It can take quite a bit of energy to heat water when you are talking about the gallons of water that is inside one of these tanks and I am not sure what tank functions are available in the control units programming but I am sure that they have those three functions
- Heat Hold is your normal work day heat hold keeping the tanks temp at working temp
- Preheat is set on a 7 day timer that would start heating the water to working temp before a normal workday
- Econ Hold would be a nightly temp hold that allows the tank to be brought to working temp faster by not allowing the tanks temp to fall below a certain level
I would think in logic that an econ hold overnight combined with a preheat two to three hours before workday would be the most energy efficient along with a weekend complete power down
Speaking of energy efficiency one thing I have noticed with all the actual production tanks is that non are insulated. This surprises me even a 1/4 inch of foam board insulation could greatly reduce the workload on a heater and therefore increase energy savings. Would the 5 sheets of thin stainless and insulation out-way the savings in material cost? The panels do not need to be welded in place should not in fact to allow easy access for repairs.