Feed-forward Control of Indoor Climate in Office Buildings. A measurement study to indicate internal heat and emissions generated by hymans.
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Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Publicerad
2011
Författare
Isaksson, Christoffer
Johansson, Marcus
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Energy savings is a frequently discussed issue in today’s society and it is desirable to save energy with intelligent solutions that does not cost too much and still are reliable. One way to achieve this in the building sector could be by using smarter control and regulation systems for the indoor climate. The feedback system is a regular solution for control and regulation nowadays, where the investigated parameter is measured and compared with a reference value. An alternative method, called feed-forward, has been evaluated and discussed in this master thesis. The idea of the feed-forward system is to predict the forthcoming indoor climate, to prevent a change before it occurs. This is preferably done by using small measurable variations from existing sensors in the room such as thermometers, carbon dioxide sensors, relative humidity sensors and presence sensors. The aim of this thesis is to find a way to predict a forthcoming increase of the internal heat load, caused by people entering an office room. To find the most suitable parameter or a combination between them for predicting this, a number of tests measuring the mentioned parameters have been performed. The tests were performed at a very flexible test room, in an HVAC-point of view, at Building Services Engineering’s test facility at Chalmers University of Technology. Due to the limitation of the thesis, to only consider internal heat generated by humans, presence is a crucial factor that needs to be examined. Data achieved from the presences sensors does not give enough information, since they only have the ability to tell if someone enters the room and not the number of present people. The response time (dead time) is an important feature of the sensors, which needs to be tested in order to find the parameter that first indicates that people have entered the room. The performed tests show that the carbon dioxide concentration was the fastest parameter to respond compared to the other measured parameters. This means that there is a potential in predicting a temperature raise, caused by internal heat generated by humans, by measuring the carbon dioxide concentration. The idea is to use this prediction to improve the system and thereby raise the thermal indoor climate and at the same time save energy.
Beskrivning
Ämne/nyckelord
Building Futures , Byggnadsteknik , Building Futures , Building engineering