Traditional air-handling unit (AHU) control systems link the position of the exhaust, recirculation, and outdoor air dampers. Laboratory tests of a variable-air-volume AHU using the traditional damper control approach revealed that outdoor air could enter the AHU through the exhaust air damper. This can negatively impact indoor air quality. This paper examines the conditions that lead to this phenomenon and presents a new control system that can help alleviate the problem. The new control system links only the position of the exhaust and recirculation air dampers.

Ventilation air change rate, local mean age-of-air, and interzonal ventilation air distribution were measured for two single-family homes and eight ventilation systems. A multizone, single-gas, tracer gas decay measurement technique was used. A single-story, slab-on-grade, 1350 ff house was tested in Las ~gas, Nevada, and a two-story, 3192ft2 house with basement was tested in Minneapolis, Minnesota.

A lab house constructed in Pittsburgh has been used as a site for the comparative evaluation of several ventilation systems. The house was built to relatively high performance standards and is representative of the type of house that would be a candidate for a purposely designed ventilation system. The systems installed and tested were (1) supply fan, (2) exhaust fan, (3) heat recovery ventilator, (4) balanced flow fan, and (5) open pipe to the RA plenum.

According to published statistical data, most TB contamination occurs from unknown and unsuspected TB carriers. It can be found in many areas of a health care facility where, based on the building code requirements, the air is not exhausted to the outside but recirculated to other areas of the facility. Although any system exhausting instead of recirculating the air greatly minimizes the risk of contamination, all-exhaust systems are not used because of their increased energy consumption. As an alternative method, recirculated air is HEPA filtered.

This paper provides an overview of inpatient bedroom and support space criteria based on clinical requirements of care. Space requirements are described functionally as they relate to the level of care required or the acuity of the patient. For the purposes of this paper, and in the majority of cases, the level of care provided falls into one of two categories: acute care or intensive care.

Different types of air-conditioning systems, including constant-air-volume air systems, variable-air-volume air systems, fan coil systems, other terminal unit systems, induction units, etc., are described in this paper. Different types of rooms are described. The advantages, disadvantages, and different maintenance needs of a variety of air-conditioning systems, including constant-air-volume air systems, variable air- volume air systems, fan coil systems, terminal unit systems, dual-duct systems, and induction unit systems are reviewed.

A genetic algorithm technique is used to design an HVAC air duct system with minimum life-cycle cost. The approach has the capability to incorporate standard (discrete) duct sizes, variable time-of-day operating conditions and variable time-of-day utility rates. An example is used to illustrate these capabilities and results are compared to those obtained using weighted average flow rates and utility rates to show the life-cycle cost savings possible using this genetic algorithm methodology.

Part I of this paper discussed the theoretical considerations of creating a nonlinear black box model. In P art II, the constraints on the nonlinear model imposed by the application are discussed followed by presentation of the model structure, training method, input selection, and input transformation. The test results of applying the proposed model with the selected features to five test buildings are discussed next. One of the test buildings (Zachry Engineering C enter) selected for this study was also used in a previous study as a p art of energy prediction competition (Haber!

A building energy management system (BEMS) generally monitors and manages energy usage in commercial buildings. With the ability to monitor a plant and to recall the collected data at a later time, actual building energy performance can be measured and compared with the expected performance. The comparison will help in detecting possible abnormalities with the building energy usage and in identifying opportunities to optimize the building energy performance. In order to predict expected building energy performance, a reasonably accurate building energy model is needed.