution of air depending on the cooling or heating loads of each area. The air flow variation allows for adjusting the temperature in a single zone without changing the temperature of air in the whole system, minimizing any instances of overcooling or overheating. This flexibility has made this one of the most popular HVAC systems for large buildings with varying conditioning needs such as office buildings, schools, or apartments.

This 6-hour course covers HVAC air distribution systems with the focus being on Variable Air Volume (VAV) systems.

Specific Knowledge or Skill Obtained

This course teaches the following specific knowledge and skills:

• The operational philosophy of variable air volume (VAV) systems
• Advantages and disadvantages of VAV systems vs. CAV systems
• Applications that favor VAV systems over other options
• Differences between pressure dependent, pressure independent and volume limiting VAV boxes
• The various types of fans used in air handling systems including forward curved, backward curved, radial and aerofoil construction
• Types of cooling coils used in air handling systems and which among face split, vertical split and interwined coils is appropriate for VAV systems
• How to optimize duct design in VAV systems
• Duct pressure classification and how it is used in selecting appropriate duct sheet thickness
• Duct design using equal friction method relative to the static regain and T-method
• Types of outlets and which parameters govern their selection
• The difference between fan powered, single duct, dual duct and bypass VAV boxes
• Types of VAV controls, including direct digital controls
• Acoustical considerations in the design of VAV systems
• Common instruments used in acceptance testing and monitoring of VAV systems

Certificate of Completion

You will be able to immediately print a certificate of completion after passing a multiple-choice quiz consisting of 30 questions. PDH credits are not awarded until the course is completed and quiz is passed.