随着变速（VS）压缩机在住宅HVAC系统中应用的最新进展，现在有机会确定热泵（HPs）的尺寸，以更有效地满足美国许多气候区的热负荷和冷负荷，并限制低效电阻热的使用。这与传统单速HPs的尺寸调整指南形成对比，后者限制了冷负荷“过大”的能力，因为在冷却季节除湿不良和循环损失增加的风险。 VS drive HPs通常可以在其额定冷却能力的30-40%下运行，以减少循环损失，并可以调整风扇速度，以提供更好的室内湿度控制。详细的空气侧性能数据收集于两台VS驱动热泵上，安装在田纳西州诺克斯维尔的一个无人居住的研究室中，该研究室属于混合潮湿气候。一个系统为楼上提供空间调节，而另一个单元为楼下提供空间调节。通过操作灯、淋浴器、电器、其他插头负载等来模拟占用情况。 根据building America Research Benchmark（2008），模拟内部电力负荷和人类居住者施加在建筑空间上的敏感和潜在负荷。计算了机组的季节效率和能源使用。将年度能源使用量与之前在同一屋内测试的单速最低效率HPs进行比较。根据测量的建筑荷载和手动J设计荷载计算，检查机组的尺寸。还评估了单元尺寸对室内舒适度的影响。 引文:ASHRAE论文CD:2014 ASHRAE年会，华盛顿州西雅图

With the recent advancements in the application of variable-speed (VS) compressors to residential HVAC systems, opportunities are now available to size heat pumps (HPs) to more effectively meet heating and cooling loads in many of the climate zones in the US with limited use of inefficient resistance heat. This is in contrast to sizing guidance for traditional single-speed HPs that limits the ability to "oversize" with regard to cooling loads, because of risks of poor dehumidification during the cooling season and increased cycling losses. VS-drive HPs can often run at 30-40% of their rated cooling capacity to reduce cycling losses, and can adjust fan speed to provide better indoor humidity control.Detailed air-side performance data was collected on two VS-drive heat pumps installed in a single unoccupied research house in Knoxville, TN, a mixed-humid climate. One system provided space conditioning for the upstairs, while the other unit provided space conditioning for the downstairs. Occupancy was simulated by operating the lights, shower, appliances, other plug loads, etc. to simulate the sensible and latent loads imposed on the building space by internal electric loads and human occupants according to the Building America Research Benchmark (2008). The seasonal efficiency and energy use of the units are calculated. Annual energy use is compared to that of the single speed minimum efficiency HPs previoiusly tested in the same housey. Sizing of the units relative to the measured building load and manual J design load calculations is examined. The impact of the unit sizing with regards to indoor comfort is also evaluated.