Diss. (sammanfattning) Göteborg : Univ. , 2007. / Härtill 4 uppsatser.

The threat of global warming and the uncertainty about future prices have played animportant role in increased focus on energy-related issues worldwide. The world'sgreatest environmental impact is closely related to energy use, as more than 80% of theworld's total energy supply comes from fossil fuels. The world's energy demand hasincreased and the increased energy emerges, this pattern regardless of which sectorindustrial, transportation, residential and service is being viewed. For example, thebuilding sector represents a large share of the global energy use. The majority of energyuse in buildings and homes is used for heating, ventilation and cooling. Thus, thereduction of energy use and especially in building sector is an important task for thefuture and has a major impact on the total energy use and supply.To mitigate or stop the global warming, the European Union (EU) has taken extensivemeasures to reduce energy and environmental impacts as well as a focus on energyefficient systems become increasingly important in the EU, such as the EU's "20-20-20-targets". Equally so, Sweden has set up its own environmental goals to strive for 2020.In order to achieve the EU objectives i.e. 20-20-20 objectives and the goals that Swedenhas set for reducing emissions and saving energy, the energy efficiency of existingbuildings is an important part.This work is an energy-investigation of a property in Gavle with the aim of creating anenergy efficient ventilation system and determines the degree of perceived problemswith drafts and discomfort in some part of the building. This done partly by possibleproposals on efficiency improvement opportunities in the existing system and as well asin a new ventilation system that can provide economic savings for the property ownerand partly by measuring CO2, air velocity, humidity and temperature. To achieve a goodindoor climate and efficient system requires correctly designed and right choice ofventilation systems.In this study has, among other things used scientific journals, reports and books thatcover the field of ventilation systems. The information was searched via the Internet anddatabases such as Science Direct and DIVA. There were also numbers of visits to theproperty in order to get an idea and overview of the work as well as have an overview ofhow the building's heating and ventilation systems are built. To determine the degree ofperceived problems regarding draft and discomfort conducted practical measurementsof temperature, relative humidity and CO2.The results of the work show that the total energy loss in the form of transmission andventilation losses is about 1760 MWh. Ventilation losses represent the largest loss ofenergy and it is account for 83% of the total energy loss. Since the largest energy lossoccurs via ventilation, in case of construction and investment of new efficientventilation units, high potential savings can be made. The work shows that with a newventilation system that has a heat exchanger and an operating time that adapted to thefacility can energy demand be reduced by about 80 percent. The economic savingsusing the present value method is approximately 4.7 million. Furthermore in the newventilation system will be easier to regulate the air flow to a facility, management andhandling of aggregates, because every facility has its own units compared to today'sventilation system where the same facility served by several ventilation units. Generallythe measurement values were made on CO2, RH and temperature during April and Maymonths indicate either in discomfort or poor air quality. During working hours values oftemperature are between 22 and 23 degrees and the CO2 concentration is around 600ppm, which is good and acceptable. The normal CO2 content in the workplace isbetween 500 and 1000 ppm. / Hotet om global uppvärmning och osäkerhet kring framtida priser har spelat en viktigroll av den ökade fokuseringen på energirelaterade frågor i hela världen. Världensstörsta miljöpåverkan är nära besläktad med energianvändningen, eftersom mer än 80 %av världens totala energitillförsel kommer från fossila bränslen. Över hela världen harenergibehovet ökat och i och med den ökade energianvändningen framträder dettamönster oavsett vilken sektor man än tittar på industri, transport, bostads- ochservicesektorn. Till exempel utgör byggsektorn en stor andel av den globalaenergianvändningen. Majoriteten av energianvändning inom bostäder står föruppvärmning, ventilation och kylning. Därför är minskning av energianvändningen ochframför allt i byggnader en viktig uppgift för framtiden och har stor påverkan på dentotala energianvändningen och tillförseln.För att stoppa den globala uppvärmingen har Europeiska Unionen (EU) vidtagitomfattande åtgärder för att minska energi- och miljöpåverkan samt fokus påenergieffektiva system blir allt viktigare inom EU, till exempel EUs ”20-20-20 mål”.Likaså har Sverige satt upp egna miljömål att sträva efter till år 2020. För att uppnå de EUmålen dvs. 20-20-20-målen och de mål som Sverige har satt upp för att minskautsläppen och spara energi är energieffektivisering av existerande byggnader en viktigdel.I det här arbetet görs en energiutredning av en fastighet i Gävle med syftet att skapa ettenergieffektivt ventilationssystem och fastställa graden av upplevda problem som dragoch obehag. Detta gjordes dels genom tänkbara förslag på effektiviseringsmöjligheterpå det befintliga systemet och ett nytt ventilationssystem som kan ge ekonomiskbesparing för hyresvärden och dels genom mätning av CO2, lufthastighet, fukt ochtemperatur. För att nå ett bra inomhusklimat och effektivt system krävs rätt utformatoch rätt val av ventilationssystem.I den här studien har bl. a. använts vetenskapliga tidskrifter, rapporter och böcker somtäcker området ventilationssystem. Informationen söktes via internet och databaser t.ex.Science Direkt och DIVA. Det gjordes också rundvandringar i fastigheten för att få enuppfattning om arbetet och ha överblick om hur byggnadens värme- ochventilationssystem är uppbyggda. För att fastställa graden av upplevda problem somdrag och obehag genomfördes praktiska mätningar av temperatur, relativ luftfuktighetoch CO2.Resultaten från arbetet visar att den totala energiförlusten i form av transmissions- ochventilationsförluster på fastigheten är 1760 MWh. Ventilationsförluster står för denstörsta energiförlusten och är cirka 83 % av den totala energiförlusten. Eftersom störstaenergiförlusten sker via ventilationen, vid en eventuell ombyggnation och investering ide nya effektivare ventilationsaggregaten kan höga besparingspotentialer göras. Arbetetvisar att med ett nytt ventilationssystem som har värmeväxlare samt en drifttid som äranpassad till verksamheten kan energibehovet minskas med ca 80 procent. Denekonomiska besparingen som gjorts med hjälp av nuvärdesmetod är cirka 4,7 miljonerkronor. Dessutom blir det lättare att reglera luftflödet till en verksamhet, sköta ochhantera aggregaten, eftersom varje verksamhet har sitt eget aggregat jämfört meddagens ventilationssystem där en och samma verksamhet betjänas av flera olikaventilationsaggregat.Generellt tyder mätningsvärden som gjordes på CO2, RH och temperatur under april ochmaj månader varken på obehag eller dåligt luftkavalitet. Under arbetstider ligger värdenpå temperatur mellan 22 och 23 grader och CO2-halten är runt 600 ppm som är bra ochacceptabel. Den normala CO2-halten på en arbetsplats ligger mellan 500 och 1000 ppm.

Umeå Energi is a company that will be needed to map the use of energy in their facilities. This thesis is an indication of how this mapping will be like and what the result of the tunnel will show. Together with Umeva, Umeå Energi has a 3,5 kilometres long tunnel where the district heating and district cooling pipes goes. There are also pipes for sewer and drinking water. More thoroughly the thesis shows the energy use of the tunnel and also problem solving for better energy efficient considering ventilation. The quality of air in the tunnel is also analysed where the relative humidity of air is the most studied. The aims of the work are that Umeå Energi can reduce their electrical energy use and that they will get a better knowledge about the air quality in the tunnel. Measurements that where done was for some of the electric devices in the tunnel and there were also previously measurements done for the relative humidity of air, temperature and radon. The payments that has been for the tunnel under 2014 comes from an electrical energy use at 180000 kWh. An investigation about the electricity to the tunnel is done in the thesis and the conclusion is that the real electrical energy use of the tunnel should be 200000 kWh for 2014. The total energy use of the tunnel for 2014 is 460000 kWh, where heating and electricity are included. The analysis of the humidity problem results in that the inlet temperature of air is too high in relation to the air temperature of the tunnel and also that there is an inflow of small water amounts on several parts of the tunnel. Through these factors the relative humidity of air gets more worse and gets as high as 83-84 % in the tunnel. It also comes forward that one of the fans may bring polluted air to the tunnel. If the old fans are replaced by new EC-fans the electrical energy use will reduce. If all the fans would be replaced it gives a positive annuity of 10100 SEK/year but if the fan at Uminova not is replaced it gives a positive annuity of 11200 SEK/year. The payback time of the later choice is approximately 4 years.

The issue of how to ventilate the crawl space of buildings is often debated, since it affects both heat loss and humidity conditions, where the latter is crucial for the onset of mould growth and other microbiological activities. In this moment, experiments are going on in a historical stone church (Hamrånge church, Sweden), where crawl space air is leaking into the church hall, thus affecting heating requirements, air quality and the thermal comfort for visitors. The experiments include long-term field measurements and computer control of ventilation dampers, installed in order to attain a more favourable natural ventilation in the crawl space. The thesis work consists of analysing the above mentioned issues for this unique case.Nowadays this church has a Humidity Controlled Natural Ventilation. It works comparing Absolute Humidity between indoors and outdoors and depending on it, the dampers placed on some of the crawl space vents open or close themselves to let air go through them.The aim of this thesis is to analyse with all the data provided (taken from Hamrånge church) if a crawl space of the church already described is well ventilated or on the contrary it is not well ventilated. This thesis is not a computer simulation one but it is a data treatment one, analysis from data taken from this church will be done. Also it will be focused on the functioning of the control of the ventilation system to check how representative is where the sensor is placed to open and close the dampers. Besides, energy used in heating of one winter with this way to ventilate the crawl space will be compared with other winters when these devices were not used and vents were opened always.The methodology for the analysis will be performed taking advantage of the computer program Excel to be able to manage all the amount of data. A method taken from other authors will be used in order to study the mould growth risk in the crawl space and also some other studies of the variation of the Temperature, Absolute Humidity and Relative Humidity in the crawl space wile dampers are closed or open. Besides a method to analyse wind direction and speed will be implemented.As a result, after implementing all the analysis, this report will be concluded that this new method is well implemented with good results in terms of heating savings compared with other winters. Besides, although mould is a problem, the place where the sensor to open and close the dampers is the best one among the crawl space which is the one where more mould is expected during summer (from June to September), that is the season of the year when more mould and sooner is expected according with the results.

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