Overview of Learn HVAC
Learn HVAC is an interactive computer-based education (CBE) tool designed to introduce fundamental HVAC concepts to students and to others in the building industry (building operators, etc.).
Several key elements come from work produced under a 3-year NSF grant:
- A set of accurate component simulation models for air-handling components
- A series of 3D models and related animations
- A graphic user interface
- A password-protected instructor website
A subsequent CEC-funded effort has been intended to improve on the original NSF-funded products, to add key new energy-related features, and to expand the potential audiences to include more building industry participants. The new CEC-funded software features include:
- Adding energy and peak demand models to existing SPARK HVAC component models for a typical air-handling unit (AHU).
- Adding EnergyPlus to the CBE tool to integrate annual, monthly, and diurnal energy impacts to the existing short term (second-by-second) dynamic system operations focus of the existing SPARK component models.
- Developing new component models for boiler, chiller, cooling tower to the existing set of component models for AHU components.
- Developing new CBE scenarios that integrate the new and existing CBE features.
These additions enhance the capabilities of the existing CBE tool and allow the tool to be more in line with CEC’s core energy mission.
Background and Previous Versions
Learn HVAC is a third-generation computer-based education (CBE) tool that is built upon earlier first and second generation tools:
First Generation HVAC CBE Tool (1994-1999 and 2001)
The first generation HVAC CBE tool is HVAC Energy Primer (aka Energy Trainer). This was first developed during 1994-1999 as a CD-based product. It was funded by US DOD, US DOE, and US EPA, and was developed in Adobe Authorware as an interactive multimedia CBE tool by a team of The Deringer Group (TDG), CTG, and others. The software IP is shared by TDG and CTG.
HVAC EP was intended to provide an interactive version of the HVAC portion of the US FEMP Energy Manager’s training manual. HVAC EP contains 4 hours of energy efficiency technical content that span a number of topics. In addition it contains a Problem-Based Case Study exercise that allows users to improve the performance of an existing HVAC system with 8 faults.
In 2001, TDG modified to software to permit it to be accessed on the Internet as a web-based product. This has been available at no charge at www.ecoadvisor.org since 2001.
Second Generation HVAC CBE Tool (2004-2008)
HVAC ePrimer is the second generation of this set of HVAC CBE tools. This version was developed during 2004-2008 in two parts intended primarily as part of community college HVAC technician training programs and curriculum development. One part of HVAC ePrimer is downloadable package that runs locally on a MS Windows operating system and is intended for use by students and student teams. It uses 3D animations of accurate simulations to teach HVAC technician students how to better operate, maintain and troubleshoot increasingly complex, digitized HVAC systems and controls in buildings.
The HVAC ePrimer software is using the latest technical education approaches being promoted by the National Science Foundation’s Advanced Technological Education (ATE) program.
Major funding was provided via a 3-year NSF grant that was extended to a 4-year period (without additional funding). The Peralta College District (Laney College) in Oakland also provided $25,000 in funding and The Deringer Group provided in-kind funding of close to $75,000.
Third Generation HVAC CBE Tool (2007+)
Learn HVAC is the third generation of this set of HVAC CBE tools.This version is being developed via two-year CEC funding starting in late July 2007.
Learn HVAC has the following new features that were not in HVAC ePrimer:
- Builds upon several key aspects of the software already developed under the NSF-funded Laney-LBNL-TDG project described above.
- Has the same component models, second-by-second SPARK simulation capabilities, general animation views and sequences, and web-based builds upon.
- Adds energy and peak demand.
- Adds EnergyPlus analysisi
- Uses a new, much more robust software development platform (Adobe Flex), new interactive multimedia software (Flash 9), new charting software (Flex Charts)
- Provides a much more flexible Graphic User interface, with multiple and movable popup windows that can adapt to user screens of varying resolution.
- Can store and retrieve of input and results files, thus permitting persformance and energy comparisons to be made of initial and revised conditions.
Current Status
To date, all of the features just mentioned above have been implemented in draft form. In addition, draft versions have been developed for the first three energy-specific products listed above, namely:
- Adding energy and peak demand models.
- Adding EnergyPlus to the CBE tool
- Developing component models for boiler, chiller, cooling tower
Drafts of all four products should be available for review by the end of calendar year 2008.
Interim Pre-Beta Release of Learn HVAC
Until very recently, Learn HVAC (and its predecessor HVAC ePrimer) were considered to be in early development mode. Software downloads were password-protected and available to only a few people on the development team.
Recently, about mid-June 2008, software downloads have been made available for the "client" portion of the Learn HVAC software intended for student use. The web-based instructor site is not yet available publically, but limited access to this site may be may publically available in the near future.
The currently available “public” version is limited in scope. It only contains the simulation and basic anaimation functionality developed under the NSF grant.
The new energy features being developed under CEC, while in draft form, are not yet stable enough for widespread public use.
More Complete Release of Learn HVAC Expected late in 2008
We anticipate that more complete versions of Learn HVAC that include the new energy features will be available for widespread public review by the end of calendar year 2008.
Open Source Version Expected late in 2008
We anticipate that an open source version of … will be available the end of calendar year 2008. Several key elements of the software need to be refined first.
Need
HVAC systems and controls in buildings are becoming increasingly complex, digitized, and difficult to properly design, construct, operate, maintain, and troubleshoot. Building operators and technicians today must master new computer-based technologies in addition to their traditional skills.
Building Operations
One result is that many buildings are not operating properly, thus providing marginal or poor comfort and quality, while using much more energy than needed. In many cases the energy savings in the building fall far short of the savings promised by the use of advanced technologies.
Several major trends are increasing the complexity and difficulty of properly operating and maintaining buildings.
- Digital control technology is becoming pervasive on both new and existing buildings. Thus, building operators and technicians must master a new set of computer-related skills (e.g., hardware, software, database management, and local area networking) in addition to their traditional skills of HVAC management and repair.
- Regulations and policies are increasingly involved, including new commissioning and sustainability factors.
- Energy performance monitoring, commissioning and retrocommissioning address Increasing energy costs but require advanced capabilities to be effective.
- Security is increasingly important since 9/11 and operators must monitor advanced security systems, initiate emergency response plans, and shut down complex system in the event of environmental attacks.
Energy
Saving energy in buildings involves not just added new widgets and technologies. High efficiency equipment that is not properly installed, calibrated, tested, operated or maintained will likely save far less energy than anticipated. Thus, saving energy also involves training skilled people to design, construct, operate, and maintain the increasingly complex buildings and systems.
One path to improved building performance is to raise the level of understanding of proper:
- Proper, energy-efficient HVAC operations and controls on the part of building operators and technicians, and
- proper system-level troubleshooting methods and approaches to solve problems when they occur.
The energy enhancements now being developed for the Learn HVAC CBE software focus on teaching system-level troubleshooting skills as well as business skills in communications and teamwork.
Overview of Learn HVAC SPARK Simulator
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.
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.
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 promotes 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