This paper is based on findings resulting from ASHRAE Research Project RP-1354.

Software is a critical component of the design, construction, and operation of HVAC&R systems and equipment in buildings, yet seldom does one software application communicate information to another. The lack of compatibility between applications leads to information about the building and its systems being re-interpreted and re-entered for each application causing inefficiency and even information loss. Draft Guideline 20, titled "XML Definitions for HVAC&R" is attempting to establish a common data exchange format for the description of commodity data and HVAC&R information using eXtensible Markup Language, XML. The research project focused on four of the twelve Use Cases described in draft Guideline 20. For each Use Case, detailed process steps describing the Use Case were elaborated. From the detailed process steps, transfers of information were extracted showing the groups of data that were needed to communicate between various parties. After analysis, the 107 Data Groups identified were named and defined. Using these Data Groups, three selected existing data models were examined in detail and 4350 Data Elements were identified. Only 37 of these Data Elements were found in all three existing data models.

Units: Dual