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Energikartläggning och driftoptimering genom behovsstyrning i befintlig fastighet
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
2014 (Swedish)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesisAlternative title
Energy audit and operational optimization through demand control in existing building (English)
Abstract [en]

Energy supply in Sweden year 2011 amounted to 577 TWh. The final energy consumption for industrial, residential and service was 379 TWh. Sweden has energy policy goals to reduce energy use in buildings. One of these goals is to reduce the energy use by 20 % in 2020 compared to the year 1995. An important step to achieve this goal is to target energy efficiency measures in existing buildings. There are also financial incentives to implement energy efficiency measures due to the fact that the cost of energy represents 30-40% of a buildings maintenance costs. In general, up to 20 % of the energy consumption can be reduced without major reconstruction.

In this master thesis project presented here, an energy audit was performed and energy efficiency measures was proposed for an existing building located at Järfälla, Stockholm. The property belongs to SAAB - Defence and Security. They have an internal target to reduce energy use in their buildings with 50 % by 2015 compared to 2009.

The work of this master thesis project was limited to a building locally termed hus A. This part of the property is the oldest and was built in 1968, but has expanded gradually to the year 1977. Hus A contains of offices, a production hall, laboratories and storage areas. The energy audit showed that the electricity use is far greater in hus A, compared to the an average office and administration building. This is mainly due to production processes. A breakdown of the highest electricity consumers are:

  • Industrial processes – 61.9 kWh/m2/year
  • Lighting – 35.7 kWh/m2/year
  • Fans – 33.2 kWh/m2/year
  • Refrigeration – 21.8 kWh/m2/year
  • Compressed air – 18.9 kWh/m2/year
  • Computer units – 7.8 kWh/m2/year
  • Frequency converters – 4.4 kWh/m2/year

Waste heat from industrial processes, primarily from the production hall leads to high cooling demand to maintain good thermal comfort. Limitations in operation control of the buildings HVAC (Heating, Cooling and Air-conditioning) systems causes high heating and cooling demand and hence the buildings thermal mass is not properly utilized.

Energy saving measures was mainly focused on increasing the controlling capability of HVAC systems. By implementing the energy efficiency measures presented in this master thesis report, building thermal mass will be more efficiently utilized. In addition, end use of electricity, heat and cooling will be reduced. In total, seven energy-saving measures proposed.  One measure is implemented to prevent heating and cooling at the same time. A brief description of the energy efficiency measures and the expected result is found below.

  1. Adjust set point for TAFA301 Energy saving: 94.0 MWh/yearPayback time: 0 year
  2. Establish time schedule for compressed air systemEnergy saving: 110.8 MWh/yearPayback time: 2.5 months
  3. Demand controlled temperature set point to heating systemEnergy saving: 167.0 MWh/yearPayback time: 3.5 months
  4. Demand control of airflow in the production hallEnergy saving: 155,5 MWh/yearPayback time: 2 years and 10 months
  5. Establish time schedule for frequency invertersEnergy saving: 104.0 MWh/yearPayback time: 3 years and 2 months
  6. Radiator thermostats to the first part of the production hall Energy saving: 6.5 MWh/yearPayback time: 5 years and 2 months
  7. Demand control of airflow in conference roomsEnergy saving: 11.0 MWh/yearPayback time: 12 years and 2 months
Place, publisher, year, edition, pages
2014. , 90 p.
Keyword [en]
energy audit, operational optimization, demand control, energy efficiency, existing building, energy-saving measures
Keyword [sv]
energikartläggning, driftoptimering, behovsstyrning, energieffektivisering, befintlig byggnad, energibesparande åtgärder
National Category
Energy Engineering
URN: urn:nbn:se:kth:diva-152530OAI: diva2:750212
Subject / course
Energy Technology
Educational program
Master of Science in Engineering - Mechanical Engineering
2014-06-03, Saab, Nettovägen 6, Järfälla, 15:30 (Swedish)
Available from: 2014-10-21 Created: 2014-09-26 Last updated: 2014-10-21Bibliographically approved

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