Partial model to calculate the icing factor based on the data available in the
signal bus sigBus
of the heat pump.
The icing factor is a heat transfer modifier between 0 and 1, whereas 0 indicates no heat transfer occurs and 1 indicates the heat transfer is unaffected.
See the documentation of BuildingSystems.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.BaseClasses.PartialRefrigerantCycle for further information.