Overview of Learn HVAC

Learn HVAC is an interactive tool designed to introduce fundamental HVAC concepts to students. The tool makes these concepts come alive by creating a real-time simulation of a simple HVAC system.

Students can move through the 3D simulation, viewing each system component as it operates. These components -- the VAV box, fan economizer and so on -- visually change according to user inputs and simulation calculations. Air particles change color. Water flows through the coils.

A system view within Learn HVAC
Viewing the "system" within Learn HVAC. The blue navigation control in the lower left of the 3D image allows the student to zoom in on each component.

Behind the user interface, Lawrence Berkeley National Lab's SPARK simulator crunches the numbers, updating the simulation every few seconds with realistic data. As the student changes input data, SPARK adjusts the output variables accordingly.

There are over 200 SPARK variables controlling the system's performance. Changing the defaults for these variables will adjust the system's behavior and can thereby create different educational situations. To make this customization process easier, Learn HVAC comes with a companion "Instructor Tool" website that allows instructors and administrators to create learning "scenarios," complete with movies to add contextual clues.

A system view within Learn HVAC
The Instructor Tool allows the instructor to create customized learning "scenarios" as well as manage users and view reports.

The Learn HVAC tool uses videos and other information to present problem situations, which will facilitate understanding of the operating principles of HVAC system components. This tool allows users to diagnose basic equipment problems at the component and system level.

Pedagogical Model Used

Learn HVAC uses goal-oriented, problem-based case study methods to find solutions to complex system-level equipment problems. It proomotes a team approach to problem-solving and encourages communications and interactions within teams and between teams and course instructors. See also the "Six Step Learning Process."

SPARK simulations

SPARK is a sophisticated equation-solving software package developed at Laurence Berkeley National Lab. One of its uses has been to simulate the detailed operations of HVAC systems, components and their controls. For the Learn HVAC, a number of component models have been created within SPARK to describe an air handling system and with a series of typical components.

When a scenario is started, the SPARK simulation is not automatically started. The user starts and stops SPARK by clicking a button on the screen. Once the user has started the SPARK simulation, the screen comes to life with the second-by-second simulation output. The user can stop SPARK, change input variables to get a different effect, and then start it again.

The simulation normally runs much faster than real time, so that the user can quickly observe system behavior changing over time. The current “normal” setting is for the simulation to run 100 times faster than real time. The user can change this relative speed. 

3D Animation Engine

Learn HVAC uses a 3D animation engine that has been developed in Flash ActionScript 3.0. The use can observe realistic animations of how the HVAC system and its components are operating. Water moves through pipes and air particles move through the ductowrk and into the room and plenum. Fans spin and dampers move according to the system status.

The animations do require a certain level of processing power (an average desktop or laptop purchased in the last few years is usually fine). Learn HVAC has the option, however, to scale back or turn off the animations to accomodate earlier machines. A popup "Performance" dialog box allows the user to modify seveal system performance parameters.

Inter-process communication

Every few seconds the user interface and the SPARK simulator communicate with each other. If the user has changed any inputs they are sent to SPARK, while SPARK output variables are collected and used to update the user interface. These output values drive the animations, information displays and charts.

Graphic User Interface (GUI)

The user can control all program actions via a GUI. Built in Flash and based on the ARP framework, the interface provides a seamless environment for viewing different portions of the HVAC system. Input variables are easy to access and update. Output variables appear at the bottom of the screen and can be graphed against each other.

Primary Intended Users

The primary intended users of this first version of Learn HVAC are students and instructors in 2-year technical degree HVAC and ECT programs in community colleges.

Other Possible Users

Future versions of Learn HVAC are being planned. Some versions would address the needs of other types of users with different needs for software-based analysis, presentation, and interaction. Other possible users may include:

  • Building operators
  • Engineers focused on the operation, commissioning, retrofitting, and retro-commissioning of building HVAC systems.
  • Students and professors in 4-year universities with technical HVAC programs or Schools of architecture
  • High school students
  • Participants in union apprentice programs

What’s Included with Learn HVAC

Learn HVAC is comprised of the following components:

  • Flash simulations
  • Instructional video and audio files
  • Multiple interactive problem scenarios
  • Extensive context-sensitive information about systems and components
  • 12 forms:
    • Need to Know Board
    • Troubleshooting Chart
    • Concept Map
    • Learning Log
    • Observation Form
    • Resource Template
    • Checklist - Critical Thinking and Team Interactions
    • Scoring Rubric for Evaluation of KSA PBCS
    • Talk Back Sheet
    • Reflection Essay
    • Instructor's Scoring Guide