High investment costs are a key impediment to the energetic refurbishment of residential buildings in Germany. A versatile consumer market for smart thermostat systems suggests that they might constitute a low-investment alternative that is also accessible for tenants. Here, we assess the cost-effectiveness of smart thermostat systems under different conditions and in comparison with other mitigation measures. A dynamic investment model is set up and applied to two typical home types, an average single-family house and an average apartment, built between 1949 and 1978. The impact of variables such as relative savings, building efficiency standard, investment cost, and heating fuel price on CO₂ mitigation costs and payback times is investigated using sensitivity analyses. Smart thermostat systems are cost-effective for the two home types if relative savings of at least 5.7% (single-family house) and 7.7% (apartment) are achieved. Both CO₂ mitigation costs and payback times strongly decrease with increasing relative savings for values below 10%. Similarly, the level of savings needed to achieve cost-effectiveness strongly increases with increasing building efficiency for values below 100 kWh/m²a. We demonstrate that smart thermostat systems can be a low-investment measure to cost-effectively reduce CO₂ emissions and energy consumption in the residential building sector. They should be used primarily in buildings with a medium to low efficiency standard, where energetic refurbishment is unlikely in the coming years. To assess the economic mitigation potential of smart thermostat systems, broad and granular empirical data on realized heating energy savings is urgently needed.

高昂的投资成本是德国大力整修住宅建筑的主要障碍。智能恒温器系统的多功能消费市场表明，它们可能构成低投资替代方案，租户也可以使用。在这里，我们评估了智能恒温器系统在不同条件下的成本效益，并与其他缓解措施进行了比较。建立了动态​​投资模型，并将其应用于两种典型的房屋类型，即1949年至1978年之间建造的平均单户住宅和平均公寓。变量的影响，例如相对储蓄，建筑效率标准，投资成本和供暖CO ₂燃料价格使用敏感性分析研究缓解成本和投资回收期。如果相对节省至少5.7％（单户住宅）和7.7％（公寓），则智能恒温器系统对于这两种类型的房屋而言具有成本效益。对于低于10％的值，CO ₂缓解成本和投资回收期都会随着相对节省的增加而大大降低。同样，对于低于100 kWh / m ² a的值，随着建筑效率的提高，实现成本效益所需的节省水平也大大提高。我们证明了智能恒温器系统可以作为一种低投入的措施来经济有效地减少CO ₂住宅建筑部门的排放和能源消耗。它们应主要用于中低效率标准的建筑物，在未来几年内不太可能进行大力翻新。为了评估智能恒温器系统的经济缓解潜力，迫切需要关于已实现的热能节省的广泛而详尽的经验数据。