Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [119]-122).

Thesis (Ph. D.)--University of Washington, 1990. / Vita. Includes bibliographical references (leaves [155]-163).

Concerns have been raised over the use of plastic skylights as smoke vents in large single story buildings. The plastic skylights provide natural light to the building. There has been an assumption that these plastic panels will melt and provide smoke and heat venting during a fire. The plastics commonly used in New Zealand, polyvinyl chloride (PVC), polycarbonate, acrylic and glass fibre-reinforced polyester (GRP) have been tested in small scale experiments to further the understanding of the behaviour of the materials at elevated temperatures. The behaviour of particular interest is the effectiveness of the skylight as a vent for hot buoyant gases. Small scale experiments have been conducted to find the mass flow rate of an unobstructed vent. Experiments have then been carried out on samples of the four skylight materials for a range of exposure temperatures and times. The mass flow has been measured for the deformed sample and compared to the unobstructed flow. The results of the small scale experiments have been analysed and an empirical relationship has been developed for the PVC and polycarbonate material. The acrylic behaviour does not provide enough data to include it in the empirical relationship. The GRP failed to melt and was therefore also excluded from the empirical relationship. A model has been developed to demonstrate the use of the empirical relationship. The model compares four cases, the vents always open, the vents always closed, the vents opening at a single value and the area when calculated using the empirical relationship.

Air is removed from residential buildings for different reasons such as heat, odor, or moisture removal. The air is usually removed with exhaust fans connected to duct work that lead outside the building. At the interface between the ducting and the ambient, there are vent caps that are used to allow air to flow out the building but not into it. These vent caps can significantly contribute to the pressure that the exhaust fan must overcome to remove air from the building, which means the exhaust fan must consume more energy to run. Unfortunately, vent cap performances are not currently evaluated because there is no establish method to test them. For this reason the objective of this research was to develop a vent cap performance evaluation method that may be used for a variety of vent cap types, designs, and sizes. The evaluation method was then implemented to determine the variance among vent cap designs, determine the evaluation method's repeatability, and to create a method to estimate the vent cap's performance at a specific air flow rate. An air flow chamber with an extension arm was used to test the vent caps. The extension arm is U-shaped to allow the adjustment to the three different orientations that are needed by the three vent cap types. The extension arm also has static pressure taps to measure the pressure drop across the vent cap. The pressure drop was also used to calculate a nondimensional parameter known as a loss coefficient to facilitate performance comparison. From this research it was concluded that the evaluation method can be implemented on the three vent cap types and a variety of designs and sizes. The repeatability of the evaluation method was confirmed by comparing two trials for two different products. The evaluation method was used to confirm that the variation in the products is significantly larger than the uncertainty in the measurements, which were 0.0077 in. w.c. for the pressure loss and 0.06 in the loss coefficient. It was also shown that the loss coefficients can be used to estimate the vent caps' pressure drop at high air flow rates.

No description available.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 131-141).

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 82-126).

Graduation date: 1997 / Best scan available for figures. Original figures are black and white photocopies.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 117-157).

No description available.