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Objective:
To continue the development of a standards-based infrastructure supporting the design, analysis, specification, procurement, installation, operation, and maintenance of heating, ventilation, air-conditioning, and refrigeration (HVAC/R) systems.

Background:
Heating, ventilation, air-conditioning, and refrigeration systems are essential elements of any modern building, plant, or ship---generically, any facility.  They maintain the comfort and health of human occupants and establish the required operating conditions for industrial processes and commerce.  Increasingly, facility owners are striving to optimize not just the performance and reliability but also the life-cycle cost of their HVAC/R systems.  Over the useful life of a facility, the installed cost of the equipment making up the HVAC/R systems is swamped by the operation and maintenance costs.  Beyond the performance and cost goals of individual owners, reducing energy consumption is a national goal.

It has long been recognized that complete and timely information must be shared among all the people who deal with HVAC/R systems if life-cycle goals are to be achieved.  Additionally, it has become especially apparent during the last two years that this information is even more necessary for improving homeland security because of the intimate role HVAC/R systems play in the response of a building to adverse events.

The Industry Foundation Classes being developed by the International Alliance for Interoperability using ISO/STEP technology and already being implemented by, e.g., the BLIS project members, are the best available technology for representing and exchanging this information.  Prior to FY03, this SIMA project has worked to expand the IFC representation of HVAC/R equipment.  During FY03, this project focused on the development of an HVAC/R equipment repository derived from the IFC representations in order to support a specific scenario - the analysis, i.e., the selection, of equipment alternatives.  The repository includes XML schemas derived from the IFC Express specifications for doors, windows, and pumps.  In addition, the repository contains documentation for the schemas as well as twenty-eight instance documents for various models of doors, forty instance documents for various models of windows, and fifteen instance documents for various models of centrifugal pumps manufactured by four different companies.  In order to continue the forward progress toward the overarching objective of developing a standards-based information infrastructure supporting the design, analysis, specification, procurement, installation, operation, and maintenance of heating, ventilation, air-conditioning, and refrigeration systems, this proposal for FY04 builds upon the results achieved in FY03 and establishes the foundation for implementing access to the repository via web services.  

The first task is to expand the collection of equipment type schemas along with the associated instance documents containing manufacturers’ data.  The expansion will provide sufficient variety to support various use cases for the repository including: (1) data selection and exchange with applications such as BFRL’s CONTAMW software for multizone airflow and contaminant transport analysis as well as BFRL's Virtual Cybernetic Building Testbed; (2) identification and selection of functionally equivalent replacements for HVAC/R equipment that has reached the end of its life-cycle; (3) identification and selection of new HVAC/R equipment during the facilities design process; (4) e-business procurement scenarios wherein customers try to locate, search, and select from available Web-based commodity HVAC/R equipment catalogs; and (5) derivation of semantic mappings between the IFC models and the results of the AEX effort, a companion SIMA project. 

The second task is to begin implementing the infrastructure for establishing access to the repository using web services.  The deliverable for this task will be a viable method for unambiguous and user-friendly access to the repository, including the retrieval of specific data elements via services.  Such retrieval capabilities will not only satisfy the needs of use cases (1) through (4) but will provide an important source of experiential results needed for comparing data exchange methodologies with those being tested in the AEX e-business effort. 

In the first phase of this second task, the repository will be ported from a straightforward, static web page to a back-end database management system  (DBMS).  Clearly, as the variety of equipment types expands and the corresponding number of instance documents grows, a more sophisticated inventory management system will be required.  This phase of the task includes pre-implementation analysis of the various DBMS' available for managing XML documents as well as design, development, and testing of the database. 

The second phase of this task, spanning the remainder of FY04 and extending into FY05, includes the analysis and implementation of a fully layered web services protocol stack to support:  (1) message transport between applications and the database/repository for data access and retrieval; (2) encoding of the messages using, at first, XML-RPC (Remote Procedure Calls) and, possibly as an enhancement depending upon the results of the design analysis, SOAP (Simple Object Access Protocol); (3) description of the provided services for the public interface to the repository using WSDL (Web Services Description Language); and (4) a services discovery layer using UDDI (Universal Description, Discovery, and Integration) to support the discovery and identification of the applicable repository services via the Web, which would greatly improve the functionality of applications seeking out the repository and its services.