Journal of Architectural Engineering

This paper describes the implementation of problem-based instruction program in the integration of architectural design and planning into the architectural engineering curriculum. The program consisted of two components: the use of a problem-based structural design exercise administered to an entire class of upper level architectural and civil engineering students, followed by two design exercises undertaken jointly with architecture and landscape architecture students by a selected group of students from the same class. The effect of participation in the joint design exercises was assessed by means of a final examination question and a questionnaire administered before and after participation in one of the exercises. The results of the assessment indicate that the participants achieved a greater ability to integrate architectural and structural design than the nonparticipants, and that the architectural engineering students have greater ability than civil engineering students to integrate architectural and structural design.

Economizers modulate outside air intake to minimize/eliminate mechanical cooling in air-handling units when outside air enthalpy is lower than the return air enthalpy. A theoretical study is conducted to developed analytical economizer models, to investigate potential energy savings, and to develop a potential energy savings calculation method for dual-duct air-handling unit systems. The study found that economizers decrease cooling energy consumption without heating energy penalties for dual-fan, dual-duct air-handling units. Economizers have significant heating energy penalties for single-fan, dual-duct air-handling units.

The constant-speed fan wastes fan energy and causes excessive noises in nonmakeup-air exhaust systems, where stack-exit velocity decreases proportionally to the laboratory exhaust airflow. A variable-frequency drive (VFD) can maintain the required static pressure at the fume hoods by modulating the fan speed. The VFD reduces the fan power and eliminates the noise problems. A theoretical study has been conducted to investigate the system performance of the constant fan nonmakeup-air exhaust system, the impacts of the VFD, and the optimal VFD control for multiple-stack systems. The results show that the VFD can potentially reduce annual fan energy of the constant-speed fan nonmakeup-air exhaust systems by as much as 51%.

When air distribution in a ventilated room is designed, the outflow velocity from the air supply diffuser is usually treated as uniform. This is true when the duct connections are such that the air enters the diffuser as uniformly as possible with no abrupt changes in direction or velocity. In practical heating, ventilating, and air conditioning systems, space is often limited for duct installation, and a less than optimum connection may have to be used. This technical note presents a study of the influence of diffuser jet characteristics under actual connecting conditions on air distribution in an office room. Measurements and numerical simulation using both uniform and asymmetric diffuser jets as boundary conditions were performed. It was found that the asymmetric flow from an air supply diffuser may have a distinct effect on indoor air distribution.