![Table 7 Fossil CO2 emission factors for fuels and electricity [37, 38].](/figures/table-7-fossil-co2-emission-factors-for-fuels-and-1q6to2mv.webp)
![Table 2 Roof area, U-values and UA-values for different building categories in Linköping. Mh indicates multidwelling buildings [14, 35].](/figures/table-2-roof-area-u-values-and-ua-values-for-different-854b7h1i.webp)
Q2. What future works have the authors mentioned in the paper "Energy conservation measures in buildings heated by district heating - a local energy system perspective" ?
However, with a changed pricing system for DH and when consider that attic insulation has the possibility to postpone future investments in peak load DH plants and back-up DH plants this measure can be profitable. For the residences there is potential for reduced energy costs but this has to be evaluated on a case by case basis. From an environmental point of view implementing ECMs will decrease the energy demand as well as the emissions of CO2, especially when the electricity use can be reduced.
Q3. What are the three ECMs that are included in this study?
Three ECMs are included in this study: 1) heat load control; 2) attic insulation; and 3) electricity savings due to reducing the electricity use of the residences by changing to new appliances, for example changing to new refrigerators and freezers and to lowenergy lamps.
Q4. What measures can be used to reduce the use of electricity?
Use of electricity can be reduced by replacing household appliances and the measures included in this study are: 1) switching from incandescent lamps to low-energy lamps and 2) investments in a new refrigerator and freezer.
Q5. What is the percentage of the residential sector in the linköping area?
In the Linköping area the residential sector accounts for about 50% of TVAB’s total DH sales, most of which is distributed to multi-dwelling buildings (75%).
Q6. What is included in the economic performance of the residences?
Included in the economic performance of the residences are the annual capital costs for the ECMs as well as the altered energy costs due to changed energy usage.
Q7. What is the effect of ECMs on the local DH supplier?
In Sweden, where DH is well established as the supply for space heating, a change in heating demand can have great effect on the local DH supplier.
Q8. What is the economic effect of the heat load control measure for the multi-dwelling buildings?
by changing heating source from electricity to DH by a reduction of the surplus heat from household appliances the energy costs can be reduced for the multi-dwelling buildings.
Q9. What is the effect of ECMs on the heating system of a building?
An outcome of implementing ECMs is that the heating system of the building will be affected to a great extent, either by a change in the heating system; from for example oil boilers or resistance heaters to district heating (DH) or heat pumps, or by reducing the heat demand.
Q10. What are the main effects of introducing ECMs in the residential sector?
In addition, introducing ECMs in the residential sector will also affect the residents financially in the form of investment costs and changed energy costs.
Q11. What is the effect of the ECMs on multi-dwelling buildings?
Since the majority of DH sales to the residential sector are to the multi-dwelling buildings, the effect of the ECMs has only been studied on multi-dwelling buildings.
Q12. What is the economic impact of the attic insulation measure?
The attic insulation measure has on the other hand the potential to reduce the operation of oil plants more than the heat load control.
Q13. What is the economic performance of the residences?
The economic performance of the residences includes the annual capital costs for the ECMs as well as the altered energy costs due to changed energy usage.
Q14. What is the effect of the attic insulation measure on the DH load?
As can be seen in the figure the attic insulation measure affects the DH load duration curve mainly during the peak heat loads, which represents the winter months, since the temperature difference between indoor and outdoor (∆T) peaks during the winter period.
Q15. What is the cost of switching from incandescent lamps to low-energy lamps?
No investment cost for switching from incandescent lamps to low-energy lamps is included since the incandescent lamps will be phased out in a step-wise process by 2013 according to an EU directive [34] and hence the incandescent lamps must be replaced in any event.
Q16. What is the potential for reducing energy use in buildings?
When implementing energy conservation measures (ECMs) in buildings, for example adding insulation, changing heating system or replacing windows, the potential for decreasing energy use can be substantial.
Q17. What is the effect of attic insulation on the DH supplier?
For instance, attic insulation has a specific heat load profile similar to other insulation measures; hence the effect of attic insulation for the DH supplier can be considered the same as for other insulation measures.