Energy consumption in buildings is an important matter for thefuture. In order to reach a sustainable future, both new and oldbuildings must become more energy efficient. This thesisinvestigates how the electricity consumption can be reduced inexisting buildings containing laboratories. This project had twomajor goals. The first goal was to find specific actions toimprove the electricity energy efficiency of The ÅngströmLaboratory, Sweden. The Ångström Laboratory is owned andadministered by the public company Akademiska Hus and rented byUppsala University. The second was to propose a procedure of howto make an arbitrary building containing laboratories moreelectricity efficient. The results indicate that a lot of energycan be saved by optimizing the ventilation of the laboratories. Byreplacing the current ventilation fans with more efficient fans,the potential annual savings were calculated to 0.57 GWh whichcorresponds to 4.2 % of the total annual electricity consumption.By reducing the air-flow in the fume hoods outside working hoursthe electricity consumption in the ventilation system can belowered. The potential savings for this were calculated to 0.31GWh (2.3 %). By modifying the ventilation system of the differentcorridors in such a way that laboratories and offices are placedin opposite ends of the corridor, the operation of ventilationfans can be optimized for laboratories and for officesrepectively. The savings for this were calculated to be 0.07 GWhper year (0.5 %). Another identified opportunity for energysavings in the Ångström building is the replacement of currentlighting fixtures with more efficient systems (typically LED basedsystems). This has the potential to save 0.17 GWh per year.

In Sweden, there are about 0.5 million single-family houses that are heated by electricity alone, and rising electricity costs force the conversion to other heating sources such as heat pumps and wood pellet heating systems. Pellet heating systems for single-family houses are currently a strongly growing market. Future lack of wood fuels is possible even in Sweden, and combining wood pellet heating with solar heating will help to save the bio-fuel resources. The objectives of this thesis are to investigate how the electrically heated single-family houses can be converted to pellet and solar heating systems, and how the annual efficiency and solar gains can be increased in such systems. The possible reduction of CO-emissions by combining pellet heating with solar heating has also been investigated. Systems with pellet stoves (both with and without a water jacket), pellet boilers and solar heating have been simulated. Different system concepts have been compared in order to investigate the most promising solutions. Modifications in system design and control strategies have been carried out in order to increase the system efficiency and the solar gains. Possibilities for increasing the solar gains have been limited to investigation of DHW-units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances). Computer models of pellet stoves, boilers, DHW-units and heat-fed appliances have been developed and the parameters for the models have been identified from measurements on real components. The conformity between the models and the measurements has been checked. The systems with wood pellet stoves have been simulated in three different multi-zone buildings, simulated in detail with heat distribution through door openings between the zones. For the other simulations, either a single-zone house model or a load file has been used. Simulations were carried out for Stockholm, Sweden, but for the simulations with heat-fed machines also for Miami, USA. The foremost result of this thesis is the increased understanding of the dynamic operation of combined pellet and solar heating systems for single-family houses. The results show that electricity savings and annual system efficiency is strongly affected by the system design and the control strategy. Large reductions in pellet consumption are possible by combining pellet boilers with solar heating (a reduction larger than the solar gains if the system is properly designed). In addition, large reductions in carbon monoxide emissions are possible. To achieve these reductions it is required that the hot water production and the connection of the radiator circuit is moved to a well insulated, solar heated buffer store so that the boiler can be turned off during the periods when the solar collectors cover the heating demand. The amount of electricity replaced using systems with pellet stoves is very dependant on the house plan, the system design, if internal doors are open or closed and the comfort requirements. Proper system design and control strategies are crucial to obtain high electricity savings and high comfort with pellet stove systems. The investigated technologies for increasing the solar gains (DHW-units and heat-fed appliances) significantly increase the solar gains, but for the heat-fed appliances the market introduction is difficult due to the limited financial savings and the need for a new heat distribution system. The applications closest to market introduction could be for communal laundries and for use in sunny climates where the dominating part of the heat can be covered by solar heating. The DHW-unit is economical but competes with the internal finned-tube heat exchanger which is the totally dominating technology for hot water preparation in solar combisystems for single-family houses.

Examensarbetet har gått ut på att ta reda på varför en del skolor i Karlstads kommun, använder olika mycket el under kvällar, helger och nätter. Skillnaderna är stora och på grund av det har ett nytt begrepp, kallat elbasnivå, definierats. I princip är elbasnivån den effekt som används under de tider som lokalerna inte nyttjas. Efter genomförd rangordning av elbasnivån med hjälp av en egenutvecklad excelkalkyl, för ett urval på 15 skolor i Karlstads kommun, valdes två av dessa ut för vidare utredning. En skola med låg elbasnivå och en skola med hög elbasnivå valdes. Frödingskolan är den skola som har lägst elbasnivå och valdes att fungera som en referensbyggnad. Den andra skolan är Vålbergsskolan och den valdes då den hade en av de högsta elbasnivåerna i rangordningen. Gemensamt för båda skolorna är att det inte förekommer någon elvärme i fastigheterna. Dessutom finns ingen större årstidsvariation i skolornas elförbrukning. För Frödingskolan uppmättes en elbasnivå på 2,0 W/m2 och för Vålbergskolan 4,6 W/m2, alltså mer än dubbelt så hög för den sistnämnda. Genom studiebesök och omfattande mätningar har elanvändningen i de båda skolorna kunnat kartläggas. Av de resultat som fåtts har olika åtgärder för att sänka elbasnivån tagits fram. Detta har gjorts för båda skolorna även om Frödingskolan hade en låg elbasnivå från början. Det visade sig att även där fanns det åtgärder som kan sänka elbasnivån. Förslag på åtgärder för Frödingskolan:• Policy för avstängning av datorer efter arbetstid ca 1 kW• Avstängning av korridorbelysning på nätter ca 1 kW Förslag på åtgärder för Vålbergsskolan:• Konvertering från golvvärme till radiatorsystem ca 5 kW• Avstängning av frekvensstyrning då ventilationen inte är igång 7,5 kW Om föreslagna åtgärder genomförs kan elbasnivån sänkas till 1,2 W/m2 för Frödingskolan och till 2,0 W/m2 för Vålbergsskolan. För den sistnämnda är detta nästan en halvering av den ursprungliga elbasnivån. / The intention of this final thesis has been to find out why some schools in the municipality of Karlstad (Karlstads Kommun), uses different levels of electric power during evenings, weekends and nights. The differences can vary significantly. Because of this, a new concept, called the electricity base level has been defined. The electric base level is the power used during periods of time when there is no activity in the building. After a ranking of the electricity base level made with a self developed excel-model, for an assortment of 15 schools in Karlstads kommun, two of them were selected for further investigation. One school with low electricity base level and one with high electricity base level were selected. Frödingskolan was the school with the lowest electricity base level and was therefore chosen to serve as a reference-building. The other school is Vålbergsskolan and was chosen though it had one of the highest electricity base levels in the ranking. Common for both schools is that there is no electric heating in either building. Furthermore, no major seasonal variation in the school’s electricity consumptions was found. For Frödingskolan an electricity base level at 2.0 W/m2 (0.19 W/ft2) was measured. For Vålbergsskolan the electricity base level was 4.55 W/m2 (0.42 W/ft2). That is almost twice as high as for the first school. Through field studies and extensive measurements, the electricity usage in the two schools was identified. From the obtained results, several measures to reduce the electricity baseline have been developed. This has been done for both of the schools even though Frödingskolan had a low electricity base level from the beginning. It was to be found that even there a lowering of the electricity base level was possible. Proposed measures for Frödingskolan:• Policy to turn off computers after working-hours, approx. 1 kW.• Turning the corridor lights of at night, approx. 1 kW. Proposed measures for Vålbergsskolan:• Conversion from a radiant floor to a radiator system, approx. 5 kW.• Turn the frequency drivers off when no ventilation are running, approx 7.5 kW If the proposed measures are implemented, the electricity base level can be lowered to 1.2 W/m2 (0.12 W/ft2) for Frödingskolan, and 2.0 W/m2 (0.19 W/ft2) for Vålbergsskolan. For the latter, this is almost the half off the current electricity base level