Energy Consumption and CO2 Emission Reduction for Space Heating using SAP in Chilean Dwellings
Authors: Hevia, Angeles
Chile depends by an 80% on fuel imports. Energy prices have been increasing the last years and fuel supply problems have obligated the country to consider cheaper forms of energy such as wood, affecting people’s health. This is not less important taking into account that half of the energy used in a dwelling corresponds to space heating. On the other hand, Chilean Thermal Regulation only considers heat losses caused by thermal envelope elements, without including the ones caused by thermal bridging or air permeability. The use of uncontrolled systems such as burning wood suggests considering the future types of building services that will be implemented in the future in Chilean dwellings bearing in mind new technologies such as renewable energy. However, the UK has implemented the SAP as a methodology that calculates how the above factors affect the energy consumption and CO2 emissions.
The aim of this study is to reduce energy consumption and CO2 emissions caused by space heating implementing the UK SAP methodology in Chilean dwellings across the seven thermal zones of the country. The proposed measures consisted of increasing the airtightness of the dwellings as well as reducing the thermal bridging. Energy efficient building services were considered including among others, air source heat pumps and condensing boilers. Walls were improved taking into account their u-values are quite distant compared to the thermal transmittance observed in roof and floor, as required by the Chilean Thermal Regulation. Bearing in mind the subsidy for solar collectors supported by the Government, these were proposed as the renewable energy used.
Zones 1 and 2 demonstrated energy reductions up to 75% with savings in CO2 emissions up to 21%. These were achieved by adding external insulation and reducing thermal bridging and air permeability. In the case of zones 4 to 7, the maximum energy savings were up to 71% considering CO2 emission reductions of 48%. These were achieved by implementing thermal envelope improvements with solar collectors. Zone 3 was recommended to improve the fabrics in complement to electric wall panel heaters achieving energy reductions of 43% and reducing CO2 emissions by 75%.