Multizone modeling refers to analysis techniques that use a simplified, zonal representation of a building to study building airflows, pressure differences, and contaminant transport. Each zone is assumed to have uniform temperature, pressure, and contaminant concentrations. Zones typically represent individual rooms but can be entire levels depending on the building layout and the goals of the modeling. Zones are connected through flow paths represented mathematically by pressure-flow relationships. This article describes CONTAMW [Dols et al. 2000], a multizone modeling tool.
An intervention study was performed in a mechanically ventilated office building in which there were severe indoor climate complaints among the occupants. In one part of the building a new heating and ventilation strategy was implemented by renovating the HVAC system, and a carpet was replaced with a low-emitting vinyl floor material; the other part of the building was kept unchanged, serving as a control. A comprehensive indoor climate investigation was performed before and after the intervention.
Carbon dioxide (CO)-based demand controlled ventilation (DCV) is increasingly used to modulate outside air ventilation based on real-time occupancy. Its use could potentially become as common as thermostatic control is today. This article summarizes the current state of the art in CO 2 -based ventilation control including a brief discussion of the technology used, its reliability and how it is best applied. Like any control approach, the success of a C02-based DCV application is dependent on how it is engineered and installed.
A three-dimensional numerical model is used for a turbulent buoyant jet. The standard k-E model has been modified to focus on the buoyancy-production term. The usual and modified buoyancy production coefficients are used for comparisons with experimental data reported in the literature. Imported numerical results are obtained with the modified coefficient for the stack-exit velocities and temperatures. The effects of these parameters on flow characteristics are discussed.
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