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The laboratory air handling unit (LAHU) system for laboratory buildings has been developed and optimized. Theoretical study has concluded that the LAHU with optimal outside air control and optimal heat recovery control significantly reduces thermal energy use, saves pump power consumption and improves office indoor air quality. This paper presents validation experiments of the LAHU energy performance for the winter operation in a large university research building including detailed experimental methodology, procedures and experimental energy savings results. The experiments establish that the LAHU can reduce annual heating energy consumption by over 30% and can reduce heat recovery pump power by over 50%peryear for this typical laboratory building. The experimental validation of the LAHU for the summer operation will be reported in a followup paper.

The Laboratory Air Handling Unit (LAHU) system conditions both the office section and the laboratory section. It improves indoor air quality by maximizing outside air intake to the office section and minimizes thermal energy consumption by re-circulating the office section air to the laboratory section. This paper presents a theoretical linear optimization method and results of optimal outside air control in LAHUs. The optimal outside airflows are expressed as functions of the weather conditions (outside air temperature and enthalpy), office and laboratory airflow rates, office and laboratory supply air temperatures, and four dimensionless parameters that describe the building system and energy characteristics. The optimization method used in this paper can be used to identify the optimal control schedules in other HVAC systems.

The Laboratory Air Handling Unit (LAHU) system for laboratory buildings has been developed and optimized. Theoretical study has concluded that the LAHU with optimal outside air control and optimal heat recovery control significantly reduces thermal energy use, saves pump power consumption and improves office indoor air quality. This paper presents validation experiments of LAHU energy performance in a large university research building including detailed experimental methodology, procedures and preliminary experimental energy savings results. The experiments establish that the LAHU can reduce annual heating by over 30% and can reduce heat recovery pump power by over 50% for this typical laboratory building.Copyright © 2005 by ASME

This paper describes a study that involves commissioning of a full-size dual-duct constant volume (DDCV) system, which serves a four-story office and classroom building with a gross floor area of 6,317 m 2 (68,000 ft 2 ) in a university campus. In early 90s, a variable speed drive (VSD) was installed as a retrofit process. The fan has been operated under constant low speed of 50Hz to limit airflow. The total airflow rate was 22.8 m 3 /s (48,300 ft 3 /min) after the retrofit process. During the current commissioning process, fan speed control was changed from the constant low speed to the static pressure control used in dual duct variable air volume systems. The system maintains the minimum static pressure of hot and cold ducts at a set point. Hourly data of thermal energy and fan power consumptions have been collected from the energy management and control system through the Internet to verify savings of the new control scheme. During the data collection, steam valve leakage was detected, which caused energy wastage as well as a thermal comfort problem. Analyses show that the static pressure control scheme and the steam valve shut-off during summer incur substantial energy savings as well as improve thermal comfort. Additionally, throughout the analyses, it was determined that the system operation can be optimized by resetting cold and hot deck temperature with the pressure control operation of the VSD in the DDCV system.