Energy savings through variable speed compressor heat pump systems

In the present study, four different kind of HVAC systems based on heat pump technology at three site locations (Milan, Rome and Palermo) were implemented and simulated. The simulated HVAC systems consisting of: ground source borehole (W-W (bh)); ground water wells (W-W(well)); air to water (A-W); air to air (A-A) heat pump systems applied for heating and cooling applications in a low energy residential building. In particular, the study is focused on comparative performance of single speed and variable speed compressor equipments based on heat pump technology. In this respect, the chosen site locations characterize the typical climatic zones of Italy (Milan- Continental, Rome-Intermediate and Palermo-Mediterranean). The results demonstrated that variable speed equipments can achieve considerable energy savings especially in the air source heat pump system applications. The estimation pointed out that variable speed heat pump equipment can enhance energy savings in comparison to constant single speed equipments especially at Palermo and Rome, in particular during heating season where most of the time, the equipments operate at lower part load ratios (PLR).