This project is mainly focused on the improving and design of the ventilation system of two rooms at different levels of a gym (Friskis and Svettis in Gävle, Sweden) to reduce the  concentration to never be higher than 1000 ppm. For this purpose, several field measurements were performed in different locations and situations. Two main measurements were necessary. On one hand, the  level in different parts of the rooms during different activities. On the other hand, the air flow through the inlet and outlet ducts of the ventilation system. It was also important to take into account the indoor temperature and humidity. These measurements were enough to analyze the failures of the system and to recognize the worst points of each room. Comparing both rooms, the necessity of changing the ventilation system in one of these rooms was much higher, due to there were measured  values up to 3000 ppm during a typical day in the gym. With this information the consequences of high CO2 levels in human people were analyzed. Among various ventilation systems, displacement ventilation system was proposed as the new design. Theoretical calculations were made to reach to the value of 31.8  in the air change rate (ACH), which was the necessary value for the new design to keep the carbon dioxide level under 1000 ppm.

Pig production in Malawi and in most of the developing countries is shifting increasingly from pasture or dirt lot to total confinement with improved housing facilities. Keeping pig level temperatures within the comfort zone in hot weather is a common problem in naturally ventilated intensive pig buildings. Automatically controlled natural ventilation (ACNV) has proved to be effective in reducing the problem of heat build up in pig houses and is becoming very popular. However, a method for reducing summer temperatures at animal level in non-automated naturally ventilated intensive pig buildings has not been developed. An attempt was made to develop a natural ventilation system which would maximise the cooling effect of wind at animal level by manual control in buildings suitable for the Tropics. The research project was conducted in three stages: (1) air flow pattern studies, using 1:20 scale two-dimensional models, (2) wind tunnel testing, using three-dimensional, 1:20 scale models with simulated pigs, and (3) validation of results from the wind tunnel studies made with a 1:4 scale model, put out in the field. Air deflectors were used as a means of increasing the effect of wind on the ventilation pattern in the models. Monopitch, duopitch and offest gable models were tested in the water table, and monopitch models were tested in the wind tunnel. The use of air deflectors in monopitch and offset gable models showed a marked increase in airflow towards the animal zone area and a reduction in the difference between the surface temperature of the model pigs and the outside air temperatures. The deflectors improved the performance of the models by about 10% with the front orientation and about 20% with the rear orientation. In the duopitch model an increase in the roof overhang improved flow circulation on the leeward side. The use of air deflectors also improved flow circulation on the leeward side. The wind speed and air temperature at the experimental site for the 1:4 scale model were used to validate the results from the wind tunnel tests. The measured temperature values showed similar response curves to the predicted values. Temperature differentials increased with an increase in the angle of the deflector.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Currently, deficient ventilation systems are a frequently observed problem in mining. Such deficient ventilation systems lead to the recirculation of stale air or air with toxic gases. This translates into an increase in the costs of ventilation and electrical consumption for the mining organizations as conventional and practical solutions simply include options such as buying a greater number of fans. Moreover, this problem also exposes the mine workers to an unsafe work environment with unfavorable conditions that could end in minor, incapacitating, or fatal accidents. Therefore, this research seeks to optimize ventilation systems by introducing the Ventsim software tool to develop efficient coverage, addressing, flow, circuit or network characterization, and air balancing in conjunction with avoiding the stagnation of toxic gases in underground work. The primary result of the proposed model’s application in this study was the reduction in ventilation costs related to electricity consumption.

This Master Studies Thesis of Quality in Process Technology deals with Process Improvement. The ventilation system of University building is dealt as a Process and is looked for improvements. The ventialtion system for two computer rooms is studied and analyzed for the variaitons in the operating conditions.

Being located in subtropical climates, the cooling energy accounts for a huge percentage of the total power consumption, and has become the major cause for power shortages. Therefore, building energy conservation strategies has become the major remedy to tackle this problem. In this study, the building energy performance certificate evaluation system has been established, in referencing the European communities systems, while integrating the financial and consumers factors to establish the building labeling system in Taiwan.

I detta examensarbete undersöktes möjligheten att installera värmeåtervinningssystem för ett flerfamiljehus i Hovgården som ligger en bit utanför Borlänge. I rapporten redovisas två olika sätt för energibesparingar som är aktuella för att ersätta borttagning av oljepannan som används i huset i dag. En rad svårigheter dök upp under undersökningen för installation av nytt värmesystem. Lämpliga lösningar kunde hittas efter mycket analys. Syftet med rapporten var att undersöka möjligheten och lönsamheten för installation av något av följande system; FVP eller VBX-modul som kan återvinna värme ur frånluften. Undersökningen visade att varken VBX eller FVP kan ersätta oljepannans värmeavgivning på ett tillfredsställande sätt. Med VBX ökas COP från 2,8 till 3,11 vilket leder till 17 MWh/år elbesparing. Däremot FVP kan försörja huset med 59 MWh/år men kan inte täcka effektbehovet för gården under kallaste dagarna. Resultatet blev att de båda undersökta systemen inte har möjlighet att ersätta oljeeldning. / In this thesis, we have studied a building located in Hovgården in Borlänge. The report investigates two energy saving installations that can help to reduce the amount of oil used today in the house. The purpose of the report was to examine the possibilities and viability of exhaust heat pump (FVP) and VBX module that can recover heat from the exhaust air. The investigation showed that neither VBX nor FVP can replace the oil-fired boiler in an acceptable way. With VBX the COP of the existing heat pump is increased from 2.8 to 3.11 leading to 17 MWh/year electricity saving. However FVP can recycle 59 MWh/year from the exhaust air but still cannot cover the power demand of the building during the coldest days. The result was that the two investigated systems are not able to replace oil heating.

Energy saving is a highly concerned topic in the developing countries. To achieve a desirable living and working condition for inhabitants while consuming minimum amount of energy, more and more efforts, new technologies are developed and invested in the different industries by countries. It has been discussed that energy use in the building sectors is intensive and has the largest share in the total energy supply. Therefore, a growing number of companies and institutions are either required or voluntary to take energy efficiency measures once a year or more to identify current energy use, as well as the opportunities for energy efficiency improvement. One of the energy efficiency measures is energy audit. This report is aiming at pinpointing the current energy consumption for a joint ventilation system used by five premises in downtown Gävle, Sweden. The building company is planning a renovation for the ventilation system, including a cut down of energy supply while improving thermal comfort by providing adequate ventilation. The main object area is a restaurant, which consumes most energy supply. During the measurements, three sets of equipment (TSI VelociCalc plus, SWEMA FLOW 230 and TSI-AccuBALANCE) were used to collect air flow and temperature data. The results indicate that the current energy use for the joint ventilation system during a year is around 50438 kWh, using recommended ventilation rates; while it can be reduced to 34737 kWh. For the restaurant, the required ventilation rate is 1204 l/s to provide fresh air constantly if it is over 150 people and give ventilation according the standard: 7 l/s p 0.35 l/s m2. The current ventilation rate is only 312 l/s, thus clearly failing to comply with the standard. One viable method for providing enough ventilation rate and at the same time without wasting energy is to install CO2 detector, which regulates the ventilation rate according to the level of CO2 concentration. The studied shops have instead very high ventilation rates in the current system; though this provides good air quality, the energy is wasted unnecessarily.

The building sector is responsible for 36% of the energy usage and 39 % of all CO2- emissions in European union (EU). Therefore, it is of great interest to investigate how the building sector can become more energy efficient and lower the environmental impact. It is reported that 80-90 % of a building’s total energy usage occurs during the operational phase. The energy usage is mainly due to lightning, technical equipment and the heating, cooling and ventilation system (HVAC-system). During the last century the energy efficiency in lightning developed significantly meaning the energy used in the HVAC-system becomes increasingly significant. As EU aim to increase the energy efficiency and the ratio of renewable energy in the grid, one can assume that the importance of other phases in the HVAC system lifecycle will be increasingly interesting as for example the manufacturing process and material usage which can be evaluated through life cycle assessment (LCA).This thesis presents a comparison between the environmental impacts of a hybrid ventilation (HV) system and a mechanical ventilation system with heat recovery (MVHR) system through a LCA perspective designed for an office building in Lystrup, Denmark. The office building in Lystrup, Denmark was chosen as the HV system is implemented there. The HV system consists of an automated natural ventilation (NV) system and a mechanical exhaust air ventilation (MEV) system. The environmental impact from the NV was provided through environmental products declarations provided by the company dimensioning the NV system. The data was lacking for the MEV system and that system was therefore dimensioned and evaluated through LCA. The mechanical ventilation system chosen for comparison is a mechanical ventilation system with heat recovery (MVHR) decided by the commissioner of the project, Sweco AB. The MVHR system was dimensioned as well. The project was significantly affected by lack of data resulting in many assumptions. The system boundary of the life cycle was set to cradle to grave excluding the energy usage of producing the ventilation components. The assumed lifetime is 25 years. Gabi Education software was used for calculating the LCA results. The impact categories chosen are global warming potential (GWP), ozone depletion potential (ODP), acidification potential (AP), eutrophication potential (EP), photochemical ozone depletion potential (PODP), abiotic depletion potential (ADP) elements and ADP fossil which are used in the EN15804 standard when conducting LCA for construction components. The CML2001-IA 2001 IA method was used for the life cycle impact assessment in the LCA software which also is recommended according to EN15804.The LCA results were compared between the systems and interpreted through contribution analysis were the result was divided in the following categories; Energy usage (use phase), transportation, material usage (including raw material extraction and material processing) and end of life treatment. The two systems score similarly on all environmental impacts categories except for the global warming potential (GWP) and the abiotic depletion potential (ADP) fossil were the MVHR system scores approximately 3 times higher than the HV system. The MVHR system consumes approximately 3 times more energy during the use phase. The contribution analysis showed that the energy usage (use phase) dominated the contribution in almost all environmental impact categories. Further, the environmental impact caused by the material usage was compared between the MVHR - and HV system and the MVHR system scored higher in all categories except ADP elements.The conclusion drawn from this report is that the HV system is better if one looks to GWP and ADP fossil. The HV contributes less to climate change which is an important environmental concern. Further, the energy usage during use phase contributed most to environmental impacts for both the MVHR - and HV system. The environmental impact of the material usage is less for the HV - compared with the MVHR system. / Byggnadssektorn står för 36 % av energianvändningen och 39 % av alla koldioxidutsläpp i Europeiska unionen (EU). Därför är det av stort intresse att undersöka hur byggsektorn kan bli mer energieffektiv och undersöka hur dess miljöpåverkan kan minskas. Det rapporteras att 80–90 % av en byggnads totala energianvändningen inträffar under driftsfasen. Energianvändningen beror främst på belysning och värme-, kyla- och ventilationssystemet (VVS-systemet). Under det sista århundradet har energieffektiviteten gällande belysning förbättrats avsevärt, vilket innebär att betydelsen för energianvändningen till VVS-systemet ökat. Eftersom EU strävar efter att öka energieffektiviteten och mängden förnybar energi i elnätet kan man anta att betydelsen av andra faser i VVS-systemets livscykel kommer att bli allt mer intressant, till exempel tillverkningsprocessen och materialanvändningen vilket kan utvärderas genom livscykelanalys (LCA).   Denna rapport jämför miljöpåverkan från ett hybridventilationssystem (HV) med ett mekaniskt ventilationssystem med värmeåtervinningssystem (FTX-system) ur ett LCA-perspektiv. Studien utförs på kontorsbyggnad i Lystrup, Danmark. Kontorsbyggnaden i Lystrup valdes eftersom ett HV-systemet är implementerat där. HV-systemet består av ett automatiserat naturligt ventilationssystem (NV) och ett mekaniskt frånluftsventilationssystem (F-system). Miljöpåverkan från det NV-systemet tillhandahölls ur miljöproduktdeklarationer (EPD:er) som dimensioneringsföretaget tillhandahöll. Uppgifterna saknades för F-systemet och därför dimensionerades det förhand för att sedan utvärderades genom LCA. Hv-systemet jämfördes mot ett FTX system vilket bestämdes av uppdragsgivaren på företaget Sweco AB. FTX-systemet dimensionerades också förhand för att sedan utvärderas genom LCA. Livscykelns systemgräns sattes till från ”vagga-till-grav” exklusive energianvändningen för att producera ventilationskomponenterna då denna data saknades. Den antagna livslängden för ventilationssystemen är 25 år. LCA programvaran Gabi Education användes för att beräkna LCA resultaten. De miljöpåverkanskategorier som undersökts i den här studien är: global uppvärmningspotentialen, ozonuttunnande potential, försurningspotential, eutrofieringspotential, fotokemisk ozonuttunningspotential, abiotisk utarmningspotential (material) och abiotisk utarmningspotential (fossila bränslekällor) vilka skall användas enligt EN15804-standarden då LCA:er utförs på byggkomponenter. CML2001-IA metoden användes som livscykelkonsekvensbedömningen LCA-programvaran, vilket också rekommenderas enligt EN15804.   LCA-resultaten jämfördes mellan systemen och tolkades genom en bidragsanalys där resultatet delades in i följande kategorier: Energianvändningen (användningsfas), transport, materialanvändning (inklusive råvaruutvinning och materialbearbetning) och slutanvändningsfasen för komponenterna. De två systemen var likvärdiga i de flest miljöpåverkanskategorier utom den globala uppvärmningen potential och abiotiska utarmning potential fossil där FTX-systemet bidrog med ungefär 3 gånger så hög potentiell påverkan än det HV-systemet. FTX-systemet förbrukar ungefär 3 gånger mer energi under användningsfasen. Bidragsanalysen visade att energianvändningen (under användningsfasen) var den dominerade faktorn i nästan alla kategorier av miljöpåverkan. Utöver denna analysen jämfördes miljöpåverkan orsakad av materialanvändningen mellan FTX - och HV-systemet, där FTX-systemet fick högre poäng i alla kategorier utom i abiotiska utarmnings potential (material).   Slutsatsen från den här studien är att det HV-systemet är bättre om man ser till global uppvärmningspotential och abiotisk utarmningspotential fossil. Det HV-system har alltså mindre potential till att bidra till klimatförändringar och mindre potential att utarma fossila bränslekällor. Enligt den här studien är energianvändningen under användningsfasen den faktor som bidrar mest till miljöpåverkanskategorierna för både FTX - och det HV-systemet. Miljöpåverkan orsakad av materialåtgången är mindre för det HV-systemet än FTX systemet.

A comprehensive experimental study has been conducted using Particle Image Velocimetry (PIV) for a wide array of ventilation schemes and mining configurations for the purpose of examining ventilation characteristics in dead end mine headings. Flow behaviors in two basic mining sequences of box and slab cuts for 30 ft and 60 ft deep cuts were studied. The present thesis discusses the effect for various geometric and flow parameters including the variation of inlet flow velocities, entry heights, face zone widths and curtain widths on the flow behavior. The Reynolds number Re considered for this study ranges from 1 105 to 3 106 based on curtain width and exit velocity. The variation of the face zone and the curtain widths considerably affected the flow behavior, resulting in recirculation regions in the face area for critical combinations. Jet spreading angles and virtual origins have been calculated for the different geometries showing that an optimum range of face and curtain widths exists. A detailed discussion employing various scenarios for exhaust ventilation systems has also been made. Full-size measurements and comparison of the experimental data with numerical simulations is presented. Implementation of machine-mounted scrubbers in the blowing system are discussed for different values of the ventilation ratios (Qs/Qin) ranging from 14% to 53%. The scrubber system, typically introduced for dust collection, is also shown to be a useful tool in providing adequate ventilation to the immediate face area.

Air insulation, especially its efficiency, is often underestimated and most often it is recommended as combination of several methods by our experts. It is known that flowing air used to eliminate excessive humidity in lower construction is insignificantly promoted. Already our ancestors in ancient Rome had experience with implementation of air insulations. However, nowadays such design is connected with many doubts and it forces us to use sense, especially knowledge of construction physics. So it urges higher technical precision when designing functional ventilation system. Each building is actually a unique object, with regard to its position and used properties, that is why certain natural conditions must be accepted when designing. It is more complicated and figuratively speaking it can be written in c. 20 equations of twenty unknowns. Other problems arise in unknown coefficients to individual parameters and their effects. From another point of view it is the issue of changing air during the day, passing fronts, annual cycles and all of these in relation to internal environment of the building, materials used in the construction, land properties of rocks, and last but not least, relation to the terrain around the building. Then there are the effects of the building's altitudes etc. In total they are cycles with sine character of dampening and drying. The thesis discusses how to test the functionality of AIR insulations designed for the floor ventilation in historic buildings and follows on from the previously published articles. A flow analysis is being performed on an object of the city of Žirovnice which has been registered in the list of cultural monuments and was built as a brewery in the years 1589-1592 on the site of an older medieval building. This article brings new air-flow element. The aim of the article is to analyse in detail the air flow in a specific floor void with the aid of modern CFD programs and experimental measurements using the ALMEMO