Does the outdoor heat pump unit require a defrost cycle during long cold spells and does this lead to unavailability of heating during the cycle as with VRF systems?
Yes and No! During long cold spells, Yes, the outdoor heat pump unit will ice up; this is normal for any heat pump unit including all VRF systems. HOWEVER unlike VRF systems which have to STOP heating the building during the de-ice period and reverse cycle (so that the indoor unit coils are then cold evaporators and the outdoor coil is warm), the Caloris system can use its water system as a buffer and carry on heating occupied spaces! Thereforeno – it does not lead to heating unavailability. Please note, while de-icing, which takes approx. 15 minutes, all VRF systems will stop providing heating to the end users, often resulting in users complaining about cold drafts from the indoor evaporators and refrigerant/control valve noises. Worse still, energy is consumed by the refrigerant compressor in the de-frost cycle. The difference in comfort control during de-icing is a major advantage over VRF installations.
Yes and No! During long cold spells, Yes, the outdoor heat pump unit will ice up; this is normal for any heat pump unit including all VRF systems. However, unlike VRF systems which have to STOP heating the building during the de-ice period and reverse cycle (so that the indoor unit coils are then cold evaporators and the outdoor coil is warm), the Caloris system can use its water system as a buffer and carry on heating occupied spaces! Thereforeno – it does not lead to heating unavailability. Please note, while de-icing, which takes approx. 15 minutes, all VRF systems will stop providing heating to the end users, often resulting in users complaining about cold drafts from the indoor evaporators and refrigerant/control valve noises. Worse still, energy is consumed by the refrigerant compressor in the de-frost cycle. The difference in comfort control during de-icing is a major advantage over VRF installations.
