Calendar controlled operation
Grundfos COMFORT pumps with AUTOADAPT are controlled by a combination of the water temperature detected in the system, the ‘Tstart’ and ‘Tstop’ temperature settings, and the calendar log.
Every time hot water is tapped, the water temperature changes, and this is registered via a special filter and logged in the tapping calendar. In fact, even a circulator pump starting will cause a change in temperature – so the AUTO-ADAPT algorithm decides whether a change is caused by pump starting or by hot water tapping, and only logs the latter in the tapping calendar.
The tapping calendar covers 14 days of tapping history (to make sure a pattern is defined), and each calendar day is divided into 20-minute time slots. Whenever hot water is tapped, a ‘T’ (for tapping) is logged in the appropriate time slot in the calendar. When the pump has been on standby for eight hours, the system is automatically flushed for 15 minutes. An ‘F’ (for flushed) is logged in the calendar.
Based on the calendar log (i.e., the time slots where the most ‘T’s have been recorded), AUTOADAPT calculates when hot water is likely to be tapped next, and activates the temperature-dependent hysteresis control 20 minutes prior to the expected demand. It is deactivated again when no more tapping is expected.
Grundfos_COMFORT_Calendar controlled operation_article.pdf (size: 0.6MB)