COMPUTING IN CIVIL ENGINEERING 805

integrate them and enable the system operator to deploy them in real-world systems。

RESEARCH APPROACHES

This research first explored the existing computerized approaches and analyzed their information requirements。 Based on the findings, functional requirements were identified for an integrated framework to address the vision described in section 2。 Finally, a prototype application was developed to test the feasibility of the envisioned framework and investigate challenges associated with that framework。 The following sections discuss these three steps in the research。

Analysis of information requirements for the existing computerized approaches

Based on the review of the existing computerized approaches, we selected thirty-two scientific publications for use in identification of information requirements。 The main goal in selecting publications was to have a perse set of approaches to be incorporated in the initial framework。 Hence, the criteria for selection were to include the publications that cover different types of approaches and that are developed by different researchers and/or organizations。

According to their information sources, the identified information requirements can be categorized into two groups: dynamic and static information items。 Static information items are documented in drawings, manuals and spreadsheets。 They only change when the configuration of the building layout or HVAC systems is changed。 For example, dimensions and materials of the building elements typically do not change frequently after construction。 A summary of the static information items is listed in Table 1。

Table 1 Summary of the static information requirements

Information requirement Example

Building Building layout Total size of the windows in Room  01。

Material of building elements Material of the external walls。

Occupancy and equipment load Number of occupants in Room 01。

Sensor Type of measurement Temperature, pressure, flow rate, etc。

Measured object Supply air duct of a VAV  box。

Data interface for acquiring the measurement BACnet device ID and object ID of the HVAC components。

Controller Controlled device Speed of the supply fan for an AHU。

Communication interface ID of the BACnet device and object。

Set-point Temperature set-point for a thermal zone。

Actuator Controlled device Damper in a VAV  box。

Data interface for acquiring the status of the controlled device ID of the BACnet device and object。

Relationship Spatial relationship Space where the temperature sensor is located。

Topological relationship Connection between the air terminals and the VAV  box。

Functional groups of the HVAC components Components which serve the temperature control of a space。

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Dynamic information items are generated by the components of the HVAC systems and the framework。 The identified dynamic information items include the variables in HVAC systems and outputs of the computerized approaches。 Variables in HVAC systems include the sensor measurements, set-point values, control signals, and working status of the controlled HVAC components。 These information items are typically collected by the HVAC systems。 To acquire these information items, the framework needs the capability to communicate with the HVAC systems。  Examples of the outputs of computerized approaches include the type of fault and faulty components which are detected by the FDD approaches。