Optimering av energianvändning i ventilationssystemet för kv. Rektorn,Gävle

Sammanfattning: 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.