À ce jour, cette thèse n’a pas été déposée. L’Université Clermont Auvergne est donc dans l’impossibilité d’en assurer le traitement, la conservation et la diffusion. / To date, this thesis has not been deposited. The Université Clermont Auvergne is therefore unable to ensure its processing, conservation and dissemination.

A method of providing ventilation using impinging jets (IJV) utilizes stratification while delivering air at a high velocity. As a result of this attribute and the simplicity of its terminal construction, IJV offers an advantage over the well-known Displacement Ventilation (DV) system. The corner IJV system was used during this investigation to construct the Computational Fluid Dynamics (CFD) simulation protocol. To verify the suitability of the turbulence model used in the CFD simulation, numerical values derived from several turbulence models were compared to full-scale experiment data. The results of this study demonstrate that turbulent models are the most important factors when using CFD for the study of the velocity field generated by IJVs terminals. A parametric study was conducted after the models were created and verified using the CFD software COMSOL to determine which is the most suitable arrangement for occupants' ventilation and draught avoidance in a square room. Calculations using computational methods were conducted to characterize the rooms' performance under different operating conditions and cross-sections of the air supply terminals. Among the findings of the research is that increasing the cross-section of the supply terminal reduces the sensation of local discomfort, but decreases air velocity speeds. Furthermore, placing the supply terminal on the same side of a room block improves occupant satisfaction, whereas placing the supply terminal on opposite sides enhances ventilation efficiency.

Many airborne diseases such as Coronavirus variants are spread from person to person by indoor air movement. This is of particular concern in healthcare environments such as hospitals. There is a significant body of research that suggests that indoor ventilation strategies such as personalized ventilation systems my help reduce the spread of these viruses. While there are studies related to the efficacy of air movement from personalized ventilation, there are very few studies that explore how best to integrate these systems into the design process for hospital patient rooms. This study focuses on how to integrate personalized ventilation (PV) and displacement ventilation (DPV) systems into patient room design. The aims of this study are to first, develop a procedure using the Choosing By Advantages approach to make design decisions related to the implementation for personalized ventilation and displacement ventilation in private and semi-private patient rooms to prevent cross-infection. Secondly, using this approach, design solutions are proposed for patient room layouts with PV and DPV in different locations. The study proposes the best locations and components of the PV and DPV ventilation air supply and exhaust. Further practical models/simulation rooms are required to test the impact of PV systems on patients' and nurses' daily activities. / Master of Science / Many airborne diseases such as Coronavirus variants are spread from person to person by indoor air movement. This is of particular concern in healthcare environments such as hospitals. New personalized ventilation systems place ventilation air directly at the patient bed and consequently can reduce the spread of these viruses by effectively managing in-room air movement. This study explores how best to make design decisions for the implementation of personalized ventilation systems into hospital patient rooms. Applying this decision-making approach, design solutions are proposed that integrate personalized ventilation with commonly used displacement ventilation in patient rooms.

Natural ventilation is an effective method to save energy required to condition buildings and to improve indoor air quality. Computational fluid dynamics (CFD) was used to model single-sided buoyancy-driven natural ventilation in a single room with a heater and door. The velocity and temperature profiles at the doorway agreed fairly well with published literature that includes Mahajan's experimental [2] and Schaelin et al's numerical studies [1]. The 2D and 3D models predicted the neutral level with a difference of 5.6 % and 0.08 % compared to the experimental results, respectively. Using solutions at the doorway, heat transfer rates were calculated. More realistic situations were studied considering conduction, various ambient conditions, wind speeds, and additional heat sources and furniture in the room. The heat loss through the wall was modeled and the airflow and temperature within the room showed no significant changes despite modeling conduction through the walls. Various ambient temperatures and wind speeds were tested, and the neutral level height and total heat transfer rate through the doorway increased with decreasing ambient temperatures. However, the neutral level did not significantly change as wind speeds varied. Total heat transfer rate at the doorway became positive, that is heat transferred into the room, with wind speed. Lastly, the effect of additional heat sources (mini-refrigerator, monitor and computer) and furniture (bookshelf, desk, chair and box) on airflow and heat transfer in the room was analyzed by comparing with a simple case of a room with a heater. Large velocities and high temperatures were predicted in the vicinity of the heat sources. However, the spatially averaged velocity and temperature did not change significantly despite additional heat sources. The room with furniture was modeled at lower ambient temperature, where the spatially averaged velocities were larger and temperatures were lower than the simple case. The room heated up and reached its thermal comfort level, but the velocities exceeded the maximum acceptable level set by ASHRAE guidelines [8]. Wind was considered simultaneously with the lower temperature, and the room was cooled faster with wind. However, the room was never able to achieve the comfortable level both in velocity and temperature. / Master of Science

Typescript (photocopy). / Digitized by Kansas Correctional Industries

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This thesis investigated thermal comfort for naturally ventilated housing in Iran with special reference to Ilam. An important aim was to establish the neutral temperature and the acceptable range of environmental conditions for Dam people in their houses. The methodology used for this aIm was field studies. These studies were divided into two parts- one in the hot season and the other in the cool season. The results showed a good relationship between neutral temperature and mean indoor temperature and also between outdoor temperature and neutral temperature. The indoor comfort temperature (Tn), which is dependent on outdoor temperature (Tom), could be found from the following equation: Tn = 17.3 + 0.36 Tom The findings of the study revealed that the Ilam people could achieve comfort at higher indoor air temperatures compared with the recommendations by international standards like ISO 7730. The results also showed that passive systems as a main comfort strategy could be applied to housing design in Ilam. By using the results of this study, strategies to minimise housing energy consumption, not only for Ilam but also for other regions, which have similar climates and cultures to Ilam, can be proposed.

Summer brooding often requires some form of air modification in addition to maximizing ventilation rate to prevent animal heat stress and possible death due to hyperthermia. A rockbed thermal storage module was designed and constructed to provide sensibly cooled air for a broiler space under summer brooding conditions. A mathematical model of rockbed thermal storage module was developed to predict performance of the prototype module. Experiments to evaluate the rockbed module under different weather conditions and operating schedules were conducted. The results were presented and compared with the mathematical simulation. A microprocessor control system was designed and assembled to control the ventilation air that would enter a broiler house during warm weather periods. The system was capable of taking temperature samples from thermocouples and then operate a damper arrangement which determined the mixture of outdoor and sensibly cooled air from rockbed thermal storage module. The cost and feasibility of utilizing a rockbed thermal storage module and a microprocessor control ventilation system were discussed. / Graduation date: 1989

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Vid projektering idag ställs konstruktören ofta inför valet att projektera för antingen ventilation med konstanta flöden, eller med variabla flöden. Vidare kan även flödena varieras manuellt eller automatiskt. Det konstruktören måste ta hänsyn till är investeringskostnaden, men även potentiella energi- samt kostnadsbesparingar över tid. Många gånger är det svårt att veta hur energianvändningen påverkas av de olika systemvalen varför det är svårt att välja det mest optimala systemet.Detta arbete undersöker livscykelkostnaden, LCC, med nuvärdeskostnaden på en skola i Uppsala med tre olika system, antingen konstant ventilationsflöde, CAV med timer, manuellt styrd variabel ventilation, VAV, eller automatisk VAV med styrning på temperatur och CO2. Huvudanledningen till det är att skolor består av en mängd olika klassrum och lokaler som inte alltid används under skoltiden, risken finns alltså att skolan överventileras med ett traditionellt CAV. Johansson (2005) visade att VAV mycket väl vara ekonomiskt försvarbart just i skolor varför syftet med detta arbete är att se hur det föreligger i detta aktuella fall, och vilken av lösningarna som är mest ekonomisk.Skolan simuleras med programvaran VIP Energy 2.0.8, ett simuleringsprogram för energibalansberäkning, där de tre olika driftsfallen undersöks och hur energibehovet förändras men varierad ventilationsgrad. Även temperaturerna i klassrummen simuleras och beaktas. Kostnaderna för de olika installationerna presenteras där det visar sig mer avancerade system är betydligt dyrare. Den billigaste lösningen kostar 450 000 kr medan den dyraste kostar 680 000 kr. Vidare diskuteras kalkylräntan, energipris och energiprisförändringarna, och där används två olika kalkylräntor, 5 % och 10 %. Ett Sverigepris på energi presenteras, men även ett Europa-anpassat alternativ där elpriset antas dyrare. Realenergipriset antas öka med 3 % per år.Resultatet visar att de energivinster man gör med de mer avancerade variabla systemen som försvinner de på grund av de dyrare investeringskostnaderna. I vissa fall visar det som däremot att en manuell VAV styrning på ventilationen kan vara ekonomisk försvarbar.Ett problem som dock uppstår med sänkt ventilation under sommarhalvåret är innetemperaturer som överstiger de högstanivåer som Socialstyrelsen satt. / When designing today, the building designer is often faced with the choice of planning for either ventilation with constant flow or variable flow. Furthermore the flows can be varied manually or automatically. The building designer has to take into account the cost of the investment, but also potential energy- and cost savings over time. Many times it is difficult to know how energy is affected by the various systems making it difficult to choose the most optimal system.This work investigates the LCC present value at a school in Uppsala with three different systems, either CAV with timer, manually controlled VAV or automatic VAV with is controlled by temperature and CO2. The main reason is that schools consist of a variety of classrooms and facilities that are not always used during school time, the risk is that schools can be over ventilated with a traditional CAV. Johansson (2005) showed that VAV can be financially feasible in schools why the purpose of this thesis is to see how it is in this current case, and which solution is the most economical.The school is simulated with software VIP Energy 2.0.8 where the three different operating conditions are investigated and how energy changes with varied ventilation rate. The temperatures in the classrooms are also simulated and observed. The costs of the various installations are presented where it appears more advanced systems are significantly more expensive. The cheapest solution costs 450 000 SEK while the most expensive costs 680 000 SEK. Furthermore the thesis also discuss the cost of capital, energy price and energy price changes, and where two different discount rates, 5% and 10%, is used. A Sweden Price on energy is presented, but also a Europe-adapted option where electricity price is predictable more expensive. Real energy prices are expected to increase by 3% per year.The results show that the energy savings due to the more advanced variable systems is marginalized because of the expensive investment costs. In some cases it shows that a manual control of ventilation VAV may be economic considerations.A problem arises, however, with reduced ventilation during the summer months as the temperatures exceeds the maximum levels Socialstyrelsen made.