Health care facilities, offices, as well as workshops and other commercial occupancies, require ventilation and air conditioning for thermal comfort and removal of contaminants and other pollutions. A good design of ventilation and air conditioning provides a healthy and comfortable environment for patients, workers, and visitors. The increasing developments of computational fluid dynamics (CFD) in the recent years have opened the possibilities of low-cost yet effective method for improving HVAC systems in design phase, with less experiment required. This work presents numerical simulations of thermal comfort and contaminant removal for two typical working spaces where these factors are critical: a hospital operating room with various configurations of inlet and outlet arrangements, and an office with two cases of air distribution systems: underfloor and overhead, also with alternative cases. The 2-D simulation approach was employed. Temperature, relative humidity, contaminant concentration, thermal sensation, predicted mean vote (PMV), and contaminant removal factor were computed and used for assessing thermal comfort and contaminant removal characteristics of the office room and operating room. The result shows good agreements with experimental data taken from related literature.

Ziel dieser Arbeit ist die phänomenologische Untersuchung der Feuchteempfindlichkeit der elektrischen Eigenschaften dünner Polymerschichten. Diese Untersuchungen stellen gleichzeitig Vorarbeiten zur Entwicklung von Prototypen von zwei polymeren Dünnschicht-Feuchtesensoren dar, die sich durch die spezielle Auswahl der feuchtesensitiven Materialien jeweils durch eine besondere Eigenschaft gegenüber kommerziellen Massenprodukten auszeichnen. Ziel der Entwicklungsarbeiten für den ersten Prototypen war die Konstruktion eines schnellen Feuchtesensors, der plötzliche und sprunghafte Feuchteänderungen in der umgebenden Atmosphäre möglichst rasch detektieren kann. Dafür wurden dünne Schichten von Poly-DADMAC auf Interdigitalstrukturen aufgebracht, die einen möglichst direkten Kontakt zwischen feuchtesensitiver Schicht und umgebender, feuchter Atmosphäre gewährleisten. Als Messgrößen dienten die Wechselstromgrößen Widerstand und Kapazität der Schichten. Die Feuchtekennlinien der Schichten zeigen gute Konstanz und hohe Reproduzierbarkeit. Der Widerstand der Schichten ändert sich durch den Einfluss von Feuchte je nach Schichtdicke um 3 bis 5 Größenordnungen und eignet sich als Messgröße für die Feuchtigkeit im gesamten Feuchtebereich. Die Hysterese der Filme konnte auf kleiner als 2,5% r.F. bestimmt werden, die Reproduzierbarkeit auf besser als 1% r.F. Die Ansprechzeit der Schichten lässt sich schichtdickenabhängig zu 1 bis 10 Sekunden bestimmen. Hierbei zeigen besonders die dünnen Schichten kurze Ansprechzeiten. Zielstellung für den zweiten Feuchtesensor war die Entwicklung eines Prototypen, dessen sensitive Schicht sich biostatisch und biozid verhält, so dass er in biotischen Umgebungen eingesetzt werden kann. Es wurden fünf Polysulfobetaine synthetisiert, deren Biozidität und Biostatik mit dem Kontakttest nach Rönnpagel, dem ISO846-Test und Abbautests bestimmt wurde. Zwei Polymere – Poly-DMMAAPS (BT2) und Poly-[MSA-Styren-Sulfobetain] (BT5) – erwiesen sich als ausreichend biozid und biostatisch. Schichten dieser Polymere wurden auf Interdigitalstrukturen aufgezogen, anschließend wurden die Kennlinien dieser Proben aufgenommen. Die Messwerte zeigen für beide Polymere gute Konstanz und eine hohe Reproduzierbarkeit. BT2-Proben sind zwischen 20% und 80% r.F. besonders empfindlich und zeigen über einen Monat keine Langzeitdrift. Vernetzte Proben zeigen bis 50°C keinen temperaturbedingten Abfall der Feuchteempfindlichkeit. Der Einsatz vernetzter BT5-Schichten als kapazitiver Feuchtesensor ist bis etwa 70°C möglich, die Schichten sind selbst nach Lagerung im Hochvakuum und mehrfacher Betauung stabil. Damit liegen zwei funktionsfähige Prototypen von Feuchtesensoren vor, für die die meisten Kennwerte denen von vergleichbaren kommerziellen Feuchtesensoren entsprechen. Gleichzeitig zeichnen sie sich aber durch eine sehr niedrige Ansprechzeit bzw. eine ausreichende Lebensdauer unter biotischen Bedingungen aus. / The topic of this work is the phenomenological investigation of the humidity sensitivity of the electrical properties of thin polymer films. These investigations also act as preparatory work for the development of prototypes of two polymer thin film humidity sensors, which by the choice of the humidity sensitive materials stand out by one special property each compared with commercial mass products. The aim of the development work for the first prototype was the construction of a fast humidity sensor, which can rapidly detect sudden and erratic humidity changes in the surrounding atmosphere. Thin films of poly-DADMAC were prepared on interdigitated structures that allow for undisturbed contact between the sensitive layer and the surrounding humid atmosphere. Measured variables were the ac resistance and capacity of the films. The humidity characteristics of the films show good stability and high reproducibility. Under the influence of humidity the resistance of the films changes by 3 to 5 orders of magnitude, depending on the film thickness, and is suitable to measure the humidity in the entire humidity range. The hysteresis of the films is lower than 2.5% r.h., the reproducibility better than 1% r.h. The response time of the layers can be determined to 1 to 10 seconds, depending on their thickness. The thin films, specifically, show very short response times. The aim for the second humidity sensor was the development of a prototype, where the sensitive film is biostatic and biocide, so that it can be used to measure the humidity in biotic environments. Five polysulfobetaines were synthesized and their biocidity and biostatics were tested with the contact test according to Rönnpagel, the ISO846 test and degradation tests. Two of the polymers - poly-DMMAAPS (BT2) and poly-[MSA-styrene-sulfobetaine] (BT5) - showed sufficient biocidity and biostatics. Films of these polymers were prepared on interdigitated structures, then their humidity characteristics were recorded. The measured values show good stability and high reproducibility for both polymers. Samples of BT2 are highly sensitive between 20% and 80% r.h. and show no long-term drift after one month. Cross-linked samples show no decrease of the humidity sensitivity in temperatures up to 50 degrees Celsius. Cross-linked films of BT5 can be used as a capacitive humidity sensor up to 70 degrees Celsius, and the samples are stable even after storage in high vacuum and multiple dew cycles. These two functional prototypes of humidity sensors show characteristic data comparable to those of commercial sensors. However, they stand out, respectively, with a very short response time and a sufficient life time in biotic environments.

Electrostatic charge generation in gas-solid fluidized beds is a significant industrial problem. Associated problems include particle agglomeration and particle wall fouling. In the polymerization industry this may result in "sheets" of fused polymer, due to exothermic reaction causing the melting of the polymer, which can fall off and block the distributor plate disrupting fluidizing gas flow. Additionally, blockage of the catalyst feed or the polymer removal system can take place or the product can become non-uniform. All of these problems require shut-down of the reactor which results in lost production time. While this phenomena has been identified for many years, the mechanisms involved are not well understood, especially wall fouling and the distribution of charge within the bed. Isolation of individual parameters such as hydrodynamics, operating conditions, and material involved is necessary to evaluate how each parameter impacts charge generation during fluidization. In this thesis, the fluidization system consisted of a stainless steel column, two online Faraday cups, and a retractable distributor plate. This system allowed for the simultaneous measurement of charge within different regions of the bed: the entrained fine particles, the particles adhered to the column wall, and the bulk of the bed. Additionally, mass and particle size distributions were measured and images of the layer of particles adhered to the column wall were taken for comparison. This allowed for a charge distribution comparison and evaluation of wall fouling. Three different parameters were investigated: duration of fluidization, column wall material, and relative humidity of fluidizing gas. Fluidization time was studied for 15, 30, 60, 120, 180, and 360 min; relative humidity was investigated for 0%, 20%, 40%, 60%, and 80% relative humidity. Both fluidization time and relative humidity were evaluated at four different fluidization gas velocities, two each in the bubbling and slugging flow regimes. Column wall material was evaluated for a stainless steel and carbon steel column at two gas velocities, one each in the bubbling and slugging flow regimes. Fluidization time was found to influence wall fouling in the bubbling flow regime as the particle layer continued to build as fluidization progressed. In the slugging flow regime, the particle layer developed within 15 minutes of the onset of fluidization. The bubbling flow regime was shown to have a greater capacity for charge generation than the slugging flow regime. This was due to the vigorous mixing in the bubbling flow regime resulting in more particle-particle interactions. Column wall material was shown to influence wall fouling in the slugging flow regime due to the differences in surface roughness of the columns. This was due to the particle-wall contacts resulting in frictional charging which is the predominant charging mechanism in this flow regime. Charge was also impacted in the bubbling flow regime in those particles that were adhered to the column wall. Relative humidity was found to influence wall fouling at the lowest gas velocity tested. However, variations in generation of charge occurred at all fluidization gas velocities tested; the charge-to-mass ratios for the particles adhered to the column wall in the slugging flow regime decreased with high relative humidities. This was due to either the formation of a water film layer on the column wall or instantaneous surface water films on the particles throughout fluidization.

<p>Certification of energy wheel effectiveness by a selected international laboratory for many types and sizes of wheel produced by each manufacturer has proven to be very expensive and has been prone to large uncertainties. This research uses a new, low-cost, transient method to predict the effectiveness using only data obtained from transient measurements.</p><p>In this thesis, an analytical model is presented for predicting the effectiveness of rotating energy wheels using only the characteristics measured on the same non-rotating wheels exposed to a step change in temperature and humidity. A relationship between the step response and the periodic response of an energy wheel is developed using first order linear system design theory. This allows the effectiveness of an energy wheel to be predicted when the characteristics of a step response are known. The effectiveness correlations and uncertainty bounds for sensible and latent effectiveness of energy wheels determined from transient measurements are thus presented.</p><p>The experimental transient testing method and experimental verification of the effectiveness model for several different wheels are also presented in this thesis. The results obtained from the new effectiveness model are shown to agree, within uncertainty bounds, with the results obtained from the standard steady state experimental testing method and numerical simulations.</p>

The main objectives of this thesis are to determine if the addition of an energy wheel in an HVAC system can improve the indoor air relative humidity (RH), and perceived air quality (PAQ), as well as reduce energy consumption. An energy wheel is an air-to-air energy exchanger that transfers heat and moisture between the outdoor air entering and the exhaust air leaving a building. This thesis uses the TRNSYS computer package to model two buildings (an office and a school) in four different cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida and Phoenix, Arizona).<p>The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the buildings. The energy wheel reduces peak RH levels in Tampa, (up to 15% RH), which is a humid climate, but has a smaller effect on the indoor RH in Saskatoon (up to 4% RH) and Phoenix (up to 11% RH), which are dry climates. The energy wheel also reduces the number of people that are dissatisfied with the PAQ within the space by up to 17% in Tampa. <p>The addition of the energy wheel to the HVAC system creates a reduction in the total energy consumed by the HVAC system in Saskatoon, Phoenix and Tampa (2% in each city). There is a significant reduction in the size of the heating equipment in Saskatoon (26%) and in the size of the cooling equipment in Phoenix (18%) and Tampa (17%). A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities, with savings of up to 6%. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ and energy consumption.

Electrostatic charge generation in gas-solid fluidized beds is a significant industrial problem. Associated problems include particle agglomeration and particle wall fouling. In the polymerization industry this may result in "sheets" of fused polymer, due to exothermic reaction causing the melting of the polymer, which can fall off and block the distributor plate disrupting fluidizing gas flow. Additionally, blockage of the catalyst feed or the polymer removal system can take place or the product can become non-uniform. All of these problems require shut-down of the reactor which results in lost production time. While this phenomena has been identified for many years, the mechanisms involved are not well understood, especially wall fouling and the distribution of charge within the bed. Isolation of individual parameters such as hydrodynamics, operating conditions, and material involved is necessary to evaluate how each parameter impacts charge generation during fluidization. In this thesis, the fluidization system consisted of a stainless steel column, two online Faraday cups, and a retractable distributor plate. This system allowed for the simultaneous measurement of charge within different regions of the bed: the entrained fine particles, the particles adhered to the column wall, and the bulk of the bed. Additionally, mass and particle size distributions were measured and images of the layer of particles adhered to the column wall were taken for comparison. This allowed for a charge distribution comparison and evaluation of wall fouling. Three different parameters were investigated: duration of fluidization, column wall material, and relative humidity of fluidizing gas. Fluidization time was studied for 15, 30, 60, 120, 180, and 360 min; relative humidity was investigated for 0%, 20%, 40%, 60%, and 80% relative humidity. Both fluidization time and relative humidity were evaluated at four different fluidization gas velocities, two each in the bubbling and slugging flow regimes. Column wall material was evaluated for a stainless steel and carbon steel column at two gas velocities, one each in the bubbling and slugging flow regimes. Fluidization time was found to influence wall fouling in the bubbling flow regime as the particle layer continued to build as fluidization progressed. In the slugging flow regime, the particle layer developed within 15 minutes of the onset of fluidization. The bubbling flow regime was shown to have a greater capacity for charge generation than the slugging flow regime. This was due to the vigorous mixing in the bubbling flow regime resulting in more particle-particle interactions. Column wall material was shown to influence wall fouling in the slugging flow regime due to the differences in surface roughness of the columns. This was due to the particle-wall contacts resulting in frictional charging which is the predominant charging mechanism in this flow regime. Charge was also impacted in the bubbling flow regime in those particles that were adhered to the column wall. Relative humidity was found to influence wall fouling at the lowest gas velocity tested. However, variations in generation of charge occurred at all fluidization gas velocities tested; the charge-to-mass ratios for the particles adhered to the column wall in the slugging flow regime decreased with high relative humidities. This was due to either the formation of a water film layer on the column wall or instantaneous surface water films on the particles throughout fluidization.

Excess global elemental sulphur (So) production has resulted in a decrease in its price. As a result, many companies, such as Syncrude Canada Ltd., have resorted to above ground storage alternatives. Geochemical reactions in these above ground blocks produce elevated concentrations of H2SO4 (acid). This acid can have potentially deleterious effects on the environment. As such, these blocks will require long-term (500 years) monitoring and maintenance. Presently the So is removed from the product stream, piped in a molten state, and poured over a low permeability liner in thin lifts. As the So cools and undergoes crystal structure change it fractures, creating preferential flow passages which are potentially highly conductive. An understanding of the liquid conductivity (Kl) of the block and knowledge regarding the spatial and temporal distribution of acid (H2SO4) within these blocks is required. In this thesis, gas pumping tests were conducted on an above ground block to determine the gas flow rates within the block and to indirectly determine the Kl of the block. Measurements of the relative humidity (RH) in the block were used to observe changes in stored acid concentrations with time and location. The results of the gas conductivity (Kg) testing showed that the block is anisotropic and is highly conductive in both the horizontal and vertical directions. Cross hole tests appeared to produce the most representative estimates of Kg due to the negation of turbulence that arises in the vicinity of the borehole. The choice of gas used in the analysis had negligible effect on the resulting Kl in contrast to choice of liquid, which resulted in larger variations in Kl. The Kl was a maximum when the liquid was pure water and decreased with increasing acid strength. The geometric mean of the resulting cross hole Kl values was 2 x 10-3 m s-1 (pure water). RH measurements were observed to fluctuate with depth and increased following precipitation. The resulting minimum pH observed within the block occurred at depths of 3 and 7 meters below the surface of the So block and increased with depth. The arithmetic mean pH value based on the daily averaged RH measurements was -1.7.

<p>Certification of energy wheel effectiveness by a selected international laboratory for many types and sizes of wheel produced by each manufacturer has proven to be very expensive and has been prone to large uncertainties. This research uses a new, low-cost, transient method to predict the effectiveness using only data obtained from transient measurements.</p><p>In this thesis, an analytical model is presented for predicting the effectiveness of rotating energy wheels using only the characteristics measured on the same non-rotating wheels exposed to a step change in temperature and humidity. A relationship between the step response and the periodic response of an energy wheel is developed using first order linear system design theory. This allows the effectiveness of an energy wheel to be predicted when the characteristics of a step response are known. The effectiveness correlations and uncertainty bounds for sensible and latent effectiveness of energy wheels determined from transient measurements are thus presented.</p><p>The experimental transient testing method and experimental verification of the effectiveness model for several different wheels are also presented in this thesis. The results obtained from the new effectiveness model are shown to agree, within uncertainty bounds, with the results obtained from the standard steady state experimental testing method and numerical simulations.</p>

The main objectives of this thesis are to determine if the addition of an energy wheel in an HVAC system can improve the indoor air relative humidity (RH), and perceived air quality (PAQ), as well as reduce energy consumption. An energy wheel is an air-to-air energy exchanger that transfers heat and moisture between the outdoor air entering and the exhaust air leaving a building. This thesis uses the TRNSYS computer package to model two buildings (an office and a school) in four different cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida and Phoenix, Arizona).<p>The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the buildings. The energy wheel reduces peak RH levels in Tampa, (up to 15% RH), which is a humid climate, but has a smaller effect on the indoor RH in Saskatoon (up to 4% RH) and Phoenix (up to 11% RH), which are dry climates. The energy wheel also reduces the number of people that are dissatisfied with the PAQ within the space by up to 17% in Tampa. <p>The addition of the energy wheel to the HVAC system creates a reduction in the total energy consumed by the HVAC system in Saskatoon, Phoenix and Tampa (2% in each city). There is a significant reduction in the size of the heating equipment in Saskatoon (26%) and in the size of the cooling equipment in Phoenix (18%) and Tampa (17%). A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities, with savings of up to 6%. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ and energy consumption.

Polyimide thin films have been widely used in microelectronic and Micro-Electro-Mechanical System applications due to their many excellent characteristics including low dielectric constant, easy processing, good step coverage ability, high heat resistance and chemical resistance. This paper presents the design, fabrication and complete characterization of an innovative capacitive relative humidity (RH) microsensor. The double polyimide thin films adopted in this study function as a capacitance sensing layer and a protecting layer of top electrodes respectively. To improve the humidity sensitivity and responding speed, interlacing out-of-plane electrodes are designed in the RH microsensor. The higher sensitivity ( 1.25 pF/¢HRH ), optimized sensing linearity ( 99.968¢H ) , very low hysteresis ( 0.24 ¢HRH ), excellent stability ( 1.36 ¢HRH ) , high accuracy ( ¡Ó 1.12 ¢HRH ) and fast response ( within 1 seconds ) characteristics of the RH microsensor have been demonstrated in this thesis.