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Engineering Laboratory

Building Energy & Environment Division

IBAL Overview

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The Intelligent Buildings Agents Laboratory (IBAL) is designed to emulate a small commercial building. The air system contains the zones and the equipment used to condition the air for the zones, while the hydronic system contains the equipment used to provide cooling for the air system. 

Video Tour

Available at at: https://www.nist.gov/video/tour-intelligent-building-agents-laboratory

Tour of the Intelligent Building Agents Laboratory
Tour of the Intelligent Building Agents Laboratory
The Intelligent Building Agents Project will demonstrate the feasibility of intelligent agent control techniques for reducing the cost of operating HVAC equipment in commercial buildings by optimizing the performance of interacting building systems. The Intelligent Building Agents Laboratory is the key research infrastructure for this work. The lab contains the major equipment that exists in real commercial buildings. The tour shows the equipment in the air system, or building, including an air handling unit that generates repeatable weather conditions. The tour ends on the water side of the system, which includes two chillers and an ice-on-coil thermal storage tank.All product and company names shown in the video are trademarks or registered trademarks of their respective holders and does not imply any affiliation with or endorsement by NIST.

The lab contains 4 zones, called zone simulators (ZS), each of which contain an electric heater to generate sensible loads and a steam spray humidifier to generate latent loads. In addition, there is a water-to-water heat exchanger that can be used to generate a load in addition to, or instead of, the zones, allowing the hydronic and air systems to be operated independently.

Figure 1 The four zone simulators
Figure 1 The four zone simulators

In the air system, each zone is connected to a variable air volume (VAV) box, which contains a damper to modulate the airflow into the zone and an electric heater for reheat.  The VAVs are served by air handling units (AHU); each AHU serves two VAVs. The AHUs contain supply air fans and a cooling coil; the air and hydronic systems are connected via the cooling coils.

Figure 2 The four VAVs
Figure 2 The four VAVs
Figure 3 The two AHUs
Figure 3 The two AHUs

Cold propylene glycol is supplied to the cooling coils by any combination of two chillers, an ice thermal storage tank, or a water side economizer. One of the chillers is used to build ice during times when electrical rates are low and it can then be melted to meet all or part of a load during times when electrical rates are higher. The chillers and water side economizer receive cooling from a condensing loop, which takes the place of the cooling tower that would be used in a real building.

Figure 4 The two chillers
Figure 4 The two chillers
Figure 5 Ice thermal storage tank
Figure 5 Ice thermal storage tank

One final component is the outdoor air unit, which is used to generate repeatable weather conditions.

Figure 6 Outdoor air unit for weather generation
Figure 6 Outdoor air unit for weather generation

All sensors and equipment in the laboratory are connected to a custom-built data acquisition system that is run by a control program.

Figure 7 Data acquisition system
Figure 7 Data acquisition system

Schematic

Schematic with Data Acquisition Channel Numbers

Contacts

FOR MORE INFORMATION, CONTACT:

Created July 7, 2021, Updated July 30, 2021