CO2 emissions reduction potential from space and water heating in the Hungarian tertiary buildings

The tertiary sector, covering the public and commercial sector, is responsible for 17% of direct CO2 emissions in Hungary (ODYSSEE NMS, 2007). If the CO2 emissions from use of district heat and electricity are included, this figure amounts to 20% of the Hungarian CO2 emissions (ODYSSEE NMS, 2007). At the same time IPCC Fourth Assessment report shows that about one third of the world's buildings' CO2 baseline emissions can be achieved at negative costs by 2020 (Levine et al, 2007). Although several studies have been presented on mitigation potential in the residential sector, studies focusing on tertiary sector are rather limited in number and scope. This paper describes an ongoing project which examines the mitigation potential from space and water heating in the Hungarian tertiary buildings and summarizes its results for the public buildings. Public buildings are a part of the tertiary sector, which are most relevant for the current needs of policy design. The project relies on a bottom-up approach of determination of mitigation potential. The different abatement options are selected from a set of currently commercially available technologies applicable to Hungarian context, assessed on their CO 2 mitigation potential and cost-effectiveness. The options include high performance building envelope components, heat controls and efficient space heating technologies and reduction of demand for hot water for existing buildings and passive house standard for new buildings. The options are assessed in a framework distinguishing several building types based on size of the building, their age and architecture. The preliminary results of the study show that the most cost-effective abatement options in the Hungarian public buildings are reduction of demand for water heating through switching off recirculation when the buildings are unoccupied, and temperature management through installation of heat controls followed by improving the thermal building envelope. The application of passive house standard to new construction offers the largest mitigation potential. Significant part of the total potential can be achieved at zero costs.