Energy micro-piles (EMPs) constitute a promising emerging technology, able to provide both energy and structural retrofitting to existing buildings. Although a number of studies have been published on the energy performance of standard energy piles (EPs), bespoke analysis is required for EMPs due to their different geometry and peculiar design and site constraints. In this work, a parametric study is carried out by means of numerical Finite Element simulations complemented by statistical analysis, aimed at identifying the dominant parameters in maximizing EMP thermal efficiency. Two categories of parameters, namely design-dependent and site-dependent ones, are separately considered to provide guidance for practitioners on both detailed geothermal sizing and overall feasibility assessment. The parameter space is efficiently explored resorting to Taguchi Experimental Design statistical tools. Results show that different design criteria to those for EPs should be used for EMPs. Notably for the latter, contrary to the former, the diameter of heat exchanger pipes emerges as one of the most important factors promoting thermal efficiency, while being the single easiest parameter to engineer. On the other hand, while maximizing the number of U-pipes and pile diameter is crucial for EPs, it does not impact the energy performance of EMPs, due to geometry constraints and the expected occurrence of thermal interferences. Among site-dependent factors, a large ground thermal conductivity is confirmed as an important feature to ensure a high energy performance, while interesting insights are obtained about the role of basement thermal insulation in the long-term EMP thermal output.

能量微型桩 (EMP) 是一种很有前途的新兴技术，能够为现有建筑物提供能源和结构改造。尽管已经发表了许多关于标准能量桩 (EP) 的能量性能的研究，但由于 EMP 的不同几何形状和特殊设计以及场地限制，需要对其进行定制分析。在这项工作中，通过数值有限元模拟和统计分析进行了参数研究，旨在确定最大限度地提高 EMP 热效率的主要参数。两类参数，即与设计相关的参数和与场地相关的参数，分别被考虑为从业者提供详细地热尺寸和整体可行性评估的指导。借助田口实验设计统计工具可以有效地探索参数空间。结果表明 EMP 应使用与 EP 不同的设计标准。特别是对于后者，与前者相反，换热器管的直径是提高热效率的最重要因素之一，同时也是最容易设计的参数。另一方面，虽然最大化 U 形管的数量和桩径对于 EP 至关重要，但由于几何约束和预期发生的热干扰，它不会影响 EMP 的能量性能。在场地相关因素中，大的地面导热系数被确认为确保高能量性能的重要特征，