Bachelor Thesis on Energy Optimization without Affecting Comfort!
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April 23, 2015

Bachelor Thesis on Energy Optimization without Affecting Comfort!

The Bachelor Thesis by Adriaan Woonink is available for download (link). Read an interesting thesis evaluating an newly built office building in Sweden with possible savings whilst still providing the best indoor climate and what effect the different energy production methods have on the energy consumption.

Abstract of the Bachelor Thesis.

Despite the fact that the office building in Kvänum is recently build, there are still a lot of possible improvements to optimize the energy use of the building. With more in-depth research about the energy consumption and indoor climate a lot of energy could be saved whilst still maintaining the best possible indoor climate. This means that an evaluation of a building can still be worthwhile even though the building is recently build.

The following results have been calculated with dynamic energy simulation software. A total of 3 different ventilation methods where investigated. These included the combination of constant and demand controlled ventilation systems that are in the current building, a 100% constant ventilation system and a 100% demand controlled ventilation system. A total of 7 simulations were run, to investigate the effect of the different ventilation systems and adaptations to the building.

The multifunctional unit proved to have the highest energy efficiency and lowest annual operating cost. Compared to a common energy production method in Sweden, (air handling unit with district heating and a chiller) 19-26% of the annual energy use and 13-18% of the annual operating cost can be saved. When compared to a more similar energy production method, (air handling unit with a heat pump and a chiller) 1-2,4% of the annual energy use and operating cost can be saved.

The newly build office building already as the best possible indoor climate with a PPD below 6%, but it is not yet optimized from an energy use perspective. Optimizing the temperature set points and introducing night time ventilation (simulation 1a) can save a total of 8.682 kWh which is equal to € 1.129 or 10.387 SEK respectively in operating costs each year. This adaptation could save 7,5% of the annual energy consumption compared to the starting simulation based on the current situation of the building and settings in the building management system (simulation 1). Adapting the building with demand controlled lighting (simulations 2, 4 and 5) could save 3.926 kWh which is equal to € 510 or 4.692 SEK respectively in operating costs each year. This adaptation saves 3,4% of the annual energy consumption compared to the simulation with optimized temperature set points and a minimum of night time ventilation (simulation 1a). Adapting the demand controlled ventilation set points in the building management system (simulations 3 and 4), will save 5.833 kWh which is equal to € 758 or 6.974 SEK respectively each year. This adaptation saves 5% of the annual energy consumption compared to the simulation with optimized temperature set points and a minimum of night time ventilation (simulation 1a).

With the adaptations to the temperature and airflow set points in the building management system and by installing demand controlled lighting, a total of 18.441 kWh which is equal to € 2.397 or 22.052 SEK respectively could be saved annually, compared to the building in its current use, whilst maintaining the best indoor climate. This means that 15,9% of the annual energy consumption can be saved with all of these adaptations combined.

The investigation of the newly build office building in Kvänum showed that for every project it is worthwhile to further investigate the temperature set points both for the occupied periods and the unoccupied periods, the airflow set points, (both for optimized night time ventilation and optimized indoor climate) and investigating the possibility of demand controlled lighting. Investigating the possibility for demand controlled ventilation can downsize the air handling unit by at least one size, which can save on investment cost. Installing the multifunctional unit in cases where there is a need for both heating and cooling at the same time can be more cost effective for the operating costs, compared to when other energy production methods are used, whilst still guaranteeing the best possible indoor climate.

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