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Development of an integrated air handling system for large commercial buildings

Li Song, University of Nebraska - Lincoln


Commercial building energy consumption has increased from 3,661 trillion BTUs in 1949 to 17,397 trillion BTUs in 2002. HVAC systems in large commercial buildings consume about half of the total energy. The energy used by HVAC systems is in excess of the sum total of the building loads. Excess energy usage is primarily caused by simultaneous cooling and heating systems. As one solution to this problem, an all-air AHU system for large commercial building, named Integrated Office Air Handling Unit (OAHU) system, has been developed in this study. This dissertation covers: ^ Description of the new system. A summary of conventional AHU systems for large commercial buildings, and the advantages and disadvantages of conventional systems as found in a literature review, is presented. A new all-air system is designed with the following three features: (1) the system transfers interior zone heat gains to the exterior zone; (2) the system separates interior zone supply air from the exterior zone supply air; and (3) the new system decouples latent and sensible cooling. ^ Development of system optimal operation schedule. The OAHU system can introduce outside air into the building through either the interior zone or the exterior zone outside air duct, or both. The benefit of the OAHU system is the flexibility of the outside air intake. To minimize energy consumption with an acceptable or improved IAQ, the optimal outside air intake schedule is achieved using the objective function of the energy consumption. ^ Evaluation of OAHU system energy performance. Analytical energy consumption models have been developed for the OAHU system and two conventional all-air AHU systems. Energy performance is compared between the OAHU system and two conventional AHU systems. ^ Implementation of the system. Two case buildings are studied. The effectiveness of the system is measured by projecting the potential thermal savings, estimating the system retrofit, and conducting a cost analysis. ^ Conclusion of the research. The study has showed that the OAHU system is a cost-effective way to reduce or eliminate simultaneous cooling and heating consumption to improve energy system performance of large commercial buildings. Suggestions for future work, based on this research, are proposed. ^

Subject Area

Engineering, Civil|Engineering, Mechanical

Recommended Citation

Song, Li, "Development of an integrated air handling system for large commercial buildings" (2004). ETD collection for University of Nebraska - Lincoln. AAI3159563.