Simplified models to simulate part load performances of air conditioning equipments

The performances of air conditioning equipments, like heat pumps, chillers or air conditioners, derive not only from the operative thermal levels, but also from the building requirement trend which normally involves frequent reductions of the full capacity. Nowadays an increasing consciousness of the importance of part load working influence on the equipment long term efficiency has stimulated the investigation about part load working behaviour of the machine. Owing to the incredible lack of experimental data about this topic, suitable new tests in laboratory and field monitoring, expressly carried on, have shown the necessity of new algorithms. In this paper these new mathematical models and their implementation in building-plant simulation codes are presented. The results obtained by their use for the calculation of the seasonal performances of HVAC systems in some typical applications are also discussed