The screw air-source heat pump can cause incessant high noise levels during operation, which might hinder adoption of this energy-efficient heat pump. First, acoustic measurements and comparison testing were performed in this research. The measurements revealed that the compressor is the main noise source of the heat pump, and it shows a multipeak frequency distribution and a wide frequency spectrum under different work conditions, with multiple peaks at 63, 250, and 1000 Hz. Then, a compressor sound insulation cover with broadband absorption was proposed, and it was experimentally proven that the insulation cover can reduce the maximum sound pressure level of one unit from 89.8 dBA to 79.1 dBA. Third, we proposed several noise reduction strategies and compared their noise reduction effects using computer simulation. The results showed that the noise problem can be effectively improved through the rational design of the sound barrier and the layout and opening options of heat pump. The distance between the sound barrier and heat pump and the sound attenuation due to diffraction ΔL_d exhibit a U-shaped relation. For buildings of different heights, the optimal heights of noise barrier are proposed. The 5.5-meter is the optimal height of the sound barrier for single-story buildings. The conclusions can be applied to other building projects for heat pump noise reduction.

螺杆空气源热泵在运行过程中会产生持续的高噪音，这可能会阻碍这种节能热泵的采用。首先，本研究进行了声学测量和对比测试。测量结果表明，压缩机是热泵的主要噪声源，在不同工况下表现出多峰频率分布和较宽的频谱，在63、250和1000 Hz处有多个峰值。然后，提出了一种宽带吸收的压缩机隔音罩，并通过实验证明，该隔音罩可以将一台机组的最大声压级从89.8 dBA降低到79.1 dBA。第三，我们提出了几种降噪策略，并通过计算机模拟比较了它们的降噪效果。结果表明，通过声屏障的合理设计以及热泵的布置和开口选择，可以有效改善噪声问题。声屏障与热泵之间的距离与衍射声衰减ΔL d_呈U型关系。针对不同高度的建筑，提出了声屏障的最佳高度。5.5米是单层建筑声屏障的最佳高度。该结论可应用于其他热泵降噪建筑项目。