Famiglietti Jacopo, Toppi Tommaso, Pistocchini Lorenzo, Scoccia Rossano, Motta Mario
Department of Energy, Politecnico di Milano, 20156 Milano, Italy.
Department of Energy, Politecnico di Milano, 20156 Milano, Italy.
Sci Total Environ. 2021 Mar 25;762:144392. doi: 10.1016/j.scitotenv.2020.144392. Epub 2020 Dec 17.
Gas absorption heat pumps represent an alternative to condensing boilers for space heating and domestic hot water production in existing buildings. In particular, they enable fuel saving and the exploitation of renewable energy even in heating systems based on radiators, which require high supply temperature. However, in order to provide useful indications to policymakers, manufacturers, and system designers, a fair comparison of two technologies has to be based, besides the energy consumption and the direct CO eq emissions, also the environmental impact over the entire life cycle. Thus, in this paper, the environmental profiles of a condensing boiler and a gas driven absorption heat pump are compared as competing technologies to provide space heating and domestic hot water in old (constructed before 1980) and not refurbished buildings. The assessment was carried out for three buildings located in three representative European climates, using 1 kWh of thermal energy produced by the two systems as the functional unit. The Ecoinvent 3.6 was used as background database and the EF 3.0 normalization as weighting set method. Uncertainty and sensitivity analysis were also included. The results show that the use phase contributes for more than 97% of the total impact for both the energy systems in the three climate zones. Despite the higher electricity consumption, the gas driven absorption heat pump offered a lower environmental profile compared with the condensing boiler, mainly because of the lower amount of natural gas needed in the use phase. In particular, an average reduction of 27% was found for CO eq, 25% for fossil resource consumption, and 22% for weighting results.
燃气吸收式热泵是现有建筑中用于空间供暖和生活热水生产的冷凝锅炉的替代方案。特别是，即使在基于散热器的供暖系统中，它们也能实现节能并利用可再生能源，而这种系统需要较高的供水温度。然而，为了向政策制定者、制造商和系统设计师提供有用的参考，除了能源消耗和直接的二氧化碳当量排放外，两种技术的公平比较还必须基于整个生命周期的环境影响。因此，在本文中，对冷凝锅炉和燃气驱动吸收式热泵的环境概况进行了比较，它们作为竞争技术，为建于1980年以前且未翻新的旧建筑提供空间供暖和生活热水。评估针对位于三种具有代表性的欧洲气候区的三座建筑进行，以两个系统产生的1千瓦时热能作为功能单元。使用Ecoinvent 3.6作为背景数据库，并采用EF 3.0归一化作为加权集方法。还包括不确定性和敏感性分析。结果表明，在三个气候区中，使用阶段对两种能源系统的总影响贡献均超过97%。尽管燃气驱动吸收式热泵的电力消耗较高，但与冷凝锅炉相比，其环境概况更低，主要是因为使用阶段所需的天然气量较少。特别是，发现二氧化碳当量平均减少27%，化石资源消耗减少25%，加权结果减少22%。
